Plants



Alder

plant diagnostic_database

Alder (Alnus spp.)

 

Alnus

Affected Area:
  • Leaves                                         
  • Stems, twigs, and small branches 
  • Larger branches or trunks

Plant Information:

The genus Alnus includes about 30 species of deciduous trees and shrubs in NorthAmerica, Europe, Asia, and parts of South America.  The leaves are simple,
alternately arranged, and most often serrated.  Male and female catkins appear in the spring before the leaves emerge.

 

 

 

 

 

 

  

 

 

Affecting Leaves:
Signs or Symptoms           Cause 
Beadlike galls on both sides of leaf surfaces Eriophyid mite
Affecting Stems, Twigs or Small Branches:
Signs or Symptoms Cause
Frothy spittlemass Spittlebugs (Clastoptera juniperina)
Cottony material Alder aphid
Affecting Larger Branches or Trunks:
Signs or Symptoms                                                                   Cause                                                                                                       
Discolored areas, dead bark containing small pimple-like fruiting bodies Cytospora canker (Valsa spp.,Leucostoma spp.)

 

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Apple

plant diagnostic_database

Apple, Crabapple (Malus spp.) 

 

malus

Affected Area:
  • Leaves
  • Stems, twigs and     
    small branches 
  • Larger branches
    or trunks 
  • Ground line area of trunk    
  • Roots
  • Fruit 

Plant Information:

This plant...

 

 

 

 

 

 

 

 

 

  • USDA Plants Database
  • Lady Bird Johnson Wildflower Center
  • Elisabeth Miller Library
  • Oregon State University Landscape Plants 
Affecting Leaves:
Signs or Symptoms Cause 
Large holes chewed in leaves Speckled green fruitworm, Redhumped caterpillar (Schizura concinna) , or Forest tent caterpillar.
Silken tents produced Western tent caterpillar or Fall webworm(Hyphantria cunea)
Caterpillar living within a case Snailcase bagworm (Apterona helix)
Terminal leaves curled and tied together with silk Fruittree leafroller or Obliquebanded leafroller 
Skeletonized leaves Apple and thorn skeletonizer (Choreutis pariana) or Apple flea beetle (Phyllotretaspp.)
"Shothole" feeding wounds in leaf, usually with sucker growth Apple flea beetle (Phyllotreta spp.)
Raised leafmines Western tentiform leafminer
(Phyllonorycter elmaella)
White powdery material on upper or lower surface of leaf Powdery mildew
Pale green or yellow leaves Iron chlorosis. See Nutrient Deficiencies
Rust orange spots Juniper rusts
Black mold on surface of leaf Apple scab (Venturia inaequalis)
Rusty blisters or scabby patches on leaves Blister mites. See Eriophyid Mites
Bronzing of leaves Two-spotted spidermite or McDaniel spider mite
Curling distortions of new growth in spring Rosy apple aphid
Blackened and wilted leaves Fireblight (Erwinia amylovora)
Affecting Stems, Twigs or Small Branches:
Signs or Symptoms Cause
Twigs shredded by a line of multiple punctures Cicada oviposition wounds
Blackened, wilting, and crooked tips Fireblight (Erwinia amylovora)
Black beetle tunneling, with small exit holes Shothole borer
Scales on twigs Oystershell scale or European fruit lecnium
Cottony insects on twigs Woolly apple aphid or Mealbugs
Discolored areas, dead bark containing small pimple-like fruiting bodies (pycnidia) Cytospora canker (Valsa spp.,Leucostoma spp.)

 

Affecting Larger Branches or Trunks:
Signs or Symptoms Cause
Boring into trunk Flatheaded appletree borer - (Chrysobothris mali)
Bark beetle tunneling, small exit holes Shothole borer
Cottony insects on trunk and/or roots Woolly apple aphid
Internal decay and/or shelf-like fruiting structures (conks) Decay fungus
Wilting and dieback of portions of tree, originating from roots Verticillium wilt (Verticillium spp.)
Affecting Ground Line Area of Trunk:
Signs or Symptoms Cause
Discolored tissue under bark at ground line Phytophthora root rot (Phytophthoraspp.)
Galls at ground line  Crown gall
Affecting Roots:
Signs or Symptoms Cause
White root decay and white mycelial fans between bark and wood Armillaria root disease (Armillaria spp.)

 

Affecting Fruit:
Signs or Symptoms Cause
Tunneling in fruit Codling moth (Cydia pomonella)
Scarring or scabbing of fruit Fruittree leafroller, Hail injury, or Apple scab (Venturia inaequalis)
Pitted, scarred fruit Tarnished Plant Bug (Lygus lineolaris)

 

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Apricot

plant diagnostic_database

Stone Fruits:  Apricot, Cherry Chokecherry, Peach, Plum, etc.

(Prunus spp.) 

Prunus

Affected Area:

Plant Information:


The genus Prunus is comprised of nearly 200 species of five subgenera:  plums and apricots, almonds and peaches, umbellate cherries, deciduous racemose cherries, and the evergreen racemose cherries.  The species of this genus range from shrubs to trees over 90 ft. tall.  Over 100 species have been cultivated as either ornamentals or as food crops.  Trees for fruit production and many ornamentals are generally propagate by budding or grafting, while seed propagation is reserved for generation of rootstocks and breeding programs.  The most common rootstock:scion combinations are:  almond:almond and plum; apricot:apricot; mazzard cherry:sweet cherry; mahaleb cherry:sweet and sour cherry; peach:peach, almond, apricot, plum; American plum:plum in cold regions; Bessey cherry:dwarf peaches. 

 

Affecting Whole Plant:
Signs or Symptoms Cause 
Tree decline in vigor Phytophthora root rot (Phytophthoraspp.), Cytospora Canker (Valsa spp.,Leucostoma spp.), or Verticillium wilt(Verticillium spp.)
Affecting Leaves:
Signs or Symptoms Cause 
Leaves chewed, no associated webbing Pearslug (Caliroa derasi)
Upper surface of the leaf skeletonized Pearslug (Caliroa cerais) or Apple Thorn Skeletonizer
Webbing associated with chewing Fall webworm (Hyphantria cunea Drury),Ugly Nest caterpillar (Archips cerasivorana), or Western tent caterpillar(Malacosoma californicum)
Leaves with small, circular holes Shot hole disease 
White flecking injuries  White apple leafhopper (Typhlocyba pomaria McAtee) or Lacebug (Corythuca padi), on chokecherry (Corythuca spp.)
White powdery material on upper or lower surface of leaf Powdery mildew
Leaves yellow Iron chlorosis or X-disease
Leaves with small, pouch or finger-like projections Fingergall mites (Phytoptus species)
New leaves curled Aphids: Green peach aphid (Myzus persicae), Leafcurl plum aphid (Anuraphis helichrysi), or Black cherry aphid (Myzus cerasi)
New leaves curled and thickened and red/purple Peach leaf-curl disease
Affecting Larger Branches or Trunks:
Signs or Symptoms Cause 
Black galls on branches Black knot of cherry (Apiosporina morbosa) 
Stem decay and/or hoof-shaped fruiting body (conk) Decay fungus (Phellinus pomaceus)
Scales Scale: European fruit lecanium (Parthenolecanium corni) or Oystershell scale (Lepidosaphes ulmi)
Small pinhead-sized exit holes in branches Shothole borer (Scolytus rugulosus)
Branches die back Cytospora canker (Valsa spp.,Leucostoma spp.) or Shothole borer (Scolytus rugulosus)
Gumming and dark colored branches Shothole borer (Scolytus rugulosus), or Cytospora canker (Valsa spp.,Leucostoma spp.) or Bacterial Blight (Pseudomonas syringae)
Dead bark with discoloration and small pimple-like fruiting bodies (pycnidia) Cytospora canker (Valsa spp.,Leucostoma spp.)
Wilting and dieback of portions of tree, originating from roots Verticillium wilt (Verticillium spp.)
Affecting Ground Line Area of Trunk:
Signs or Symptoms Cause 
Discolored tissue under bark at ground line Phytophthora root rot (Phytopthora sp.)
Gall at ground line Crown gall (Agrobacterium tumefaciens)
Affecting Fruit:
Signs or Symptoms Cause 
Fruit tunneled European earwig (Forficula auricularia L.)
Fruit with sunken, corky areas Plant bug (Lygus species), Hail injury, or Boxelder bug (Boisea trivittata)
Puncture wounds in fruit Bird damage (Robins, finches, etc.)
Chokecherry fruit enlarged, hollow Chokecherry gall midge (Contarinia virginianae)
Maggots in cherry fruit Western cherry fruit fly (Rhagoletis indifferens Curran

 

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Ash

plant diagnostic_database

                                  Ash (Fraxinus spp.)                          

Fraxinus        

Affected Area:
  • Leaves                                        

                                

 
 
 

 

  • Flowers                                                           

Plant Information:

The genus Fraxinus is comprised of about
70 species worldwide, 16 of which are
native to North America.  Ashes are easy
to identify because they are one of a few
groups of trees that are both opposite and
pinnately compound.  The fruit of these
trees is a single-winged samara resembling
a canoe.  The bark is crisscrossed with ridges and resembles a woven net.

 

 

Affecting Leaves:
Signs or Symptoms           Cause 
Leaves chewed:  normal chewing injuries, primarily confined to leaf edges                                                                         Browheaded AshSawfly (Tomostethusmulticinctus); Forest tent caterpillar (Malacosoma dissetria); Fruittree leafroller (Archips argyrospilus)
Smooth semicircular cuts made on leaf edge Leafcutter Bees (Megachile spp.).
Blackened spotting of leaves Ash Anthracnose (Apiognomonia spp.
Leaflets being distorted and/or killed back  Ash plant bug (Tropidosteptes amoenus
Flecking wounds on leaves Ash plant bug (Tropidosteptes amoenus) or Lacebug (Corythuca spp.
Leaves bronzed: “Brittle-leaf” condition Eriophyid mites 
Leaflets thickened and curled at midrib Ash midrib gall midge (Contarinia canadensis
Leaves tightly curled and thickened Leafcurl ash aphid (Prociphilus fraxinifolii
General distortion of leaf, with thickened veins Herbicide injury
White powdery material on upper or lower surface of leaf Powdery mildew 
Wilting of portions of tree: originating from roots                                                                          Verticillium wilt (Verticillium spp.
Affecting Stems, Twigs or Small Branches:
Signs or Symptoms Cause
Twig dieback with small exit holes or ventilation holes visible                               Ash bark beetles (Hylesinus spp.)                                                                   
Twig dieback with small pimple-like fruiting bodies (pycnidia) in the bark Cytospora canker (Valsa spp., Leucostoma spp.)
Witches' brooming symptoms                         Ash yellows (Phytoplasma
Scales                                                        Oystershell scale (Lepidosaphes ulmi) or European fruit lecanium (Parthenolecanium corni)
Affecting Larger Branches or Trunks:
Signs or Symptoms                                Cause
Tunneling in trunk                                                                                                                                                                                                                                                                                                                  Lilac/Ash borer, Banded ash clear wing, (Podosesia syringa); Ash bark beetles (Hylesinus spp.); Redheaded ash borer(Neoclytus acuminatus)                                                                                                                                           
Masses of caterpillars resting on bark   Forest tent caterpillar (Malacosoma disstria Hubner)  
Discolored areas and dead bark containing small pimple-like fruiting bodies (pycnidia)   Cytospora canker (Valsa spp.,Leucostoma spp.)  
Clear to white oozing or frothy malodorous liquid exiting from wounds   Bacterial wetwood/slime flux  
Large, dead areas of bark on southwest side of trunk Winter sunscald
Open wounds, internal decay, swollen areas on stem Stem decay fungi (Perenniporia fraxinophila, Phellinus punctatus, and various fungal genera)
Fungal fruiting bodies (mushrooms, conks) present Stem decay fungi (Perenniporia fraxinophila, Phellinus punctatus, and various fungal genera)
Wilting and dieback of portions of tree, originating from roots Verticillium wilt (Verticillium spp.)
Affecting Flowers:
Signs or Symptoms:                                          Cause:                                                                                                      
Distorted flowers                                                                          Ash flower gall mite (Eriophyes fraxiniflora)

 

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Asparagus

plant diagnostic_database

                     Asparagus (Asparagus officinalis.)                          

Asparagus        

Affected Area:
  • Leaves                                     
  • Spears                                                

Plant Information:

Asparagus is a cool season perennial grown for its young shoots which are one of the first vegetables to harvest in the spring.  Asparagus cultivars can be grouped according to spear color - dark green, whitish-green or purple.  Asparagus can be planted from seed or 1-year old crowns.  If your soil is heavy plant on slightly raised beds. Asparagus is very hardy and grows best at elevations up to 5,500' on sites that have moist soil and full sun.  Asparagus prefers a light, deep, well-drained soil with a pH of 6.0-6.7, but will tolerate a pH over 7.0.  Asparagus requires high levels of phosphorus and potassium.

Do not harvest new plantings until they are at least 2 years old.

 

 

 

Affecting Leaves:
Signs or Symptoms           Cause 
Yellow leaves, slow growth                                                                       Nitrogen deficiency.
Yellow leaves, dwarfed plants, plants form bushy rosettes. Asparagus aphids
Yellow leaves, wilting, dieback of crown. Fusarium wilt (Fusarium oxysporum)
Foliage turns reddish brown and drops; small reddish spots on main stems and branches. Rust
Defoliated plants/deformed spears. Several insect pests cause this kind of injury, including Asparagus beetles
Affecting Spears:
Signs or Symptoms Cause
Chewed stalks at soil line, seedlings clipped off at soil line.                              Cutworms (Noctuidae spp.)                                             
Large lesions at base of spears or below soil line; small spears. Fusarium wilt(Fusarium oxysporum)
Spears turn brown near soil line.              Phytopthora crown rot (Phytophthora spp.)
Bracts of spears are spread out.                             Feathering caused by high temperatures (>85° F.)

 

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Aspen

plant diagnostic_database

                                 Aspen (Populus tremuloides)                          

Populus tremuloides        

Affected Area:
  • Leaves                                        

Plant Information:

Populus tremuloides or quaking aspens,
are one of the most widely distribute tree
in North America  This is a broadleaf deciduous small tree with roundish leaves, white
undersides, and flat petioles that cause the
leaves to flutter in the wind.  This tree can
grow in sun or part shade, adaptable to
nearly all types of soil, is fast growing, and relatively short lived.

 

 

Affecting Leaves:
Signs or Symptoms           Cause 
Leaves curled                                                                 Large aspen tortrix (Choristoneura conflictana) 
Leaves curled with tent of silk produced Western tent caterpillar (Malacosoma fragilis)
No curling or silk associated with injury Forest tent caterpillar (Malacosoma disstria Hubner), Redhumped caterpillar(Schizura concinna), Cottonwood leaf beetle (Chrysomela scripta), or Sawflies(cimbidae)
Masses of dark, spiney caterpillars on leaves Spiny elm caterpillar [Mourning Cloak Butterfly] (Nymphalis antiopa) - No significant damage.
Leaves spotted: Young leaves blackened Shoot blight (Venturia tremulae) or Frost injury
Black irregular spots on leaves Septoria leaf spot and canker (Septoria populicola)
Dark round spot which drops out of leaf, leaving shothole appearance Ink spot (Ciborinia whetzelii)
Black spots with yellow margins Marssonina blight (Marssonina populi)
Rust or orange colored spots Conifer-aspen rust (Melampspora spp.)
Underside spots with small depressions and patches of brown leaf hairs Eriophyid mites
Leaves generally distorted or thickened; whole leaf or set of leaves so distorted Poplar vagabond aphid(Erisomatidae spp.)
Edge of leaf folded into a series of ridges Eriophyid mites
Red, thickened folds along leaf veins Gall midge
Leaves with serpentine, silvery tunneling Aspen leafminer (Phyllocnistis populiella)
Sucking insects on leaves Clear-winged aspen aphid (Chaitophorus populifoliae) or Leafhoppers
White powdery material on upper or lower surface of leaf Powdery mildew (Erysiphe cichoracearum)
Yellowed leaves Root damage caused by under or over watering or Iron chlorosis
Affecting Stems, Twigs or Small Branches:
Signs or Symptoms Cause
Twig dieback; Shoot curled into a shepherd’s crook        Shoot blight (Venturia tremulae)
Meandering tunnels under bark Flatheaded borer Agrilus spp.
Twig dieback with small pimple-like fruiting bodies (pycnidia) in the bark                     Cytospora canker (Valsa spp.,Leucostoma spp.)
Scales on bark                                  Oystershell scale (Lepidosaphes ulmi)
Affecting Larger Branches or Trunks:
Signs or Symptoms                                Cause
Areas of dead bark, with discoloration and small pimple-like fruiting bodies (pycnidia)                                                                                                                                                                                                                                                                                                   Cytospora canker (Valsa spp.,Leucostoma spp.)                                                                                                                                   
Small (1/6 - in) gray or brown oystershell shaped objects on bark Oystershell scale (Lepidosaphes ulmi)
Rounded and often rough swellings on branches Aspen gall (Diplodia tumefaciens)
Oozing liquid from wounds with clear to white oozing or frothy malodorous liquid Bacterial wetwood/slimflux
Orange staining ooze Poplar borer (Saperda calcarata)
Cottony growth on branches and/or trunk Woolly aphid 
Swellings in branches or trunk Poplar borer (Saperda calcarata)
Tunneling with coarse sawdust often forced from opening Poplar borer (Saperda calcarata)
Regular rows of holes in trunk Sapsuckers
Open wounds, internal decay, or swollen areas in stem Stem decay fungi (Phellinus tremulae, Ganoderma applanatum, and other fungal genera)
Fungal fruiting bodies (mushrooms, conks) present Stem decay fungi (Phellinus tremulae, Ganoderma applanatum, and other fungal genera)
Affecting Roots and Ground Line Area:
Signs or Symptoms:                                          Cause:                                                                                                      
White root decay with white mycelial fans between bark and wood                        Armillaria root disease (Armillaria mellea)

 

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Basswood

plant diagnostic_database

                                 Basswood, Linden (Tilia spp.)                          

Tilia        

Affected Area:
  • Leaves                                                                   


                                                       

Plant Information:


The genus Tilia consists of about 40 species of large or medium-sized deciduous trees.  Trees of this genus thrive in loamy, moist, fertile soil, but will tolerate poor soils and adverse conditions.  Trees of this genus vary greatly in size, shape, leaf, and growth rate.  Lindens are primarily used as ornamental shade and street trees.  The wood of Linden is generally not suitable for lumber as it is soft and rots readily.  The name "basswood" or "bastwood" is dervided from the word bast (inner bark) that consists of long, tough fibers once used in the production of mats and clothing.

 

 

Affecting Leaves:
Signs or Symptoms           Cause 
Leaves being chewed                                                             Fruittree leafroller (Archips argyrospila) or Speckled green fruitworm (Orthosia hibisci)
Small pouch galls form on leaf surface Linden fingergall mite (Eriophyid mite)
Velvety patches on underside of leaves (littleleaf linden) Linden fingergall mite (Eriophyid mite)
Pale green or yellow leaves Iron chlorosis
Leaves strongly cupped Herbicide injury
Aphids Linden aphid (Myzocallis tiliae)
Wilting and dieback of portions of tree, originating from roots Verticillium wilt (Verticillium spp.)
Affecting Stems, Twigs or Small Branches:
Signs or Symptoms Cause
Large cottony insect develops in late spring Cottony maple scale (Pulvinaria innumerabilis)
Affecting Larger Branches or Trunks:
Signs or Symptoms                                Cause
Areas of dead bark with discoloration and small pimple-like fruiting bodies (pycnidia) Cytospora canker (Valsa spp.,Leucostoma spp.)
Wilting and dieback of portions of tree, originating from roots Verticillium wilt (Verticillium spp.)

 

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Beans

plant diagnostic_database

                                 Beans (Phaseolus vulgaris)                          

Bean (Phaseolus vulgaris)        

Affected Area:
  • Leaves                                        
  • Fruit                                                         

Plant Information:

Snap beans come in various shapes and colors and are eaten in the immature stage.  Dry or field beans also come in assortment of shapes and colors and are harvested for storage in the mature form.  There are two kinds of snap beans:  pole or bush types.  Pole types produce later harvests over longer periods, but must be supported.  Bush types have a more concentrated maturity and come on earlier.  Beans should be planted when soil temperatures reach 60 degrees F.  Beans prefer a pH of 5.5-7.0, and need adequate phosphorus and potassium for a good crop.

 

 

 

 

Affecting Leaves:
Signs or Symptoms           Cause 
Yellow, curling leaf margins, wilted plants; flowers and pods drop                                                 Large aspen tortrix (Choristoneura conflictana) 
Yellow, distorted new growth. Tarnished plant bug (Lygus pratensis)
Yellow leaves, slow growth Nitrogen deficiency
Curled, yellow, withered leaves Bean aphidsBean mosaic, or Curly top
Small reddish-brown specks, especially on leaf undersides; leaves yellow and drop Rust
White, stippled leaves, which later become bronzed, stunted growth Mites
Meandering tunnels in leaves Leaf miners
Puckered leaves curl downwards; plants stunted Flea beetles (Phyllotreta spp.)
Affecting Seeds, Seedlings, or Roots:
Signs or Symptoms Cause
Stems rot near soil line and plant collapses; seeds do not germinate Damping off
Poor germination, deformed, spindly seedlings with killed growing point Seed corn maggots
Affecting Fruit:
Signs or Symptoms                                Cause
Blossoms drop Excessive heat or rain, or Western flower thrips (Frankliniella occidentalis)
Pitting and russeting of pods May be due to chilling injury
Water-soaked or brown patches on pods; yellow, blotched seeds Bacterial blight (Pseudomonas syringae)
Holes chewed in pods Caused by several worms including the following: Cabbage looperBeet armyworm (Euxoa auxiliaris) , Corn earworm (Heliothis zea) , or European corn borer (Ostrinia nubilalis)

 

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Beet

plant diagnostic_database

                                 Beet (Beta vulgaris)                          

Beet        

Affected Area:
  • Leaves                                        
  • Roots                                                        

Plant Information:


Beets can be either be directly sown into the garden once the soil has warmed to 45 degrees or can be sown into containers for later transplanting.  For a continuous supply of greens and small beets, sow seed at two week intervals until two months prior to first heavy frost.  Beets should be sown at a depth of 1/2-1 inch, with 2 inch spacing between plants, and 15-24 inches between rows.  Beets are generally ready to harvest within 60 days, or two-three weeks sooner if transplanted.  


 

 

 

Affecting Leaves:
Signs or Symptoms           Cause 
Yellow leaves, older first; stunted plants Nitrogen deficiency
Yellow, curled leaves; stunted plants. Aphids
Purplish patches on leaves Phosphorus deficiency(common in cool spring soils)
Brown leaf tips May be a reaction to bright sun and heat (temperatures above 80° F.)
Tan spots with dark borders Cercospora leaf spot (Cercospora spp.)
Meandering, white or translucent, irregular tunnels in leaves Leafminers
Small holes, shot-hole injury Flea beetles (Phyllotreta spp.)
Affecting Roots:
Signs or Symptoms Cause
Internal black, dead, hard spots Boron deficiency
Forked roots Forked roots
Small, poorly developed roots Small, poorly developed roots
Light color and wider zoning of rings in root High temperature and fluctuating soil moisture

 

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Birch

plant diagnostic_database

                                 Birch (Betula spp.)                          

Betula        

Affected Area:
  • Leaves                                        

Plant Information:


The genus Betula is comprised of nearly 50 species of deciduous trees and shrubs, 14 of which are native to the United States.  Flowers of this genera are monoecious and borne in catkins.  Male catikins are formed late in the season, persist through the winter, and open in the spring.  Female catkins appear with the leaves on terminal spurs-like branches.  Birches are known to hybridize readily in the wild and in cultivation.  

 

 

 

Affecting Leaves:
Signs or Symptoms           Cause 
Leaves with tan-colored, blotchy mines
Birch leafminer (Fenusa pusilla) or Aphids(several, species unknown)
Affecting Trunk and Larger Branches:
Signs or Symptoms Cause
Tunneling, raised, papery bark, or dieback Bronze birch borer (Agrilus anxius Gory)
Areas of dead bark With discoloration and small pimple-like fruiting bodies (pycnidia) Cytospora canker (Valsa spp.,Leucostoma spp.)

 

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Boxelder

plant diagnostic_database

                                 Boxelder (Acer negundo)                          

Boxelder        

Affected Area:
  • Leaves 
  • Seeds                                      

Plant Information:

Boxelder or ash-leaved maple is a deciduous multi-stemmed tree that grows 30-50 ft. in height.  The opposite leaf arrangement is characteristic to the maple family, but this species is compound (ash-like), usually 3-5 leaflets.  The tree is extremely hardy, is native to riparian areas, but is adaptable to other sites.  


 

 

 

Affecting Leaves:
Signs or Symptoms           Cause 
Leaves curled, chewed Boxelder leafroller (Archips negundanus)
Leaves thickened around midrib Gouty veingall midge (Continaria negundinis)
New growth is small, distorted Eriophyid mites
Sucking on leaves, honeydew often present Boxelder and maple aphids (Periphyllus spp.)
Small cottony indentations on leaf underside Eriophyid mites
Masses of reddish eggs on leaves Boxelder bug (Boisea trivittata)
Affecting Trunk and Larger Branches:
Signs or Symptoms Cause
Discolored areas, dead bark containing small pimple-like fruiting bodies (pycnidia) Cytospora canker (Valsa spp.,Leucostoma spp.)
Open wounds, internal decay, swollen areas in stem Stem decay fungi (Pholiota sp., Pleurotussp., and various fungal genera)
Fungal fruiting bodies (mushrooms, conks) present Stem decay fungi (Pholiota sp., Pleurotussp., and various fungal genera)
Affecting Seeds:
Signs or Symptoms Cause
Feeding on seeds Boxelder bug (Boisea trivittata)

 

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Broccoli

plant diagnostic_database

                                 Broccoli (Brassica oleracea var. botrytis)                          

broccoli        

Affected Area:

Plant Information:


 Broccoli is a hardy vegetable in the Brassicaceae (crucifer or cabbage) family.  This plant can provide two crops a year as it grows during the cool seasons of the year.  Transplants are recommended to give the best start for spring planting, but direct sowing can produce succesful plants.  Plant seeds 1/4-1/2 inch deep or transplants slightly deeper than originally grown.  The edible portion of the broccoli are the unopened, compact, inflorescences and the attached stem.  When harvesting, removing the central head will stimulate the growth of side shoots to develop for later harvests. 

Affecting General Plant and Roots:
Signs or Symptoms           Cause 
Yellow, stunted plants that wilt during bright, hot days and recover at night. Usually a sign of root injury. Pull up plant and check for root-knot nematodes or cabbage root maggots (below)
Irregularly shaped galls Root-knot nematode (Meloidogyne spp.)
Roots are riddled with slimy, winding tunnels Cabbage root maggots
Affecting Leaves:
Signs or Symptoms Cause
Yellow v-shaped spots on leaf margins with blackened veins; stems show internal black streaks Black rot (Xanthomonas campestris)
Yellowish leaves, lower leaves drop; stunted plants may have twisted stems, usually occurs soon after transplanting Fusarium yellows (Fusarium oxysporum)
Yellow leaves, older leaves first, slow growth Nitrogen deficiency
Older leaves whitish and drooping Cold injury, wind injury
Yellow, curled leaves; stunted plants Aphids
White to bronze spots, wilted leaves Thrips
White spotting, then brown, often distorted leaves that wilt and die Harlequin bug (Margantia histrionica)
Light-colored spots on leaves turn papery; white mildew on leaf undersides Downy mildew (Peronospora effusa)
Small pitted holes, shot-hole injury Flea beetles (Phyllotreta spp.)
Large hole in leaves; outer leaves riddled, excrement found at base of cabbage head Imported cabbage worm (Pieris rapae),Cabbage looperDiamondback moth(Plutella xylostella), or Grasshoppers(Melanoplus spp.)
Leaves with meandering tunnels Leafminer
Affecting Inflorescences or Heads:
Signs or Symptoms Cause
Hollow stem, smaller, uneven head formation Excess nitrogen, or potassium deficiency
Black areas in center of head Rot due to water collecting inside head
Small heads that form prematurely (bolt) High temperature stress, poorly adapted variety, or exposure of plants to fluctuating warm/cool temperatures

 

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Brussels Sprouts

plant diagnostic_database

                                 Brussels Sprouts (Brassica oleracea var. gemmifera)                          

Brussels Sprouts        

Affected Area:

Plant Information:

Brussel sprouts is one of the most hardy members of the cabbage family.  It can tolerate a lower temperture (<40 F) and pH (5.5-6.8) than any of the other brassicas. Brussel sprout plants become about 2 1/2' tall, bearing may 1-2" ball-like sprouts resembling minature cabbages.  Plant brussel sprouts 18" apart in rows 3' apart.  Jade Cross Hybrid and Prince Marvel do well in our climate.

 

Affecting Leaves:
Signs or Symptoms           Cause 
Tan to dark-brown leaf margins Heat injury
Poor sprout development Nitrogen or potassium deficiency; poor variety choice
Sticky, blackened sprouts Aphids
Holes in leaves Imported cabbage worm (Pieris rapae) or Cabbage looper
Affecting Roots:
Signs or Symptoms Cause
Yellow, stunted plants that wilt during bright, hot days and recover at night. Usually a sign of root injury. Pull up plant and check for root-knot nematodes or cabbage root maggots (below)
Irregularly shaped galls Root-knot nematode (Meloidogyne spp.)
Roots are riddled with slimy, winding tunnels Cabbage root maggots

 

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Cabbage

plant diagnostic_database

                                 Cabbage (Brassica oleracea var. capitata)                          

Cabbage        

Affected Area:

Plant Information:

Cabbage is a hardy, cool season crop.  There are green, red and savoy types shich come in early, midseason and late varieties. All need cool moist conditions.  Most early varieties weigh about 3 pounds, miseason and late varieties weigh 4-6 pounds.  Cabbage does well in fertile well-drained soils with a pH of 6.0 to 6.8.  Cabbage is a heavy feeder requiring nitrogen and phosphorus in high levels.  Cabbage has shallow roots and thus needs an abundance of water.  Plant seedlings out a couple weeks before the last frost date 2' apart in rows 3' apart.  Mulching will help conserve moisture and control weeds.  Uneven moisture after heads are formed will cause splitting.

 

Affecting Leaves and Heads:
Signs or Symptoms           Cause 
Yellow V-shaped spots on leaf marginsheads dwarfed and often one-sided Black rot (Xanthomonas campestris)
Stunted, wilted, yellow plants. Youngest plants and seedlings are affected Root maggots
Yellowish leaves, lower leaves drop; stunted plants may have twisted stems, usually occurs soon after transplanting Fusarium yellows (Fusarium oxysporum)
Purple leaves on transplants Usually indicates a Phosphorus Deficiency
Older leaves yellow, shrunken stems, dark near soil line; weak plants may wilt and die Rhizoctonia (Rhizoctonia spp.)
Black specks to larger spots on heads Downy mildew (Peronospora effusa)
Brown leaf tips May be a reaction to bright sun and heat (temperatures above 80° F.)
Split heads Too much water
Affecting Leaves:
Signs or Symptoms Cause
Small holes, shothole injury Flea beetles (Phyllotreta spp.)
Large hole in leaves; outer leaves riddled, excrement found at base of cabbage head Cabbage worms (Pieris rapaeor Cabbage looper

 

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Carrot

plant diagnostic_database

                                 Carrot (Daucus carota var. saliva)                          

Carrot        

Affected Area:

Plant Information:

Carrots are a cool season crop, hardy enough to be undisturbed by light frosts in the spring and fall.  A multitude of carrot cultivars exists; from short, stumpy cultivars adapted to more shallow soils, to long and thin cultivars requiring more exacting carrot growing conditions.  Carrots perform best in well-aerated, deep, loose sandy loam soils with a pH of 5.5-6.8.  Carrots require moderate to high levels of potassium and phosphorus, but only a moderate level of nitrogen.  An abundant and even water supply is necessary for good root development.  Misshapen carrots are more often a result of hard, compact soil than any pest problem.

 

Affecting Leaves:
Signs or Symptoms           Cause 
Yellow, dwarfed young leaves, bushy growth, purpled leaves Aster yellows (Phytoplasma) 
Yellow leaves, older first; stunted plants Nitrogen deficiency
Yellow-bronze, curled leaves; bushy top growth Aphids
Dark spots with yellow borders Cercospora leaf blight (Cercospora spp.) if younger leaves are affected. Alternaria leaf blight (Alternaria spp.) if older leaves are affected.
Seedlings clipped off at soil line Cutworms (Noctuidae spp.)
Poor seedling emergence Crusted soil; high temperatures
Affecting Roots:
Signs or Symptoms          Cause  
Roots chewed, meandering scars allon root with a rusty-red color Carrot rust fly (Psila rosae)
Yellow, stunted plants that wilt during bright, hot days and recover at night Usually a sign that roots are injured. Pull up plant and check roots for Wireworms or Root-knot nematodes (see below)
Small, irregular holes scattered over surface of root; Damage usually occurs later in the season and is worse in dry years. Wireworms
Bumps on roots and deformed carrots Root-knot nematodes (Meloidogyne spp.)
Jagged cracks, water-soaked appearance Freezing injury
Forked roots Can occur if soils are heavy, compacted, or stony; if root tips are injured; if roots are overcrowded.
Dark tunnels, often in a zig-zag pattern, on upper and outer part of root Carrot weevil (Otiorynchus spp.)
Internal cavity spot Calcium deficiency
Spindly, short roots Can be caused by potassium deficiency or excessive heat
Poor color and taste Caused by magnesium deficiency,phosphorus deficiency, low temperatures and excessive heat
Small, woody, hairy, pale roots Carrot yellows (Phytoplasma)
Green shoulders Exposure to sunlight



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Cauliflower

plant diagnostic_database

                                 Cauliflower (Brassica oleracea var. botrytis)                          

Cauliflower        

Affected Area:

Plant Information:

Cauliflower is a cabbage relative grown for its flowerbuds,which are clustered together in a head.  Cauliflower is not as cold tolerant, temperatures below 45 F can initiate flowering or bolting.  Cauliflower is a heavy feeder of nitrogen and phorphorus, requiring well-drained soils with a pH of 6.4 to 7.4.  Cauliflower has shallow roots requiring an abundance of water.  Do not grow cauliflower where any member of the cabbage family have grown in the past 3 years.  Set out transplants about the time of the last frost 18-24" apart in rows 3' apart.

 

Affecting Leaves:
Signs or Symptoms           Cause 
Roots are riddled with slimy, winding tunnels Cabbage root maggots
Affecting Roots:
Signs or Symptoms          Cause  
Yellow v-shaped spots on leaf margins with blackened veins Black rot (Xanthomonas campestris)
Yellowish leaves, lower leaves drop; stunted plants may have twisted stems, usually occurs soon after transplanting Fusarium yellows (Fusarium oxysporum)
Large hole in leaves; outer leaves riddled, excrement found at base of cabbage head Cabbage worms (Pieris rapaeor Cabbage looper
Small holes, shothole injury Flea beetles (Phyllotreta spp.)
Affecting Heads:
Signs or Symptoms          Cause  
Black specks or spots on heads Downy mildew (Peronospora effusa) 
Curds turn brown and appear watersoaked Boron deficiency or exposure of curds to bright sun and high temperatures 

 

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Celery

plant diagnostic_database

                                 Celery (Apium graveolens var. dulce)                          

Celery        

Affected Area:
  • Leaves and stalk


Plant Information:

Celery is a moisture-loving cool season crop, with heavy fertilizer requirements.  Celery prefers a pH of 6-7,with a generous amount of compost or well-rotted manure.  Celery seedlings are set out after night time temperatures are above 40 F.  If the temperture is to cold it may cause seed stalk formation.  Space plants 6-8" apart in rows 21/2' apart.  Keep plants moist but do not mound up dirt around plants as they may rot in warm weather.  Celery likes some shading in the heat of summer.

 

Affecting Leaves:
Signs or Symptoms           Cause 
Yellow, dwarfed young leaves, bushy growth, purpled leaves Aster yellows (Phytoplasma)
Yellow leaves, older first; stunted plants Nitrogen deficiency
Yellow leaves, reddish stalks Fusarium yellows (Fusarium oxysporum)
Yellow, curled leaves Aphids
Yellow, distorted new growth Tarnished plant bug (Lygus pratensis)
Mottled, yellow leaves, twisted stems, dwarfing Celery mosaic
Brown mottling of leaves, cross-wise cracks on stalks Boron deficiency
Discolored streaks on stalk Potassium deficiency
Rosetting of leaves Phosphorus deficiency
Blackening at center with death of growing points Calcium deficiency
Irregular yellow-brown leaf spots; sunken tan, elongated spots on stalks Cercospora leaf blight (Cercospora spp.)
Dwarfed, rotted plants Carrot rust fly (Psila rosae)
Chewed leaves Several worms including carrot (or celery) worm, Armyworm (Euxoa auxiliaris) , or Cabbage loopers

Chard

plant diagnostic_database

                                 Chard (Apium graveolens var. dulce)                          

Chard        

Affected Area:
  • Leaves

 

Plant Information:

Chard, better known as 'Swiss' chard is a type of beet developed for its green tops, which grow vigorously from late spring through to fall frost.  Chard prefers sandy, well-drained soil with a pH of 6.5-7.5.  To keep leaves tender, provide plenty of water and nitrogen.  The prominent central ribs may be cut away from the rest of the leaf to be cooked and served like asparagus.  The remainder of the leaf can be eaten as greens.

 

Affecting Leaves:
Signs or Symptoms           Cause 
Yellow leaves, older first; stunted plants Nitrogen deficiency
Yellow, curled leaves; stunted plants Aphids
Purplish patches on leaves Phosphorus deficiency
Brown leaf tips May be a reaction to bright sun and heat (temperatures above 80° F.)
Tan spots with dark borders Cercospora leaf spot (Cercospora spp.)
Yellow, rotted leaves; light-colored spots on upper leaf surface, white mildew on leaf undersides Downy mildew (Peronospora effusa)
Stunted, crinkled leaves Curly top
White or translucent, irregular tunnels in leaves Leafminers
Small holes, shot-hole injury Flea beetles (Phyllotreta spp.)
Chewed terminals and leaves Beet armyworm (Euxoa auxiliaris)

 

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Cherry

plant diagnostic_database

Stone Fruits:  Apricot, Cherry Chokecherry, Peach, Plum, etc.

(Prunus spp.) 

Prunus

Affected Area:

Plant Information:


The genus Prunus is comprised of nearly 200 species of five subgenera:  plums and apricots, almonds and peaches, umbellate cherries, deciduous racemose cherries, and the evergreen racemose cherries.  The species of this genus range from shrubs to trees over 90 ft. tall.  Over 100 species have been cultivated as either ornamentals or as food crops.  Trees for fruit production and many ornamentals are generally propagate by budding or grafting, while seed propagation is reserved for generation of rootstocks and breeding programs.  The most common rootstock:scion combinations are:  almond:almond and plum; apricot:apricot; mazzard cherry:sweet cherry; mahaleb cherry:sweet and sour cherry; peach:peach, almond, apricot, plum; American plum:plum in cold regions; Bessey cherry:dwarf peaches. 

 

Affecting Whole Plant:
Signs or Symptoms Cause 
Tree decline in vigor Phytophthora root rot (Phytophthoraspp.), Cytospora Canker (Valsa spp.,Leucostoma spp.), or Verticillium wilt(Verticillium spp.)
Affecting Leaves:
Signs or Symptoms Cause 
Leaves chewed, no associated webbing Pearslug (Caliroa derasi)
Upper surface of the leaf skeletonized Pearslug (Caliroa cerais) or Apple Thorn Skeletonizer
Webbing associated with chewing Fall webworm (Hyphantria cunea Drury),Ugly Nest caterpillar (Archips cerasivorana), or Western tent caterpillar(Malacosoma californicum)
Leaves with small, circular holes Shot hole disease 
White flecking injuries  White apple leafhopper (Typhlocyba pomaria McAtee) or Lacebug (Corythuca padi), on chokecherry (Corythuca spp.)
White powdery material on upper or lower surface of leaf Powdery mildew
Leaves yellow Iron chlorosis or X-disease
Leaves with small, pouch or finger-like projections Fingergall mites (Phytoptus species)
New leaves curled Aphids: Green peach aphid (Myzus persicae), Leafcurl plum aphid (Anuraphis helichrysi), or Black cherry aphid (Myzus cerasi)
New leaves curled and thickened and red/purple Peach leaf-curl disease
Affecting Larger Branches or Trunks:
Signs or Symptoms Cause 
Black galls on branches Black knot of cherry (Apiosporina morbosa) 
Stem decay and/or hoof-shaped fruiting body (conk) Decay fungus (Phellinus pomaceus)
Scales Scale: European fruit lecanium (Parthenolecanium corni) or Oystershell scale (Lepidosaphes ulmi)
Small pinhead-sized exit holes in branches Shothole borer (Scolytus rugulosus)
Branches die back Cytospora canker (Valsa spp.,Leucostoma spp.) or Shothole borer (Scolytus rugulosus)
Gumming and dark colored branches Shothole borer (Scolytus rugulosus), or Cytospora canker (Valsa spp.,Leucostoma spp.) or Bacterial Blight (Pseudomonas syringae)
Dead bark with discoloration and small pimple-like fruiting bodies (pycnidia) Cytospora canker (Valsa spp.,Leucostoma spp.)
Wilting and dieback of portions of tree, originating from roots Verticillium wilt (Verticillium spp.)
Affecting Ground Line Area of Trunk:
Signs or Symptoms Cause 
Discolored tissue under bark at ground line Phytophthora root rot (Phytopthora sp.)
Gall at ground line Crown gall (Agrobacterium tumefaciens)
Affecting Fruit:
Signs or Symptoms Cause 
Fruit tunneled European earwig (Forficula auricularia L.)
Fruit with sunken, corky areas Plant bug (Lygus species), Hail injury, or Boxelder bug (Boisea trivittata)
Puncture wounds in fruit Bird damage (Robins, finches, etc.)
Chokecherry fruit enlarged, hollow Chokecherry gall midge (Contarinia virginianae)
Maggots in cherry fruit Western cherry fruit fly (Rhagoletis indifferens Curran

 

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Cherry (2)

plant diagnostic_database

Stone Fruits:  Apricot, Cherry Chokecherry, Peach, Plum, etc.

(Malus spp.) 

Prunus

 

 

Affected Area:

 

 

  

Affecting Whole Plant:
Signs or Symptoms Cause 
Tree decline in vigor Phytophthora root rot (Phytophthoraspp.), Cytospora Canker (Valsa spp.,Leucostoma spp.), or Verticillium wilt(Verticillium spp.

 

Plant Information:


The genus Prunus is comprised of nearly 200 species of five subgenera:  plums and apricots, almonds and peaches, umbellate cherries, deciduous racemose cherries, and the evergreen racemose cherries.  The species of this genus range from shrubs to trees over 90 ft. tall.  Over 100 species have been cultivated as either ornamentals or as food crops.  Trees for fruit production and many ornamentals are generally propagate by budding or grafting, while seed propagation is reserved for generation of rootstocks and breeding programs.  The most common rootstock:scion combinations are:  almond:almond and plum; apricot:apricot; mazzard cherry:sweet cherry; mahaleb cherry:sweet and sour cherry; peach:peach, almond, apricot, plum; American plum:plum in cold regions; Bessey cherry:dwarf peaches. 

 

Affecting Whole Plant:
Signs or Symptoms Cause 
Tree decline in vigor Phytophthora root rot (Phytophthoraspp.), Cytospora Canker (Valsa spp.,Leucostoma spp.), or Verticillium wilt(Verticillium spp.)
Affecting Leaves:
Signs or Symptoms Cause 
Leaves chewed, no associated webbing Pearslug (Caliroa derasi)
Upper surface of the leaf skeletonized Pearslug (Caliroa cerais) or Apple Thorn Skeletonizer
Webbing associated with chewing Fall webworm (Hyphantria cunea Drury),Ugly Nest caterpillar (Archips cerasivorana), or Western tent caterpillar(Malacosoma californicum)
Leaves with small, circular holes Shot hole disease 
White flecking injuries  White apple leafhopper (Typhlocyba pomaria McAtee) or Lacebug (Corythuca padi), on chokecherry (Corythuca spp.)
White powdery material on upper or lower surface of leaf Powdery mildew
Leaves yellow Iron chlorosis or X-disease
Leaves with small, pouch or finger-like projections Fingergall mites (Phytoptus species)
New leaves curled Aphids: Green peach aphid (Myzus persicae), Leafcurl plum aphid (Anuraphis helichrysi), or Black cherry aphid (Myzus cerasi)
New leaves curled and thickened and red/purple Peach leaf-curl disease
Affecting Larger Branches or Trunks:
Signs or Symptoms Cause 
Black galls on branches Black knot of cherry (Apiosporina morbosa) 
Stem decay and/or hoof-shaped fruiting body (conk) Decay fungus (Phellinus pomaceus)
Scales Scale: European fruit lecanium (Parthenolecanium corni) or Oystershell scale (Lepidosaphes ulmi)
Small pinhead-sized exit holes in branches Shothole borer (Scolytus rugulosus)
Branches die back Cytospora canker (Valsa spp.,Leucostoma spp.) or Shothole borer (Scolytus rugulosus)
Gumming and dark colored branches Shothole borer (Scolytus rugulosus), orCytospora canker (Valsa spp.,Leucostoma spp.) orBacterial Blight (Pseudomonas syringae)
Dead bark with discoloration and small pimple-like fruiting bodies (pycnidia) Cytospora canker (Valsa spp.,Leucostoma spp.)
Wilting and dieback of portions of tree, originating from roots Verticillium wilt (Verticillium spp.)
Affecting Ground Line Area of Trunk:
Signs or Symptoms Cause 
Discolored tissue under bark at ground line Phytophthora root rot (Phytopthora sp.)
Gall at ground line Crown gall (Agrobacterium tumefaciens)
Affecting Fruit:
Signs or Symptoms Cause 
Fruit tunneled European earwig (Forficula auricularia L.)
Fruit with sunken, corky areas Plant bug (Lygus species), Hail injury, orBoxelder bug (Boisea trivittata)
Puncture wounds in fruit Bird damage (Robins, finches, etc.)
Chokecherry fruit enlarged, hollow Chokecherry gall midge (Contarinia virginianae)
Maggots in cherry fruit Western cherry fruit fly (Rhagoletis indifferens Curran

 

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Chokecherry

plant diagnostic_database

Stone Fruits:  Apricot, Cherry Chokecherry, Peach, Plum, etc.

(Prunus spp.) 

Prunus

Affected Area:

Plant Information:


The genus Prunus is comprised of nearly 200 species of five subgenera:  plums and apricots, almonds and peaches, umbellate cherries, deciduous racemose cherries, and the evergreen racemose cherries.  The species of this genus range from shrubs to trees over 90 ft. tall.  Over 100 species have been cultivated as either ornamentals or as food crops.  Trees for fruit production and many ornamentals are generally propagate by budding or grafting, while seed propagation is reserved for generation of rootstocks and breeding programs.  The most common rootstock:scion combinations are:  almond:almond and plum; apricot:apricot; mazzard cherry:sweet cherry; mahaleb cherry:sweet and sour cherry; peach:peach, almond, apricot, plum; American plum:plum in cold regions; Bessey cherry:dwarf peaches. 

 

Affecting Whole Plant:
Signs or Symptoms Cause 
Tree decline in vigor Phytophthora root rot (Phytophthoraspp.), Cytospora Canker (Valsa spp.,Leucostoma spp.), or Verticillium wilt(Verticillium spp.)
Affecting Leaves:
Signs or Symptoms Cause 
Leaves chewed, no associated webbing Pearslug (Caliroa derasi)
Upper surface of the leaf skeletonized Pearslug (Caliroa cerais) or Apple Thorn Skeletonizer
Webbing associated with chewing Fall webworm (Hyphantria cunea Drury),Ugly Nest caterpillar (Archips cerasivorana), or Western tent caterpillar(Malacosoma californicum)
Leaves with small, circular holes Shot hole disease 
White flecking injuries  White apple leafhopper (Typhlocyba pomaria McAtee) or Lacebug (Corythuca padi), on chokecherry (Corythuca spp.)
White powdery material on upper or lower surface of leaf Powdery mildew
Leaves yellow Iron chlorosis or X-disease
Leaves with small, pouch or finger-like projections Fingergall mites (Phytoptus species)
New leaves curled Aphids: Green peach aphid (Myzus persicae), Leafcurl plum aphid (Anuraphis helichrysi), or Black cherry aphid (Myzus cerasi)
New leaves curled and thickened and red/purple Peach leaf-curl disease
Affecting Larger Branches or Trunks:
Signs or Symptoms Cause 
Black galls on branches Black knot of cherry (Apiosporina morbosa) 
Stem decay and/or hoof-shaped fruiting body (conk) Decay fungus (Phellinus pomaceus)
Scales Scale: European fruit lecanium (Parthenolecanium corni) or Oystershell scale (Lepidosaphes ulmi)
Small pinhead-sized exit holes in branches Shothole borer (Scolytus rugulosus)
Branches die back Cytospora canker (Valsa spp.,Leucostoma spp.) or Shothole borer (Scolytus rugulosus)
Gumming and dark colored branches Shothole borer (Scolytus rugulosus), or Cytospora canker (Valsa spp.,Leucostoma spp.) or Bacterial Blight (Pseudomonas syringae)
Dead bark with discoloration and small pimple-like fruiting bodies (pycnidia) Cytospora canker (Valsa spp.,Leucostoma spp.)
Wilting and dieback of portions of tree, originating from roots Verticillium wilt (Verticillium spp.)
Affecting Ground Line Area of Trunk:
Signs or Symptoms Cause 
Discolored tissue under bark at ground line Phytophthora root rot (Phytopthora sp.)
Gall at ground line Crown gall (Agrobacterium tumefaciens)
Affecting Fruit:
Signs or Symptoms Cause 
Fruit tunneled European earwig (Forficula auricularia L.)
Fruit with sunken, corky areas Plant bug (Lygus species), Hail injury, or Boxelder bug (Boisea trivittata)
Puncture wounds in fruit Bird damage (Robins, finches, etc.)
Chokecherry fruit enlarged, hollow Chokecherry gall midge (Contarinia virginianae)
Maggots in cherry fruit Western cherry fruit fly (Rhagoletis indifferens Curran

 

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Corn

 

 

plant diagnostic_database

                                 Corn (Zea mays var. saccharata)                          

Corn        

Affected Area:

Plant Information:

Sweet corn is challenging to grow, but is well worth the fresh picked rewards.  It loses sweetness soon after picking.  Temperature and moisture are vital to growing corn.  Plant corn when soil temperatures are > 50 F, with rich light soils in a pH range of 6-7.  Corn is a very heavy feeder and does well with compost worked into the soil before planting and side dressing of nitrogen rich fertilizer when its 12" tall and when it begins to silk.  Plant corn in four rows so it is easily pollinated by the wind.  Irrigate corn consistantly and well, especially when plants are young.  Corn kernals can be white, bicolor or yellow.  Cultivar groups are classified as normal sugary, sugar enhanced, and supersweet.  Supersweet cultivars must be isolated by 25' from all other sweet corn or cross-pollination may result in starchy, tough kernels.  Warming the soil before planting with clear plastic will increase germination.

 

Affecting Seed, seedling, and whole plant:
Signs or Symptoms      Cause
Wilted, stunted plants and/or spotty, poor stands May be due to several soil-dwelling pests including: WirewormSeed corn maggots, or, less commonly, white grubs
Wilting, stunting, and poor germination Corn root worms
Affecting Leaves:
Signs or Symptoms Cause
Numerous small holes, bleached out spots or stripes on leaves Flea beetles(Phyllotreta spp.)
Ragged leaf margins on young plants; plants cut at base of stem Cutworms (Noctuidae spp.)
Holes in leaves, shot-hole leaf injury Corn earworm (Heliothis zea ) , European corn borer (Ostrinia nubilalis) , or Armyworm (Euxoa auxiliaris)
Round, brown raised spots on leaves Rust
Mottled, stunted new leaves; poor kernel formation at base of ear Maize dwarf mosaic virus
White-black, puffed-out growths on ears, tassels, and stems Smut (Ustilago maydis)
Older leaves purple on young plants Phosphorus deficiency
Yellow leaves, older first; stunted plants Nitrogen deficiency
Yellow, curled leaves; stunted plants Aphids
Affecting Ears:
Signs or Symptoms           Cause 
Irregular ears with corky bands at the base of kernels Boron deficiency, phosphorus deficiency, or potassium deficiency
Large, chewed areas or dry, brown exposed kernels at the top of ear Birds
Hollowed-out kernels in the upper half of the ear Sap Beetles
Damage to developing kernels at ear tips Corn earworm
Bored ears and stalks, with damage seen anywhere on ear (not just at tips) European corn borers (Ostrinia nubilalis) and/or Armyworms (Euxoa auxiliaris)

 

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Cottonwood

plant diagnostic_database

                                Cottonwood (Populus spp., except Aspen)                          

Populus spp.        

Affected Area:

Plant Information:

Populus 

Cottonwood trees are all known for rapid growth. They grow best with regular deep watering, ensuring roots grow deeply to become drought tolerant.  Do not plant near water lines or sewers as their roots are invasive.  There are 30-35 species of poplars and numerous hybrids and named cultivars.  Cottonwoods are commonly used in windbreak and fence row plantings. 

 

Affecting Leaves:
Signs or Symptoms           Cause 
Leaves chewed Cottonwood leaf beetle (Chrysomela scripta), Spiny elm caterpillar (Nymphalis antiopa), Fall webworm (Hyphantria cunea), or Tussock moth (Dasychira vagans)
Webbing/Tents produced Fall webworm (Hyphantria canea),Western tent caterpillar (Malacosoma californicum), or Forest tent caterpillar(Malacosoma disstria)
Small holes chewed in leaves Flea beetles (Chrysomelidae)
Leaves tunneled Aspen leafminer (Phyllocnistis populiella)
Leaves spotted with young leaves blackened Shoot blight(Venturia populina) or Frost injury
Black spots with yellow margins Marssonina blight (Marssonina populi)
Black, irregular spots Septoria leaf spot and canker (Septoria popolicole)
Blackish-brown round spot, which drops out of leaf, leaving shothole-like appearance Ink spot (Ciborinia whetzelii)
Rust to orange colored spots Conifer-aspen rust (Melampsora spp.)
Yellowed leaves Root damage caused by under or over watering, or Iron chlorosis
White powdery material on upper or lower surface of leaves Powdery mildew (Erysiphe cichoracerum)
Leaf petioles, veins with swelling Petiole-gall aphids (Pemphigus spp.)
Leaves generally distorted and thickened Poplar vagabond aphid (Mordwilkoja vagabunda)
Affecting Stems, Twigs or Small Branches:
Signs or Symptoms Cause
Hollow swellings on new shoots Petiole-gall aphids (Pemphigus spp.)
Terminal leaves distorted into thickened mass Poplar vagabond aphid(Mordwilkoja vagabunda)
Twigs shredded in irregular row Cicada oviposition injury (Platypeisidae)
Swellings in twigs, small branches Poplar gall borer (Superda inornata) or Hail injury (upper surface only)
Scales on twigs, branches Oystershell scale (Lepidosophes ulmi)
Catkins grossly distorted and enlarged Cottonwood catkin gall mite (Eriophyes neoessigi)
Affecting Larger Branches or Trunks:
Signs or Symptoms                                Cause
Fungal fruiting bodies (mushrooms, conks) present Stem decay fungi (various species)
Open wounds, internal decay, swollen areas in stem  Stem decay fungi (various species)
Masses of caterpillars resting on bark Forest tent caterpillar (Malacosoma disstria)
Tunneling in trunk, often with orange staining ooze Cottonwood borer (Plectodera scalator),Poplar borer (Saperda calcarata),Cottonwood Crown Borer, or American hornet moth (Sesia tibialis)
Clear to white oozing or frothy malodorous liquid exiting from wounds Bacterial wetwood/slime flux
Areas of dead bark with discoloration and small pimple-like fruiting bodies (pycnidia) Cytospora canker (Valsa spp.,Leucostoma spp.)
Insects visiting oozing sap from trunk Flies (various families)
Affecting Roots and Ground Line Area:
Signs or Symptoms:                                          Cause:                                                                                                      
White root decay with white mycelial fans between bark and wood Armillaria root disease (Armillaria mellea)
Gall at ground line Crown gall (Agrobacterium tumefaciens)

 

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Crabapple

plant diagnostic_database

Apple, Crabapple (Malus spp.) 

 

malus

Affected Area:

Plant Information:

Members of the Rosaceae family that are deciduous trees, rarely shrubs.  Flowers that can be white, pink or red and fruit which is edible, showy or sometimes both.  Most are between 10-30' in height.   Good well drained soils are best but will tolerate some clay and wet soils.  Most are hardy to zones 4-7 and should be planted in full sun for best development of flowers and fruit. There are over 700 varieties of crabapples and 7500 of apples nationwide.   Most are propagated by budding, grafting from softwood cuttings or tissue culture.

 

  • USDA Plants Database
  • Lady Bird Johnson Wildflower Center
  • Elisabeth Miller Library
  • Oregon State University Landscape Plants
Affecting Leaves:
Signs or Symptoms Cause 
Large holes chewed in leaves Speckled green fruitworm, Redhumped caterpillar (Schizura concinna) , or Forest tent caterpillar.
Silken tents produced Western tent caterpillar or Fall webworm(Hyphantria cunea)
Caterpillar living within a case Snailcase bagworm (Apterona helix)
Terminal leaves curled and tied together with silk Fruittree leafroller or Obliquebanded leafroller 
Skeletonized leaves Apple and thorn skeletonizer (Choreutis pariana) or Apple flea beetle (Phyllotretaspp.)
"Shothole" feeding wounds in leaf, usually with sucker growth Apple flea beetle (Phyllotreta spp.)
Raised leafmines Western tentiform leafminer
(Phyllonorycter elmaella)
White powdery material on upper or lower surface of leaf Powdery mildew
Pale green or yellow leaves Iron chlorosis. See Nutrient Deficiencies
Rust orange spots Juniper rusts
Black mold on surface of leaf Apple scab (Venturia inaequalis)
Rusty blisters or scabby patches on leaves Blister mites. See Eriophyid Mites
Bronzing of leaves Two-spotted spidermite or McDaniel spider mite
Curling distortions of new growth in spring Rosy apple aphid
Blackened and wilted leaves Fireblight (Erwinia amylovora)
Affecting Stems, Twigs or Small Branches:
Signs or Symptoms Cause
Twigs shredded by a line of multiple punctures Cicada oviposition wounds
Blackened, wilting, and crooked tips Fireblight (Erwinia amylovora)
Black beetle tunneling, with small exit holes Shothole borer
Scales on twigs Oystershell scale or European fruit lecnium
Cottony insects on twigs Woolly apple aphid or Mealbugs
Discolored areas, dead bark containing small pimple-like fruiting bodies (pycnidia) Cytospora canker (Valsa spp.,Leucostoma spp.)

 

Affecting Larger Branches or Trunks:
Signs or Symptoms Cause
Boring into trunk Flatheaded appletree borer - (Chrysobothris mali)
Bark beetle tunneling, small exit holes Shothole borer
Cottony insects on trunk and/or roots Woolly apple aphid
Internal decay and/or shelf-like fruiting structures (conks) Decay fungus
Wilting and dieback of portions of tree, originating from roots Verticillium wilt (Verticillium spp.)
Affecting Ground Line Area of Trunk:
Signs or Symptoms Cause
Discolored tissue under bark at ground line Phytophthora root rot (Phytophthoraspp.)
Galls at ground line  Crown gall
Affecting Roots:
Signs or Symptoms Cause
White root decay and white mycelial fans between bark and wood Armillaria root disease (Armillaria spp.)

 

Affecting Fruit:
Signs or Symptoms Cause
Tunneling in fruit Codling moth (Cydia pomonella)
Scarring or scabbing of fruit Fruittree leafroller, Hail injury, or Apple scab (Venturia inaequalis)
Pitted, scarred fruit Tarnished Plant Bug (Lygus lineolaris)

 

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Cucumber

 

 

plant diagnostic_database

                               Cucumber (Cucumis sativus)                          

Cucumber        

Affected Area:

Plant Information:

Cucumbers are members of the cucurbit family, which are a warm weather, sun requiring vegetable.  Types of cucumbers include long, smooth, green slicing types; small pickling types; and roundish, yellow, mild-flavored lemon cucumbers.  Novelties include oriental(long, slim, very mild), Armenian(actually long, curving, pale green, ribbed melon with cucumber look and mild flavor) and English.

Cucumbers grow best in soils with a pH of 5.5-7.0 and 60°F.  Set transplants out or plant seeds when all danger of frost is past.  In small gardens they can be trained to climb a fence.  Provide plenty of moisture and harvest fruits while they are dark green, if they turn yellow the plant quits producing.

 

 

Affecting Leaves and Vines:
Signs or Symptoms      Cause
Plants wilt, foliage looks burned; preceded by pale green areas forming on leaves Squash bug (Anasa tristus)
Sudden wilting of a runner or part of a runner Squash vine borer (Melitta satyriniformis)
Leaves wilt, yellow, and curl High Aphid populations
Vines wilt and die gradually, starting with newer leaves; no leaf yellowing is present Bacterial wilt (Erwinia tracheiphila)
Small, pitted leaf holes on young plants Cucumber beetles (Acalymma vittata)
Distorted, Yellow spots on leaves with mottling and wrinkling of older leaves Mosaic viruses
Older leaves mottled yellow between veins Downy mildew (Peronospora effusa)
Powdery, white spots on upper surface of leaves especially Powdery mildew
Leaf spots that begin as water-soaked, then turn gray, die and drop out leaving foliage with a shot-hole appearance Angular leafspot (Pseudomonas syringae)
If water-soaked, yellow spots turn brown Anthracnose
Affecting Fruit:
Signs or Symptoms Cause
Small, brown, angular fruit spots Angular leafspot (Pseudomonas syringae)
Brown and sunken zoned spots Alternaria (Alternaria spp.)
Circular, black, sunken cankers Anthracnose
Misshapen, yellow mottled fruit, often with a bitter taste Mosaic virus
Fruit wilts and shrivels Bacterial wilt (Erwinia tracheiphila)
Fruit is narrow at stem end Potassium deficiency
Fruit has a dull bronze color Phosphorus deficiency
Fruit is light colored Nitrogen deficiency
Dark pitting of fruit Cold damage


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Currant

 

 

plant diagnostic_database

                                Currant or Gooseberry (Ribes spp.)                          

Currant        

Affected Area:

Plant Information:

Currants and Gooseberries belonging to the Ribes species, are a multi-stem shrub grown for their fruit used for pies, preserves or sauces.  Yellowish flowers are in drooping clusters are formed in the spring followed by  red or white fruit in summer.  They are easily grown; tolerant of any good soil; full sun to light shade. Their height ranges within the varieties from 4-8'.  Propagate from softwood cuttings taken in June-July.

 

Affecting Leaves:
Signs or Symptoms      Cause
White flecks in leaves Rose leafhoppers (Edwardsiana rosae) orTwospotted spider mite
White powdery material on upper or lower surface of leaf Powdery mildew (Mycosphaerella sp.)
Leaves puckered, often thickened and discolored Currant aphid (Amphorophora agathonica Hottes or Cryptomyzus ribis)
Leaves chewed Imported currantworm (Nematus ribesi) or Western tent caterpillar (Malacosoma californicum)
Hollow swelling in leaves Gall-making sawfly
Orange to yellow colored spots on underside of leaf Leaf rusts (various species)
Affecting Twigs and Smaller Branches:
Signs or Symptoms Cause
Tunneling in stems or branches Current borer (Synanthedon tipuliformis) or Bronze cane borer (Agrilus aurichaleceus)
Affecting Fruit:
Signs or Symptoms Cause
Maggot in fruit Currant fruit fly (Epochra canadensis)


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Dogwood

 

 

plant diagnostic_database

                               Dogwood (Cornus spp.)                          

Cornus        

Affected Area:

Plant Information:

 

Dogwoods are deciduous trees and shrubs preferring a moist well drained soil in full sun or shade.  Some varieties can grow to 20 in height.  Dogwoods have a fibrous root system and grows rapidly.  Some cultivars have yellow or red twigs adding landscape interest in the winter months.  Propagation by seed or softwood cuttings.  Some species are used as hedges, for erosion control and the fruit is utilized by wildlife.

 

 

Affecting Leaves:
Signs or Symptoms      Cause
Leaves chewed Redhumped caterpillar (Schizura concinna)
New leaves curled Sunflower aphid (Aphis helianthi)
Black spots on leaves Septoria leaf spot and canker (Septoria cornicola)
White powdery material on upper or lower surface of leaf Powdery mildew
Affecting Twigs and Smaller Branches:
Signs or Symptoms Cause
Scales Oystershell scale (Lepidosaphes ulmi)
Dead areas on stem Nectria canker (Nectria sp.) or Root collar rot (Phytophthora sp.)
Affecting Fruit:
Signs or Symptoms Cause
Feeding in or on berries Conifer seed bugs (Leptoglossus occidentalis)


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Douglas Fir

 

 

plant diagnostic_database

                              Douglas Fir (Pseudostuga menziesii)                          

Pseudotsuga        

Affected Area:

Plant Information:

 

Douglas fir have a sharply pyramidal form when young; widely grown and cherished as a Christmas tree.  Grows 70-130'  height with densely set, soft dark green or blue-green needles 1-1½" long, radiating out in all directions from twigs and branches.  Sweet fragrance when crushed.  Reddish brown cones are oval, about 3" long, and have obvious pronged bracts, that hang down.  Douglas fir prefers neutral to slightly acid, well drained moist soils.  At one time the most important lumber tree in the US.

 

 

http://plants.usda.gov/plantguide/pdf/cs_psme.pdf 

Affecting Buds:
Signs or Symptoms      Cause
Buds tunneled Western spruce budworm (Choristoneura occidentalis)
Affecting Needles:
Signs or Symptoms Cause
Newer needles being chewed Douglas-fir tussock moth (Orgyia pseudotsugata) or Western spruce budworm (Choristoneura occidentalis)
Needles with discolored spotting, various color spots Needle casts (various fungi)
Needles with discolored spotting, rust or orange color spots Conifer aspen rust (Melampsora spp.)
Needles to exterior of tree bleached or brown, developing late winter Winter dessication
Brown felt-like materials on needles or branches (high elevations) Brown felt blight (Herpotricha juniperi)
Needles bent, twisted Cooley spruce gall adelgid (Adelges cooleyi) or Frost injury
Woolly aphids on needles Cooley spruce gall adelgid (Adelges cooleyi)
Whole tree fades, reddens Douglas-fir beetle (Dendroctonus pseudotsugae)
Affecting Cones:
Signs or Symptoms Cause
Flowers tunneled Western spruce budworm (Choristoneura occidentalis)
Woolly aphids on cones Cooley spruce gall adelgid (Adelges cooleyi)
Sucking on developing cones Conifer seed bugs (Leptoglossus occidentalis)
Affecting Trunk or Larger Branches:
Signs or Symptoms Cause
Witches’ brooms on branches, small shoots emerging from branch Dwarf mistletoe
Large galls Bacteria-like gall or Burl
Aphids Giant conifer aphids (Cinara spp.)
Tunneling in trunk, branches Douglas-fir beetle (Dendroctonus pseudotsugae)
Open wounds, internal decay, swollen areas in stem Stem decay fungi (Fomitopsis pincola,Cryptoporus volvatus and various fungal genera)
Affecting Roots:
Signs or Symptoms Cause
White root decay with white mycelial fans between bark and wood Armillaria root disease (Armillaria mellea)


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Eggplant

 

 

plant diagnostic_database

                             Eggplant (Solanum melongena var. esculentum)                          

Eggplant        

Affected Area:

Plant Information:

 

Eggplants, widely grown as a meat substitute in the Mediterranean region, are less common here because they require very warm weather - optimum growing temperatures of 70-85°.  Eggplants come in various shapes from thin and long to short and blocky, and colors, white to purple.  The plants grow 2 to 3 feet tall, with each plant bearing four or more fruits.

Eggplants prefer well-drained, fertile sandy loams, high in organic matter.  Eggplants require more nitrogen than tomatoes, with moderate amounts of phosphorus and potassium.  Eggplant does best at a pH of 6.0-6.8, but will tolerate a pH as low as 5.5.  Eggplants have a high moisture requirement.  Set out plants when night temperatures are above 55°, 2½ feet apart.  They will perform better with a plastic mulch to hold in heat and moisture.  Pick all fruit before they mature; otherwise they will stop producing.

 

Affecting Leaves:
Signs or Symptoms      Cause
Large holes in leaves, skeletonized leaves; plants and leaflets stripped Colorado potato beetle (Leptinotarsa decemlineata)
Tiny, pitted holes in leaves, leaves may have a lacelike appearance and turn dull, dry green Flea beetle (Phyllotreta spp.)
Yellow leaves turn brown and die Lacebug
Yellow leaves accompanied by gradual wilting and browning between leaf veins Verticillium wilt (Verticillium spp.)
Yellow mottling of leaves; curling and malformation of leaves Tobacco mosaic virus or cucumber mosaic virus
Circular, dark spots on leaves Alternaria Leaf Blight
Large holes in leaves Grasshoppers (Melanoplus spp.)
Affecting Fruit:
Signs or Symptoms Cause
Dry, brown chew marks Colorado potato beetle (Leptinotarsa decemlineata)


 
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Elm

 

 

plant diagnostic_database

                             Elm (Ulmus spp.)                          

Ulmus        

Affected Area:

Plant Information:

Deciduous fast growing trees easily grown in most soils.  Best with normal watering, but will tolerate low moisture conditions at expense of good growth, plant health.  Root systems are aggressive and close to surface.  Branch crotches often narrow, easily split.

The elms are subject to many pests, which are fatal and control measures are not effective or available.  Elms were once used extensively as street and lawn trees.  The American elm was overplanted and when Dutch elm disease struck it devastated the elm populations.  The species of elms grow between 50-100' tall.  Some species have a weedy nature with their papery winged seedpods dispersing over a wide area.  Once used in windbreaks and shelterbelts, new cultivars have been developed for resistance to Dutch Elm disease.

 

 http://plants.usda.gov/java/profile?symbol=ULMUS

Affecting Leaves:
Signs or Symptoms      Cause
Leaves skeletonized, primarily on leaf underside Elm leaf beetle (larvae) (Xanthogaleruca luteola)
Holes chewed through leaves Elm leaf beetle (Xanthogaleruca luteola)
Leaves irregularly chewed Spiny elm caterpillar (Nymphalis antiopa);Fruittree leafroller (Archips argyrospila),Forest tent caterpillar (Malacosoma disstria), or Fall webworm (Hyphantria cunea)
Masses of dark, spiny caterpillars on leaves  Spiny Elm Caterpillar - Morning Cloak Butterfly (Nymphalis antiopa) - No significant damage.
New leaves small, twisted Eriophyid mites (Eriophyidae) or Phenoxy herbicide injury. See Chemical Injury
Leaves curled, thickened Woolly aphids (Eriosoma spp.)
Leaves with white flecks Leafhoppers (Erythroneura spp.)
Pale green or yellow leaves Iron chlorosis
Sucking insects on leaves, often with associated honeydew European elm scale (Gossyparia spurai) or Elm leaf aphid (Myzocallis ulmifolii)
Yellowing, wilting foliage Scale "flagging" - European elm scaleDutch elm disease (Ophiostoma ulmi), or Verticillium wilt (Verticillium spp.)
Affecting Twigs and Smaller Branches:
Signs or Symptoms Cause
Scales European fruit lecanium(Parthenolecanium corni) or European elm scale (Gossyparia spuria)
Affecting Larger Branches or Trunk:
Signs or Symptoms Cause
Borers Elm borer (Saperda tridentata Oliver) or Flatheaded appletree borer(Chrysobothris femorata)
Areas of dead bark With discoloration and small pimple-like fruiting bodies (pycnidia) Cytospora canker (Valsa spp.,Leucostoma spp.)
Open wounds, internal decay, or swollen areas on stem Stem decay fungi (Collybia velutipes,Phellinus igniarius and various genera)
Fungal fruiting bodies (mushrooms, conks) present Stem decay fungi (Collybia velutipes, Phellinus igniarius and various genera)
Clear to white oozing or frothy malodorous liquid exiting from wounds Bacterial wetwood / slime flux


 
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Euonymus

 

 

plant diagnostic_database

                               Euonymus (Euonymus spp.)                          

Euonymus        

Affected Area:
  • Leaves
  • Roots and ground line area

Plant Information:

 

Euonymus are evergreen or deciduous shrubs that are valued for their foliage, texture and form.  Many uses as a landscape plant in hedges, specimen and border plantings.  It's interesting foliage color and interesting stem character are best seen when planted in full sun to light shade.  Requires only moderate watering after establishment.  The best growth is seen in well-drained soils, is pH adaptable, with a fibrous root system.  Easily propagated from seeds.

 

 

http://www.clemson.edu/extension/hgic/plants

/landscape/shrubs/hgic1063.html 

 

Affecting Leaves:
Signs or Symptoms      Cause
Notches cut in edge of leaves Black vine weevil (Otiorhynchus sulcatus)
Leaves mined, edges curled with webbing Lilac leafminer (Caloptilia syringella)
New leaves curled, thickened Bean aphids (Aphis fabae)
Flecking, discoloration Twospotted spider mite (Tetranychus urticae Koch)
Affecting Roots and Ground Line Area:
Signs or Symptoms Cause
Chewing of roots Black vine weevil (Otiorhynehus sulcatus)


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Fir

 

 

plant diagnostic_database

                              Fir (Abies spp.)                          

Abies lasiocarpa        

Affected Area:

Plant Information:

 

Firs are evergreen trees in nature that are tall, erect, symmetrical with uniformly spaced branch whorls.  The needlelike leaves are linear, long flattened and blunt-tipped.  Female seed cones produced erect at the tips of last season's growth.  Firs are slow growing especially when planted outside their native habitats.  Firs require moist, well drained acidic soils and high atmospheric moisture with cooler temperatures.  There are many landscape cultivars among the various species including prostrate, compact, pendulous, contorted, fastigiate, yellow-foliaged and blue-foliaged types.  Native to Montana are the grand and subalpine firs.

 

 

http://plants.usda.gov/plantguide/pdf/pg_abgr.pdf

Affecting Buds:
Signs or Symptoms      Cause
Buds tunneled Western Spruce budworm (Choristoneura occidentalis)
Affecting Needles:
Signs or Symptoms Cause
New needles being chewed Douglas-fir tussock moth (Orgyia pseudotsugata) or Western spruce budworm (Choristoneura occidentalis)
Needles to exterior of tree bleached or brown, developing late winter Winter dessication
Various colored spots Needlecast diseases
Orange colored pustules on needles Fir broom rust (Melampsorella caryophyllacearum)
Brown felt-like material on needles, branches Brown felt blight (Herpotrichia juniperi)
Needles being mined White fir needleminer (Epinotia meritana)
Aphids on needles Giant conifer aphids (Cinara spp.)
Affecting Twigs and Smaller Branches:
Signs or Symptoms Cause
Large aphids on branches, twigs Giant conifer aphids (Cinara spp.)
Affecting Larger Branches or Trunk:
Signs or Symptoms Cause
Bark beetles Fir engraver (Scolytus ventralis Le Conte)
Borers Flatheaded fir borer (Melanophila drummondi)
Witches brooms on branches, orange to yellow colored pustules on needles Fir broom rust (Melampsorella caryophyllacearum)
Large aphids on branches or trunk Giant conifer aphids (Cinara spp.)
Fungal fruiting bodies (mushroom, conks) present Stem decay fungi (various species)
Open wounds, internal decay, swollen areas in stem Stem decay fungi (various species)
Affecting Roots and Ground Line Area:
Signs or Symptoms Cause
White root decay with white mycelial fans between bark and wood Armillaria root disease (Armillaria mellea)


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Gooseberry

 

 

plant diagnostic_database

                                Currant or Gooseberry (Ribes spp.)                          

Currant        

Affected Area:

Plant Information:

Currants and Gooseberries belonging to the Ribes species, are a multi-stem shrub grown for their fruit used for pies, preserves or sauces.  Yellowish flowers are in drooping clusters are formed in the spring followed by  red or white fruit in summer.  They are easily grown; tolerant of any good soil; full sun to light shade. Their height ranges within the varieties from 4-8'.  Propagate from softwood cuttings taken in June-July.

 

Affecting Leaves:
Signs or Symptoms      Cause
White flecks in leaves Rose leafhoppers (Edwardsiana rosae) orTwospotted spider mite
White powdery material on upper or lower surface of leaf Powdery mildew (Mycosphaerella sp.)
Leaves puckered, often thickened and discolored Currant aphid (Amphorophora agathonica Hottes or Cryptomyzus ribis)
Leaves chewed Imported currantworm (Nematus ribesi) or Western tent caterpillar (Malacosoma californicum)
Hollow swelling in leaves Gall-making sawfly
Orange to yellow colored spots on underside of leaf Leaf rusts (various species)
Affecting Twigs and Smaller Branches:
Signs or Symptoms Cause
Tunneling in stems or branches Current borer (Synanthedon tipuliformis) or Bronze cane borer (Agrilus aurichaleceus)
Affecting Fruit:
Signs or Symptoms Cause
Maggot in fruit Currant fruit fly (Epochra canadensis)


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Hackberry

plant diagnostic_database

                                Hackberry (Celtis spp.)                          

Celtis        

Affected Area:
  • Leaves                                                                   


                                                       

Plant Information:

 

Hackberrys are in the Ulmaceae family as are elms.  Hackberry tolerates a wide variety of soils and moisture conditions.  Common hackberry grows to form a 50' tall and wide canopy with 2-5" bright green, finely toothed leaves.  The older bark forms narrow corky projecting ridges which are sometimes reduced to wart like projections.  A good tree for park and large area use.

 

 

Affecting Leaves:
Signs or Symptoms           Cause 
Leaves being chewed Fruittree leafroller (Archips argyrospila) or Spiny elm caterpillar, usually in masses (Nymphalis antiopa)
Leaves with white flecking (net-leaf hackberry) Lacebugs (Corythucha spp.)
Leaves yellowed Iron chlorosis or other deficiency, or Root damage from under or over watering
Leaves with large, conspicuous raised areas Hackberry nipplegall maker (Pachypsylla celtidismamma)
Leaves with small raised areas Hackberry blistergall maker (Pachypsylla celtidivescula Riley) 
Affecting Stems, Twigs or Small Branches:
Signs or Symptoms Cause
Cellophane-like webbing in late summer Spider mites (Tetranychidae spp.)
Twigs deformed into dense witches’ broom Eriophyid mites / Powdery mildew complex
Affecting Larger Branches or Trunks:
Signs or Symptoms                                Cause
Borers / Bark beetles Flatheaded appletree borer(Chrysobothris femorata)
Clear to white oozing or frothy maladorous liquid exiting from wounds Bacterial wetwood / Slime flux

 

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Hawthorn

plant diagnostic_database

                               Hawthorn (Crataegus spp.)                          

Crataegus        

Affected Area:
  • Leaves                                                                   


                                                       

Plant Information:

 

Hawthorns are members of the rosaceae family, are known for their pretty spring flowers and showy fruit in summer and fall. Most hawthorns grow to 20-30' tall & wide, with thorns up to 2" long.  Hawthorns are tolerant of many soils but they should be well drained, pH adaptable.  Douglas hawthorn which grows more like a large shrub is native to Montana.

 

 

Affecting Leaves:
Signs or Symptoms           Cause 
Blackened and wilting leaves Fireblight (Erwinia amylovora)
Pale green or yellow leaves Iron chlorosis
Caterpillars associated with webbing Fall webworm (Hyphantria canea) or Western tent caterpillar (Malacosoma californicum)
Chewing leaves Pearslug (Caliroa cerasi) or Forest tent caterpillar (Malacosoma disstria)
Leaves curled in spring Apple aphid (Aphis pomi)
Reddish spotting on upper surface/orange pustules, spiny eruption on underside Cedar-Apple Rust (Gymnosporangium rusts)
Affecting Stems, Twigs or Small Branches:
Signs or Symptoms Cause
Blackened, wilting, and crooked tips Fireblight (Erwinia amylovora)
White, wax-covered insects Mealybug (Pseudococcidae) or Wooly hawthorn aphid (Eriosoma crateagi)
Affecting Larger Branches or Trunks:
Signs or Symptoms                                Cause
Clear to white oozing or frothy malodorous liquid exiting from wounds Bacterial wetwood and slime flux

 

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Honeylocust

plant diagnostic_database

                              Honeylocust (Gleditsia triacanthos)                          

Gleditsia        

Affected Area:
  • Leaves                                                                   


                                                       

Plant Information:

 

Honeylocust are fast growing deciduous trees in the Leguminosae family.  Honeylocust grow to heights of 35-70', with open spreading branches and leaves divided into many oval ¾-1½" long leaflets.  Honeylocust are late to leaf out; leaves turn yellow and drop early in fall.  Honeylocust are easily transplanted, withstanding a broad range of soil conditions, drought tolerant once established, and salt conditions, and hardy from zones 4-9.  Honeylocust make for a nice lawn tree, with light shade under tree allowing grass to grow well under it.

 

 

Affecting Leaves:
Signs or Symptoms           Cause 
Caterpillars chewing on leaves Fruittree leafroller (Archips argyrospila)
Leaflets distorted into thickened pods Honeylocust podgall midge (Dasineura gleditschiae)
Honeydew appearing on leaves Cottony maple scale (nymph stage on leaves) - (Pulvinaria innumerabilis)
Leaves turn bronze, may prematurely drop Honeylocust spider mite(Platytetranychus multidigituli) or Honeylocust rust mite (Aculops spp.)
Yellowed leaves Root damage cased by under or over watering
Affecting Stems, Twigs or Small Branches:
Signs or Symptoms Cause
Tips of twigs thickened, may have dieback Honeylocust podgall midge (severe injury killing growing points)
Scales Cottony maple scale (Pulvinaria innumerabilis)
Twigs with small splintering wounds Putnam's cicada [egg laying wounds] - (Platypedia putnami)
Affecting Larger Branches or Trunks:
Signs or Symptoms                                Cause
Areas of dead bark (cankers) or Discoloration and small pimple-like fruiting bodies (pycnidia) in the bark Cytospora canker (Valsa spp.,Leucostoma spp.) 
Amber colored gummy exudate (gummosis) Stress response from drought, sunscald, collar rot, cankers or other causes

 

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Honeysuckle

plant diagnostic_database

                              Honeysuckle (Lonicera spp.)                          

Lonicera        

Affected Area:
  • Leaves                                     

 


                                                       

Plant Information:

 

Honeysuckles are deciduous shrubs or vines with tubular, often fragrant flowers.  Easily grown in sun or light shade, adaptable to many soil types and pH levels, and prefers a well-drained soil.  Many types of birds use the flowers and fruit as sources of food.  They perform well with average summer watering and a severe pruning to keep in shape and looking refreshed.

 

 

Affecting Leaves:
Signs or Symptoms           Cause 
Leaves curled and with blackened margins Honeysuckle blight
Leaves tightly curled, associated bunchy growth Honeysuckle witches' broom aphid (Hyadaphis tartaricae)
Early season leaves curled, yellow Aphids
White powdery material on upper or lower surface of leaf Powdery mildew

 

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Iris

plant diagnostic_database

                             Iris (Iris spp.)                          

Iris        

Affected Area:
  • Leaves                                     

 


                                                       

Plant Information:

 

Iris is a diverse group of about 200 species, varying in flower color and form, cultural needs, and blooming season, although majority flower in spring or early summer.  Leaves swordlike or grasslike; flowers showy.  The four main groups are: bulbous, crested, beardless and bearded.  The last three have rhizomes as roots.  The most widely grown are tall bearded; in which many new varieties appear every year.

 

 

Affecting Leaves:
Signs or Symptoms           Cause 
Yellowing leaves Nitrogen deficiency or natural senescence.
Yellow leaves Aphids
Spots on leaves Iris Leaf Spot

 

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Juniper

 

 

plant diagnostic_database

                             Juniper (Juniperus spp.)                          

Juniperus virginiana        

Affected Area:

Plant Information:

 

Junipers are evergreen trees and shrubs with fleshy, berry-like cones.  Foliage is needlelike, scalelike, or both.  Foliage color varies from a dark green to light green, blue, sliver-blue, yellow and shades in between.  Junipers are the most widely used woody plants in the west; there's a form for almost every landscape.  Juniper types include ground cover forms a few inches to 2-3', taller prostrate shrubs, and taller spreading or erect tree types.  Junipers succeed in all soils except waterlogged.  They are best grown in full sun to light shade.

 

 

Affecting Needles:
Signs or Symptoms      Cause
Frothy masses on needles Juniper spittlebug (Clastoptera juniperinaBell).
Honeydew present Giant conifer aphids (Cinara spp.)
Needles chewed and fragments tied with webbing Juniper webworm (Dichomeris marginella)
Aphids on needles Giant conifer aphids (Cinara spp.)
Pale green or yellow needles Iron chlorosis
Needles tips bleached or brown Winter dessication or Vole injury
Needles become grayish, with small flecks Spruce spider mite (Oligonychus ununguis)
Scales on needles Juniper scale (Carulaspis juniperi Bouche) or Fletcher scale (Parthenolecanium fletcheri)
Affecting Twigs and Smaller Branches:
Signs or Symptoms Cause
Twig galls Juniper rusts (Gymnosporangium spp.)
Twig dieback Grasshoppers (Melanoplus spp.)Phytophthera Root or Crown Rot
Large aphids on branches, twigs Giant conifer aphids (Cinara spp.)
Brown felt-like material on needles and branches (higher elevations only) Brown felt blight (Herpotricha juniperi)
Affecting Trunk or Larger Branches:
Signs or Symptoms Cause
Witches' brooms or branch galls Juniper broom rust (Gymnosporangium speciosum)
Large aphids on branches, trunk Giant conifer aphids (Cinara spp.)
Affecting Roots and Ground Line Area:
Signs or Symptoms Cause
White root decay with white mycelial fans between bark and wood Armillaria root disease (Armillaria mellea)
Brown, discolored roots Phytophthera Root or Crown Rot


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Kale

 

 

plant diagnostic_database

                             Kale (Brassica oleracea var. acephala)                          

Kale        

Affected Area:

Plant Information:

 

Kale is a very hardy member of the cabbage family, with green or purple leaves, in which the central leaves do not form a head.  Kale can tolerate a lower temperature(<40°F) and pH(5.5-6.8) than can other brassicas.  In fact frost improves the taste.  Kale can be grown like cabbage, though its culture is easier because it is not as often besieged by pests who seem to prefer some of the other brassicas.

 

 

Affecting Leaves:
Signs or Symptoms      Cause
Yellow v-shaped spots on leaf margins Black rot (Xanthomonas campestris)
Yellowish leaves, lower leaves drop; stunted plants may have twisted stems, usually occurs soon after transplanting Fusarium yellows (Fusarium oxysporum)
Yellow leaves, older leaves first, slow growth Nitrogen deficiency
Yellow leaves Cold weather
Yellow, curled leaves; stunted plants Aphids 
Brown leaves that wilt and die Harlequin bug (Margantia histrionica)
Tan to dark-brown leaf margins Heat injury
Small holes, shothole injury Flea beetles (Phyllotreta spp.)
Large holes in leaves; outer leaves riddled Cabbage worms (Pieris rapaeor Cabbage looper
Affecting Roots:
Yellow, stunted plants that wilt during bright, hot days and recover at night Cabbage root maggots


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Kohlrabi

 

 

plant diagnostic_database

                            Kohlrabi (Brassica oleracea var. gongylodes)                          

Kohlrabi        

Affected Area:

Plant Information:


 

Kohlrabi looks like a kind of above ground turnip and is another member of the cabbage family.  Kohlrabi is eaten raw or cooked as a vegetable.  Plant seeds in spring, ½" deep, 6" apart.  Keep plants well watered as they are very shallow rooted.  Kohlrabi should be ready for harvest in 8 weeks when they are 2-2½ in size. 

Affecting Leaves:
Signs or Symptoms      Cause
Yellow v-shaped spots on leaf margins Black rot (Xanthomonas campestris)
Yellow leaves, older leaves first, slow growth Nitrogen deficiency
Tan to dark-brown leaf margins Heat injury
Small, pitted holes in leaves Flea beetles (Phyllotreta spp.)
Large holes in leaves Cabbage worms (Pieris rapae)
Affecting Roots:
Yellow, stunted plants that wilt during bright, hot days and recover at night Check roots for the following: slimy, winding tunnels mean Cabbage root maggots


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Lettuce

 

 

plant diagnostic_database

                           Lettuce (Lactuva sativa)                          

Lettuce        

Affected Area:

Plant Information:

 

The 3 most common types of lettuce are:  leaf or bunching, head (including butterhead and crisphead), and cos or romaine.  Lettuce will happily grow just about anywhere with ample sunlight, cool nights (50-60°F), loose soil, and plenty of moisture.  Optimum lettuce growing temperatures are 60-65° F.  To high of temperatures will cause seed stalk formation or bolting, however there are many bolt-resistant cultivars.  Lettuce is a heavy nitrogen feeder with a limited root system.  Plant every 30 days for a consistent supply.

 

 

Affecting Leaves and Heads:
Signs or Symptoms      Cause
Bleached center leaves are dwarfed, curled or twisted Aster yellows (Phytoplasma)
Yellow or pale leaves, stunted plants Leaf hoppers
Yellow, distorted new growth Tarnished plant bug (Lygus pratensis)
Yellow leaves, slow growth, bitter taste Nitrogen deficiency
Yellow, curled leaves Aphids
Light green or yellow crinkled leaves with enlarged veins Big vein: caused by a virus-like organism
Dull gray-green to brown leaves Thrips
Mottled, ruffled leaves; stunted plants Mosaic viruses
Leaf margins turn brown and die Tipburn, prevalent in hot weather
Browning and dwarfing of plant; Velvety, white growth on leaves Downy Mildew
Powdery dust on upper leaf surfaces Powdery mildew
Outer leaf margins tan, blistering of leaves Freezing injury
Wilting, sudden collapse of outer leaves on mature plants Sclerotinia drop
Lower leaves and midribs rot near the base of the plant first Bottom rot or Rhizoctonia (Rhizoctoniaspp.)
Slimy, rotted heads Gray Mold (Botrytis cinerea)
Midrib discolored High temperatures (> 80° F.)
Lettuce malformed Boron or phosphorus deficiency
Brown center and rosetting Calcium deficiency
Small holes in leaves, shot-hole injury Flea beetles (Phyllotreta spp.)
Large hole in leaves; excrement found at base of head Cabbage looperImported cabbage worm(Pieris rapae) , Beet armyworm, and Corn earworms (Heliothis zea)
Large holes in leaves with slimy trails Slugs and snails
White or translucent, irregular tunnels in leaves Leafminers
Affecting Whole Plant:
Seed doesn't germinate High soil and/or air temperatures
Seedlings clipped off at soil line Cutworms (Noctuidae spp.)


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Lilac

 

 

plant diagnostic_database

                          Lilac (Syringa spp.)                          

Syringa        

Affected Area:

Plant Information:


Lilacs are deciduous shrubs or small trees in the Oleaceae family.  Grown widely for their fragrant flowers, over 500 cultivars of the common lilac have been developed.  Neutral soils are the best to grow lilacs in, average watering but can withstand some drought once established.  Flowers best in full sun, but will tolerate light shade.  Lilacs are used as hedges, screens and back of border plantings.  Prune after flowering so not to minimize the next year's flower display.

 

Affecting Leaves:
Signs or Symptoms      Cause
Edge of leaves cut in semicircle Leafcutter bees (Megachile spp.)
Edge of leaves notched Black vine weevil (Otiorhynchus sulcatus)
Leaves with blotchy mines Lilac leafminer (Caloptilia syringella)
Leaves blacken and wilted Bacterial brown spot (Pseudomonas syringaepv. syringae)
White powdery material on upper or lower surface of leaf Powdery mildew (Microsphaera penicillata)
Leaves turn a rusty color Rust Mites (eriophyid)
Affecting Twigs and Smaller Branches:
Scales Oystershell scale (Lepidosaphes ulmi)
Borers Lilac/ash borer (Podosesia syringae)


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Linden

plant diagnostic_database

                                 Basswood, Linden (Tilia spp.)                          

Tilia        

Affected Area:
  • Leaves                                                                   


                                                       

Plant Information:


The genus Tilia consists of about 40 species of large or medium-sized deciduous trees.  Trees of this genus thrive in loamy, moist, fertile soil, but will tolerate poor soils and adverse conditions.  Trees of this genus vary greatly in size, shape, leaf, and growth rate.  Lindens are primarily used as ornamental shade and street trees.  The wood of Linden is generally not suitable for lumber as it is soft and rots readily.  The name "basswood" or "bastwood" is dervided from the word bast (inner bark) that consists of long, tough fibers once used in the production of mats and clothing.

 

 

Affecting Leaves:
Signs or Symptoms           Cause 
Leaves being chewed                                                             Fruittree leafroller (Archips argyrospila) or Speckled green fruitworm (Orthosia hibisci)
Small pouch galls form on leaf surface Linden fingergall mite (Eriophyid mite)
Velvety patches on underside of leaves (littleleaf linden) Linden fingergall mite (Eriophyid mite)
Pale green or yellow leaves Iron chlorosis
Leaves strongly cupped Herbicide injury. See Abiotic Injury.
Aphids Linden aphid (Myzocallis tiliae)
Wilting and dieback of portions of tree, originating from roots Verticillium wilt (Verticillium spp.)
Affecting Stems, Twigs or Small Branches:
Signs or Symptoms Cause
Large cottony insect develops in late spring Cottony maple scale (Pulvinaria innumerabilis)
Affecting Larger Branches or Trunks:
Signs or Symptoms                                Cause
Areas of dead bark with discoloration and small pimple-like fruiting bodies (pycnidia) Cytospora canker (Valsa spp.,Leucostoma spp.)
Wilting and dieback of portions of tree, originating from roots Verticillium wilt (Verticillium spp.)

 

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Maple

plant diagnostic_database

                                Maple (Acer spp.)                          

Acer glabrum        

Affected Area:
  • Leaves                                                                   


                                                       

Plant Information:

 

Maples are deciduous trees or large shrubs in the Aceraceae family, and propagate by seeds, which have wings. The seeds fall, spinning toward the ground like a helicopter.  Maple trees will vary in size by species, some reaching only fifteen to twenty feet, while other can grow to seventy feet or more in height. Maple trees have inconspicuous clusters of green flowers at the end of the young shoots.  All maple trees have three principal veins radiating from the base of the leaf. The leaves vary in size by species; some reaching only an inch or so across, while others can be as large as six or more inches.  Maple trees have many uses. The wood of maple trees is excellent as a source of fuel, and can be made into high quality charcoal. The wood is most often used for its ornamental quality. Furniture is often made from the sturdy, fine-grained wood. Maple trees have a sap that can be made into sugar easily.  Their great canopy of leaves calls for a steady, constant supply of water. 

  • USDA Plants Database
  • Lady Bird Johnson Wildflower Center
Affecting Leaves:
Signs or Symptoms           Cause 
Leaves chewed Fruittree leafroller (Archips argyrospila)
White flecks on leaves Leafhopper (Erythroneura spp.)
Black to brown spots on leaves Anthracnose (Kabatiella sp.) or Septoria leaf spot and canker (Septoria sp.) or Tar spot (Rhytisma sp.)
Patches of reddish hairs (Rocky Mountain maple) Eriophyid mites
Sucking insects on leaves, often honeydew Boxelder and maple aphids (Periphyllusspp.) or Cottony maple scale (nymphs) (Pulvinaria innumerabilis)
Leaves yellowed (particularly silver maple) Iron chlorosis
Affecting Stems, Twigs or Small Branches:
Signs or Symptoms Cause
Twigs with row of irregularly shredded punctures Cicada injury (Platypedia putnami)
Large cottony insect on twigs Cottony maple scale (Pulvinaria innumerabilis)
Affecting Larger Branches or Trunks:
Signs or Symptoms                                Cause
Clear to white oozing or frothy malodorous liquid exiting from wounds Bacterial wetwood and slime flux
Areas of dead bark with discoloration and small pimple-like fruiting bodies (pycnidia) in the bark Cytospora canker (Valsa spp.,Leucostoma spp.)
Large dead and discolored areas on southwest side of trunk Winter sunscald
Borers Flatheaded appletree borer(Chrysobothris femorata)
Wilting and dieback of portions of tree, originating from roots Verticillium wilt (Verticillium spp.)

 

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Mountain Ash

plant diagnostic_database

                               Mountain Ash (Sorbus spp.)                          

Sorbus        

Affected Area:
  • Leaves                                                                   

 

                                                       

Plant Information:

 

Mountain ash, a member of the Rosaceae family, known for its fern-like foliage, clusters of white flowers and bright orange-red fruit.  Most species are trees ranging from 20-60' tall.  Mountain ash grow in average well-drained soils, pH adaptable, and hardy from zones 3 to 7.  Most species make good lawn trees since the birds love the fruit.  There are several tall shrub species(13') native to Montana, scopulina and sitchensis, which are found near moist areas and forest openings.

 

 

  • USDA Plants Database
  • Lady Bird Johnson Wildflower Center
Affecting Leaves:
Signs or Symptoms           Cause 
Yellow, raised pouches Eriophyid mites
Orange spots Juniper rusts (Gymnosporangium spp.)
Rusty scabs on leaf Blister mite. See Eriophyid mites.(Phytoptus spp.)
Chewing leaves Pearslug (Caliroa cerasi)
Aphids Apple aphid (Aphis pomi)
Blackened and wilting leaves Fireblight (Erwinia amylovora)
Affecting Stems, Twigs or Small Branches:
Signs or Symptoms Cause
Aphids Wooly aphids (Eriosoma sp.)
Scales Oystershell scale (Lepidosaphes ulmi) or Mealybug (Phenacoccus spp.)
Affecting Larger Branches or Trunk:
Signs or Symptoms                                Cause
Blackened, wilting, and crooked tips Fireblight (Erwinia amylovora)
Discolored areas and dead bark containing small pimple-like fruiting bodies (pycnidia) Cytospora canker (Valsa spp.,Luecostoma spp.)
Large dead and discolored areas on southwest side of trunk Winter sunscald
Clear to white oozing or frothy malodorous liquid exiting from wounds Bacterial wetwood and slime flux
Borers Flaheaded appletree borer (Chrysobothris femorata)

 

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Oak

plant diagnostic_database

                              Oak (Quercus spp.)                          

Quercus        

Affected Area:

Plant Information:

 

Oaks are decidious trees in the Fagaceae family known for their fruit (acorns) and wood.  The wood is tough, durable, and attractively grained; it is especially valued in shipbuilding and construction and for flooring, furniture, tool handles, barrels and veneer.  There are more than 80 species in North America, which are popular urban trees that tolerate a wde range of soil conditions.  In Montana, bur oak is one of easiest to grow and tolerates more adverse conditions.  Oaks have spirally arranged leaves with lobed margins in many species; some have serrated leaves or entire leaves with smooth margins. Many species do not drop dead leaves until spring.  The bark of some oaks has been used in medicine, in tanning, and for dyes.

 

 

 

  • USDA Plants Database
  • Lady Bird Johnson Wildflower Center
Affecting Leaves:
Signs or Symptoms           Cause 
Leaves tied together with silk, chewed Oak leafroller (Archips semiferana)
Black/brown spotting on leaves Anthracnose (Apiognomonia quercina)
Frothy mass on leaf vein Spittlebugs (Clastoptera spp.)
Insects sucking on leaves Spider mites (Oligonychus platani)
Small balls on leaves Gall wasps (Cynipidae spp.)
Cottony growth on leaves, near midrib Gall wasps (Cynipidae spp.)
Pale green or yellow leaves Iron chlorosis
Affecting Stems, Twigs or Small Branches:
Signs or Symptoms Cause
Twigs shredded by multiple punctures Cicada oviposition injury (Platypedia putnami) 
Witches' brooms on Gambel oak Oak witches' broom (Articularia quercina)
Areas of dead bark with discoloration and small pimple-like fruiting bodies (pycnidia) in the bark Cytospora canker (Valsa spp.,Leucostoma spp.)
Affecting Larger Branches or Trunk:
Signs or Symptoms                                Cause
Clear to white oozing or frothy malodorous liquid exiting from wounds Bacterial wetwood / slime flux
Stem decay and/or hoof-shaped fruiting bodies (conks) on Gambel oak White trunk rot of oak (Phellinus everhartii)
Affecting Fruit:
Signs or Symptoms                                Cause
Grubs feeding in acorn Acorn weevils (Carculio spp.)

 

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Onion

plant diagnostic_database

                             Onion (Allium cepa)                          

Onion        

Affected Area:

                                                

Plant Information:

 

Onions have many shapes, colors, and tastes of onions as there are uses for them in the kitchen:  tender spring onions, red, yellow and white storage standbys, bunching onions, and gourmet shallots.  Onions are a hardy, cool season plant that grows over a wide range of temperatures.  Northern areas need cultivars that form bulbs under longer day conditions.  Best growth occurs at temperatures of 55-75° F, in fertile, well drained soils high in organic matter.  Onions are shallow rooted and need regular irrigation.  You can plant seeds, sets or field grown transplants.

 

 

  • USDA Plants Database
  • Lady Bird Johnson Wildflower Center
Affecting Leaves:
Signs or Symptoms           Cause 
Yellow leaves, slow growth Nitrogen deficiency
Yellow leaves, dwarfed plants Aphids
Brown leaf tips; white blotches on leaves Onion thrips
Tips of leaves die, pale green to brown leaf spots; later leaves are black with a purple, furry mold Downy mildew (Peronospora effusa)
Leaf tips turn brown and die Hot, dry weather and/or excessive heat
Pale, green-silvery leaf spots Can be a reaction to excessive rain or hail
Papery, white leaf spots with a characteristic lengthwise split; brown leaf tips Botrytis leaf blight
Affecting Stems, Twigs or Small Branches:
Signs or Symptoms Cause
Seedlings develop weak, water-soaked stems and fall over Damping-off
Wilted, yellow plants Wireworm
Yellow, wilting plants Fusarium yellows (Fusarium oxysporum)
Yellow, dying plants Onion or seedcorn maggot
Affecting Bulbs:
Signs or Symptoms                                Cause
Gray, water-soaked appearance of outer bulb scales Caused by high (> 85° F.) temperatures
Bleached, soft bulbs Sunscald
Water-soaked, soft bulbs Freezing injury
Roots turn pinkish, shrivel and die Pink root
Sunken, dry, brown-black areas around neck, rotted neck; gray mold on bulb surface Neck rot
Dark-green or black spots with concentric rings on bulb and neck Onion smudge
Rotted bulb Purple blotch or white rot
Poor bulb formation, small size Potassium or nitrogen deficiency, late planting, or Onion thrips

 

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Parsnip

plant diagnostic_database

                            Parsnip (Pastinaca sativa)                          

Parsnip        

Affected Area:
  • Leaves                            
  • Roots                                      

Plant Information:

 

Parsnips are grown for their delicate-tasting roots, which can grow up to 15" long and 3-4" across at the top.  They growing culture is much like a carrot except parsnips require less fertilizer and a higher pH (6.0-6.8).  Optimum growing temperatures are 60-64°F, but will tolerate temperatures as low as 35-40°F.  Parsnips are mature about 4 months after planting, ready for harvest in the fall, or if left in the ground thru winter if heavily mulched the flavor will be enhanced.

 

 

  • USDA Plants Database
  • Lady Bird Johnson Wildflower Center
Affecting Leaves:
Signs or Symptoms           Cause 
Yellow, dwarfed young leaves, bushy growth Carrot yellows
Yellow leaves, older first; stunted plants. Nitrogen deficiency
Yellow, curled leaves Aphids
Dark spots with yellow borders Cercospora leaf blight (Cercospora spp.) if younger leaves are affected. Alternaria leaf blight (Alternaria spp.)if older leaves are affected.
Affecting Roots:
Signs or Symptoms Cause
Yellow, stunted plants that wilt during bright, hot days and recover at night Root injury. Check for Wireworms or Root-knot nematodes (Meloidogyne spp.)
Dark tunnels, often in a zig-zag pattern, on upper and outer part of root Carrot weevil (Otiorynchus spp.)
Dark cankers on roots, root deterioration Brown canker
Rotted roots Crop rotation needed or soil worked when wet

 

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Pea

plant diagnostic_database

                             Pea (Pisum santivum)                          

Pea        

Affected Area:

                                              

Plant Information:

 

Peas are a cool-season moisture-loving crop, grown to utilize the whole edible pod or just the green peas.  Optimum growing temperatures are 60-75° F.  All peas grow on vines, most types needing support to grow on.  Low-nitrogen fertilizer is used with peas because they, like other legumes, draw nitrogen from the atmosphere with the help of soil bacteria.  Peas prefer a pH of 5.5-6.8 and lighter soils with good organic matter.

 

 

  • USDA Plants Database
  • Lady Bird Johnson Wildflower Center
Affecting Leaves:
Signs or Symptoms           Cause 
Yellow, curling leaf margins, wilted plants; flowers and pods drop Potato leaf hoppers
Yellow, distorted new growth Tarnished plant bug (Lygus pratensis)
Yellow leaves, slow growth Nitrogen deficiency
Yellow, withered, thickened and curled leaves; flowers may drop Pea aphids
Yellow crinkled, mottled, curled leaves Mosaic virus
Mottled, yellow, crumpled leaves; rosetting Pea enation virus
Yellow leaves, stems yellow inside; dwarfing and wilting Fusarium wilt (Fusarium oxysporum)
Velvety, white growth on leaves Downy Mildew (Peronospora effusa)
Powdery, white leaf spots Powdery mildew
White stippled leaves which later become bronzed Mites
White or translucent, irregular tunnels in leaves Leafminers
Leaf holes on young plants Striped and spotted Cucumber beetles(Acalymma vittata)
Large holes in leaves Army Cutworms (Euxoa auxiliaris)
Affecting Seed, Seedling, Root:
Signs or Symptoms Cause
Seedlings clipped off at soil line Cutworms (Noctuidae spp.)
Stems rot near soil line and plant collapses; seeds do not germinate Damping off
Poor germination, damaged seedling stem; deformed, spindly seedlings Seed corn maggots
Affecting Fruit:
Signs or Symptoms                                Cause
Blossoms drop Excessive heat or rain
Blossoms drop or pods fail to develop Copper and/or molybdenum deficiency
Brown spot or cavity on seeds Manganese deficiency
White, powdery spots on pods Powdery mildew
Holes in blossoms, tunnels in seeds Pea weevil adults


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Peach

plant diagnostic_database

Stone Fruits:  Apricot, Cherry Chokecherry, Peach, Plum, etc.

(Prunus spp.) 

Prunus

Affected Area:

Plant Information:


The genus Prunus is comprised of nearly 200 species of five subgenera:  plums and apricots, almonds and peaches, umbellate cherries, deciduous racemose cherries, and the evergreen racemose cherries.  The species of this genus range from shrubs to trees over 90 ft. tall.  Over 100 species have been cultivated as either ornamentals or as food crops.  Trees for fruit production and many ornamentals are generally propagate by budding or grafting, while seed propagation is reserved for generation of rootstocks and breeding programs.  The most common rootstock:scion combinations are:  almond:almond and plum; apricot:apricot; mazzard cherry:sweet cherry; mahaleb cherry:sweet and sour cherry; peach:peach, almond, apricot, plum; American plum:plum in cold regions; Bessey cherry:dwarf peaches. 

 

Affecting Whole Plant:
Signs or Symptoms Cause 
Tree decline in vigor Phytophthora root rot (Phytophthoraspp.), Cytospora Canker (Valsa spp.,Leucostoma spp.), or Verticillium wilt(Verticillium spp.)
Affecting Leaves:
Signs or Symptoms Cause
Leaves chewed, no associated webbing Pearslug (Caliroa derasi)
Upper surface of the leaf skeletonized Pearslug (Caliroa cerais) or Apple Thorn Skeletonizer
Webbing associated with chewing Fall webworm (Hyphantria cunea Drury),Ugly Nest caterpillar (Archips cerasivorana), or Western tent caterpillar(Malacosoma californicum)
Leaves with small, circular holes Shot hole disease 
White flecking injuries  White apple leafhopper (Typhlocyba pomaria McAtee) or Lacebug (Corythuca padi), on chokecherry (Corythuca spp.)
White powdery material on upper or lower surface of leaf Powdery mildew
Leaves yellow Iron chlorosis or X-disease
Leaves with small, pouch or finger-like projections Fingergall mites (Phytoptus species)
New leaves curled Aphids: Green peach aphid (Myzus persicae), Leafcurl plum aphid (Anuraphis helichrysi), or Black cherry aphid (Myzus cerasi)
New leaves curled and thickened and red/purple Peach leaf-curl disease
Affecting Larger Branches or Trunks:
Signs or Symptoms Cause
Black galls on branches Black knot of cherry (Apiosporina morbosa) 
Stem decay and/or hoof-shaped fruiting body (conk) Decay fungus (Phellinus pomaceus)
Scales Scale: European fruit lecanium (Parthenolecanium corni) or Oystershell scale (Lepidosaphes ulmi)
Small pinhead-sized exit holes in branches Shothole borer (Scolytus rugulosus)
Branches die back Cytospora canker (Valsa spp.,Leucostoma spp.) or Shothole borer (Scolytus rugulosus)
Gumming and dark colored branches Shothole borer (Scolytus rugulosus), or Cytospora canker (Valsa spp.,Leucostoma spp.) or  Bacterial Blight (Pseudomonas syringae)
Dead bark with discoloration and small pimple-like fruiting bodies (pycnidia) Cytospora canker (Valsa spp.,Leucostoma spp.)
Wilting and dieback of portions of tree, originating from roots Verticillium wilt (Verticillium spp.)
Affecting Ground Line Area of Trunk:
Signs or Symptoms Cause
Discolored tissue under bark at ground line Phytophthora root rot (Phytopthora sp.)
Gall at ground line Crown gall (Agrobacterium tumefaciens)
Affecting Fruit:
Signs or Symptoms Cause
Fruit tunneled European earwig (Forficula auricularia L.)
Fruit with sunken, corky areas Plant bug (Lygus species), Hail injury, or Boxelder bug (Boisea trivittata)
Puncture wounds in fruit Bird damage (Robins, finches, etc.)
Chokecherry fruit enlarged, hollow Chokecherry gall midge (Contarinia virginianae)
Maggots in cherry fruit Western cherry fruit fly (Rhagoletis indifferens Curran

 

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Pear

plant diagnostic_database

                             Pear (Pyrus spp.)                          

Pyrus        

Affected Area:

Plant Information:

Deciduous fruit trees in the Rosaceae family, with leathery, glossy bright green leaves and clusters of white flowers in the spring.  Pears are of the oldest cultivated fruits in the world dating back over 5,000 years to Chinese farmers.  Pear trees are of medium size typically reaching 15-30 feet tall and 10-20 feet wide. Most varieties require a partner for cross-pollination however some do not.  There are over 3000 varieties, but only approximately 10 varieties in commercial production.  The Bartlett variety comprises over 75% of the United States pear crop. Other European pear varieties include d'Anjou, Bosc, Comice, Seckel, and Winter Nelis. The European pear is noted for its soft, juicy flesh. The skin color is medium green to yellow, depending on fruit maturity and the variety. Skin texture can be smooth or rough. Fruit shape ranges from the classic pear shape (round base with narrow neck) to a rounded oblong shape with no clearly defined neck area. 

 

  • USDA Plants Database
  • Lady Bird Johnson Wildflower Center
Affecting Leaves:
Signs or Symptoms           Cause 
Large holes chewed in leaves Redhumped caterpillar (Schizura concinna) , or Forest tent caterpillar(Malacosma disstria 
Silken tents produced Western tent caterpillar or Fall webworm(Hyphantria cunea)
Caterpillar living within a case Snailcase bagworm (Apterona helix )
Terminal leaves curled and tied together with silk Fruittree leafroller or Obliquebanded leafroller
Skeletonized leaves Apple and thorn skeletonizer (Choreutis pariana) or Apple flea beetle (Phyllotretaspp.)
"Shothole" feeding wounds in leaf, usually with sucker growth Apple flea beetle (Phyllotreta spp.)
Raised leafmines Western tentiform leafminer
White powdery material on upper or lower surface of leaf Powdery mildew
Pale green or yellow leaves Iron chlorosis 
Rust orange spots Juniper rusts
Black mold on surface of leaf Apple scab (Venturia inaequalis) 
Rusty blisters or scabby patches on leaves Blister mites. See Eriophyid mites.
Bronzing of leaves Two-spotted spidermite or McDaniel spider mite
Curling distortions of new growth in spring Rosy apple aphid
Blackened and wilted leaves Fireblight (Erwinia amylovora)
Affecting Stems, Twigs or Small Branches:
Signs or Symptoms Cause
Twigs shredded by a line of multiple punctures Cicada oviposition wounds
Blackened, wilting, and crooked tips Fireblight (Erwinia amylovora)
Black beetle tunneling, with small exit holes Shothole borer
Scales on twigs Oystershell scale or European fruit lecanium
Cottony insects on twigs Woolly apple aphid or Mealybugs
Discolored areas, dead bark containing small pimple-like fruiting bodies (pycnidia) Cytospora canker (Valsa spp.,Leucostoma spp.)
Affecting Larger Branches or Trunk:
Signs or Symptoms                                Cause
Boring into trunk Flatheaded appletree borer(Chrysobothris mali)
Bark beetle tunneling, small exit holes Shothole borer
Cottony insects on trunk and/or roots Woolly apple aphid
Internal decay and/or shelf-like fruiting structures (conks) Decay fungus 
Wilting and dieback of portions of tree, originating from roots Verticillium wilt (Verticillium spp.) 
Affecting Ground Line Area of Trunk:
Signs or Symptoms                                Cause
Discolored tissue under bark at ground line Phytophthora root rot (Phytophthoraspp.)
Galls at ground line Crown gall
Affecting Roots:
Signs or Symptoms                                Cause
White root decay and white mycelial fans between bark and wood Armillaria root disease (Armillaria spp.) 
Affecting Fruit:
Signs or Symptoms                                Cause
Tunneling in fruit Codling moth (Cydia pomonella)
Scaring or sabbing of fruit Fruittree leafroller, hail injury, or Apple scab (Venturia inaequalis)



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Pepper

plant diagnostic_database

                            Pepper (Capsicum annuum)                          

Pepper        

Affected Area:

                                              

Plant Information:

 

Sweet pepper, also called bell pepper and hot peppers are warm-weather shrubs from the tropics.  The plants usually grow about 2" tall and wide.  The fruit of sweet peppers grow 3-4" long and 2-3" wide; they can be harvested green (immature) or if allowed to ripen they turn yellow, orange or red.  Hot peppers vary greatly in size and shape, all have a pungent flavor.  Peppers are started indoors 6-8 weeks before the minimum night temperatures are above 55°F.  Peppers need full sun and warm growing conditions to be productive.

 

 

  • USDA Plants Database
  • Lady Bird Johnson Wildflower Center
Affecting Leaves:
Signs or Symptoms           Cause 
Small, yellow-green spots, turning brown with lighter centers; near leaf margins first Bacterial spot (Xanthomonas campestris)
Mottled, yellow, curled, thick and leathery leaves Mosaic virus
Yellow leaves wilt and curl; shiny and sticky leaves Aphids
Small holes chewed in leaves Flea beetles (Phyllotreta spp.)
Circular, dark spots on leaves Alternaria Leaf Blight
New growth small, discolored, or deformed Curly Top
Affecting Whole Plant:
Signs or Symptoms Cause
Young plants topple over; weak stem at soil line Damping off
Yellow leaves, gradual wilting Verticillium wilt (Verticillium spp.)
Yellowing and drooping of shoots and leaves at base of plant first. Cross section of infected stem has reddish-brown vascular system. Occurs when temperature is 80-90° F. Fusarium wilt (Fusarium oxysporum)
Affecting Fruit:
Signs or Symptoms                                Cause
Plants have blossoms, but no peppers Extreme heat or cold
Fruit blossoms drop prematurely; fruit is misshapen and discolored Low temperature during blossoming and/or uneven growing conditions
White or tan-colored, sunken, spots near tips of fruit; most often on earliest fruit during dry periods; up to 1/3 of the fruit may become dark and shriveled Blossom end rot
Sunken, white papery-looking areas on side of fruit exposed to the sun Sunscald
Small, dark brown, wartlike spots on fruit; most prevalent during damp weather Bacterial spot (Xanthomonas campestris)
Large, yellow to dark brown spots on ripe peppers, followed by rotting; spots have black-specked centers Anthracnose
Feeding at seed core with hole near stem end of pepper; sawdusty excrement is usually visible at stem end; peppers often rot and color early European corn borer (Ostrinia nubilalis)

 

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Pine

 

 

plant diagnostic_database

                             Pine (Pinus spp.)                          

Pinus ponderosa        

Affected Area:

Plant Information:

Pines are evergreen trees and shrubs with over 90 species in the northern hemisphere.  Their number of needles in a bundle and size and shape of cones are the characteristics by which pines are classified.    The pines are of primary importance in the production of timber, pulp and paper production.   Turpentine, pine-wood oils, wood tars, and rosin are obtained from the wood of several species.  The leaf oils of several species are used in the manufacture of medicines and the seeds of several others are suitable for food (pine nuts).  Generally pines are more tolerant of adverse soil and climatic conditions than spruce and firs.  Most pines are pyramidal in shape, but some can be pruned into hedges and screens

 

Affecting Needles:
Signs or Symptoms      Cause
Mottled yellowing of needles on a branch Winter exposure injury
Needles to exterior of tree bleached or brown, developing late winter Winter dessication
Discoloration, needle drop of current or previous year's growth Needle casts (Bifusella sp.,Davisomycella sp., Elytoderma deormans, Lophodermella sp.,Lophoedermium sp.); or Giant conifer aphids (Cinara spp.)
Brown felt-like material on needles (high elevations) Brown felt blight (Neopeckia coulteri)
Needles twisted, stunted Eriophyid mites (Trisecatus spp.)
Aphids on needles Giant conifer aphids (Cinnara spp.)
Scales on needles Pine needle scale (Chionaspis pinifoliae)
Whole tree fades, reddens Mountain pine beetle (Dendroctonus ponderosae Hopkins)
Affecting Twigs and Smaller Branches:
Signs or Symptoms Cause
Galls on small branches that turn bright orange/yellow in spring Western gall rust (Endocronartium harknessii)
Swollen and/or twisted terminal growth Herbicide injury. See Chemical Injury.
Affecting Larger Branches or Trunk:
Signs or Symptoms Cause
Tunnels oozing popcorn-like white pitch, often near crotches Pine moth (Dioryctria spp.)
Galls on large branches or trunk Western gall rust (Endocronartium harknessii)
Cankers, with resin and squirrel chewing Comandra rust [in lodgepole pine] - (Cronartium comandrae)
Roughened bark and resin production White pine blister rust (on five needle pines)
Fungal fruiting bodies (mushrooms, conks) present Stem decay fungi (various species)
Open wounds, internal decay, swollen areas in stem Stem decay fungi (various species)
Regular row of holes Woodpeckers
Bark beetles Engraver beetles (Ips spp.), Mountain pine beetles (Dendroctonus ponderosae), or Red turpentine beetle (Dendroctonus valens LeConte)
Small shoots emerging from the branch
Affecting Roots and Ground Line Area:
Signs or Symptoms Cause
White root decay with white mycelial fans between bark and wood Armillaria root disease (Armillaria mellea)
Affecting Cones:
Signs or Symptoms Cause
Cones tunneled by caterpillars Coneworms (Dioryctria spp.)
Sucking on developing cones. Conifer Seed Bugs


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Plum

plant diagnostic_database

Stone Fruits:  Apricot, Cherry Chokecherry, Peach, Plum, etc.

(Prunus spp.) 

Prunus

Affected Area:

Plant Information:


The genus Prunus is comprised of nearly 200 species of five subgenera:  plums and apricots, almonds and peaches, umbellate cherries, deciduous racemose cherries, and the evergreen racemose cherries.  The species of this genus range from shrubs to trees over 90 ft. tall.  Over 100 species have been cultivated as either ornamentals or as food crops.  Trees for fruit production and many ornamentals are generally propagate by budding or grafting, while seed propagation is reserved for generation of rootstocks and breeding programs.  The most common rootstock:scion combinations are:  almond:almond and plum; apricot:apricot; mazzard cherry:sweet cherry; mahaleb cherry:sweet and sour cherry; peach:peach, almond, apricot, plum; American plum:plum in cold regions; Bessey cherry:dwarf peaches. 

 

Affecting Whole Plant:
Signs or Symptoms Cause 
Tree decline in vigor Phytophthora root rot (Phytophthoraspp.), Cytospora Canker (Valsa spp.,Leucostoma spp.), or Verticillium wilt(Verticillium spp.)
Affecting Leaves:
Signs or Symptoms Cause 
Leaves chewed, no associated webbing Pearslug (Caliroa derasi)
Upper surface of the leaf skeletonized Pearslug (Caliroa cerais) or Apple Thorn Skeletonizer
Webbing associated with chewing Fall webworm (Hyphantria cunea Drury),Ugly Nest caterpillar (Archips cerasivorana), or Western tent caterpillar(Malacosoma californicum)
Leaves with small, circular holes Shot hole disease 
White flecking injuries  White apple leafhopper (Typhlocyba pomaria McAtee) or Lacebug (Corythuca padi), on chokecherry (Corythuca spp.)
White powdery material on upper or lower surface of leaf Powdery mildew
Leaves yellow Iron chlorosis or X-disease
Leaves with small, pouch or finger-like projections Fingergall mites (Phytoptus species)
New leaves curled Aphids: Green peach aphid (Myzus persicae), Leafcurl plum aphid (Anuraphis helichrysi), or Black cherry aphid (Myzus cerasi)
New leaves curled and thickened and red/purple Peach leaf-curl disease
Affecting Larger Branches or Trunks:
Signs or Symptoms Cause 
Black galls on branches Black knot of cherry (Apiosporina morbosa) 
Stem decay and/or hoof-shaped fruiting body (conk) Decay fungus (Phellinus pomaceus)
Scales Scale: European fruit lecanium (Parthenolecanium corni) or Oystershell scale (Lepidosaphes ulmi)
Small pinhead-sized exit holes in branches Shothole borer (Scolytus rugulosus)
Branches die back Cytospora canker (Valsa spp.,Leucostoma spp.) or Shothole borer (Scolytus rugulosus)
Gumming and dark colored branches Shothole borer (Scolytus rugulosus), orCytospora canker (Valsa spp.,Leucostoma spp.) or Bacterial Blight (Pseudomonas syringae)
Dead bark with discoloration and small pimple-like fruiting bodies (pycnidia) Cytospora canker (Valsa spp.,Leucostoma spp.)
Wilting and dieback of portions of tree, originating from roots Verticillium wilt (Verticillium spp.)
Affecting Ground Line Area of Trunk:
Signs or Symptoms Cause 
Discolored tissue under bark at ground line Phytophthora root rot (Phytopthora sp.)
Gall at ground line Crown gall (Agrobacterium tumefaciens)
Affecting Fruit:
Signs or Symptoms Cause 
Fruit tunneled European earwig (Forficula auricularia L.)
Fruit with sunken, corky areas Plant bug (Lygus species), Hail injury, or Boxelder bug (Boisea trivittata)
Puncture wounds in fruit Bird damage (Robins, finches, etc.)
Chokecherry fruit enlarged, hollow Chokecherry gall midge (Contarinia virginianae)
Maggots in cherry fruit Western cherry fruit fly (Rhagoletis indifferens Curran

 

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Poplar

plant diagnostic_database

                                 Cottonwood, Poplar (Populus spp. excluding P. tremuloides)                          

Populus spp.        

Affected Area:

Plant Information:

Populus 

Cottonwood trees are all known for rapid growth. They grow best with regular deep watering, ensuring roots grow deeply to become drought tolerant.  Do not plant near water lines or sewers as their roots are invasive.  There are 30-35 species of poplars and numerous hybrids and named cultivars.  Cottonwoods are commonly used in windbreak and fence row plantings. 

  

 

Affecting Leaves:
Signs or Symptoms           Cause 
Leaves chewed Cottonwood leaf beetle (Chrysomela scripta), Spiny elm caterpillar (Nymphalis antiopa), Fall webworm (Hyphantria cunea), or Tussock moth (Dasychira vagans)
Webbing/Tents produced Fall webworm (Hyphantria canea),Western tent caterpillar (Malacosoma californicum), or Forest tent caterpillar(Malacosoma disstria)
Small holes chewed in leaves Flea beetles (Chrysomelidae)
Leaves tunneled Aspen leafminer (Phyllocnistis populiella)
Leaves spotted with young leaves blackened Shoot blight (Venturia populina) or Frost injury
Black spots with yellow margins Marssonina blight (Marssonina populi)
Black, irregular spots Septoria leaf spot and canker (Septoria popolicole)
Blackish-brown round spot, which drops out of leaf, leaving shothole-like appearance Ink spot (Ciborinia whetzelii)
Rust to orange colored spots Conifer-aspen rust (Melampsora spp.)
Yellowed leaves Root damage caused by under or over watering, or Iron chlorosis
White powdery material on upper or lower surface of leaves Powdery mildew (Erysiphe cichoracerum)
Leaf petioles, veins with swelling Petiole-gall aphids (Pemphigus spp.)
Leaves generally distorted and thickened Poplar vagabond aphid (Mordwilkoja vagabunda)
Affecting Stems, Twigs or Small Branches:
Signs or Symptoms Cause
Hollow swellings on new shoots Petiole-gall aphids (Pemphigus spp.)
Terminal leaves distorted into thickened mass Poplar vagabond aphid (Mordwilkoja vagabunda)
Twigs shredded in irregular row Cicada oviposition injury (Platypeisidae)
Swellings in twigs, small branches Poplar gall borer (Superda inornata) or Hail injury (upper surface only)
Scales on twigs, branches Oystershell scale (Lepidosophes ulmi)
Catkins grossly distorted and enlarged Cottonwood catkin gall mite (Eriophyes neoessigi)
Affecting Larger Branches or Trunks:
Signs or Symptoms                                Cause
Fungal fruiting bodies (mushrooms, conks) present Stem decay fungi (various species)
Open wounds, internal decay, swollen areas in stem  Stem decay fungi (various species)
Masses of caterpillars resting on bark Forest tent caterpillar (Malacosoma disstria)
Tunneling in trunk, often with orange staining ooze Cottonwood borer (Plectodera scalator),Poplar borer (Saperda calcarata),Cottonwood Crown Borer, or American hornet moth (Sesia tibialis)
Clear to white oozing or frothy malodorous liquid exiting from wounds Bacterial wetwood/slime flux
Areas of dead bark with discoloration and small pimple-like fruiting bodies (pycnidia) Cytospora canker (Valsa spp.,Leucostoma spp.)
Insects visiting oozing sap from trunk Flies (various families)
Affecting Roots and Ground Line Area:
Signs or Symptoms:                                          Cause:                                                                                                      
White root decay with white mycelial fans between bark and wood Armillaria root disease(Armillaria mellea)
Gall at ground line Crown gall (Agrobacterium tumefaciens)

 

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Potato

plant diagnostic_database

                            Potato (Solanum tuberosum)                          

Potato        

Affected Area:

                                                

Plant Information:

 

The potato is a starchy, tuberous crop that was introduced outside the Andes region four centuries ago, and have become an integral part of much of the world's cuisine. It is the world's fourth-largest food crop, following rice, wheat and maizePotato cultivars appear in a huge variety of colors, shapes, and sizes.  Potatoes require a loose, well-drained soil and plenty of sun.  Potatoes are sensitive to fluctuating soil moisture levels; if irrigation is not well distributed throughout the season, growth cracks and knobby tubers will result.  Potatoes are heavy feeders and require moderate to high levels of nitrogen, phosphorus, potassium, calcium and sulfur.  Plant certified seed when soil temperatures reach 40°F.

 

 

  • USDA Plants Database
  • Lady Bird Johnson Wildflower Center
Affecting Leaves and Stem:
Signs or Symptoms           Cause 
Large gray-brown spots with concentric rings; spots merge and cover entire leaf Early blight (Alternaria spp.)
Water-soaked brown lesions on lower leaves first Late blight (Phytophthora infestans)
Light-green to yellow leaves with lower leaflets rolled upwards Leaf roll virus
Yellow, mottled leaves accompanied by crinkling Mosaic virus
Yellow leaves, stem black below soil line Blackleg (Erwinia caratova)
Yellow, puckered, curled leaves Potato aphids
Yellow, stippled, stunted leaves Leafhoppers
Holes in leaves are large; whole leaflets consumed Colorado potato beetle (Leptinotarsa decemlineata)
Small holes in leaves Flea beetles (Phyllotreta spp.)
Affecting Whole Plant:
Signs or Symptoms Cause
Sprouts die before emergence Rhizoctonia (Rhizoctonia spp.)
Yellow, stunted plants Root-knot nematodes (Meloidogyne spp.)
Yellow leaves, gradual wilting usually at flowering Verticillium wilt (Verticillium spp.)
Plants wilt suddenly Wireworms
Affecting Tubers:
Signs or Symptoms                                Cause
Brown to black raised spots on potato Rhizoctonia (Rhizoctonia spp.)
Rough, raised lesions on potato Potato scab
Enlarging brown to black blotches on potato; internal tissue is brown and dry just below the surface Early blight (Alternaria spp.)
Tiny surface trails (or tunnels) just beneath potato skin Tuber flea beetle larvae (Phyllotretaspp.)
Dark, internal lesions on potatoes Phosphorus or potassium deficiency
Dwarfed potatoes Calcium deficiency
Green coloration of tubers Exposure to light. Keep developing tubers covered with soil.

 

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Privet

plant diagnostic_database

                            Privet (Ligustrum spp.)                          

Ligustrum        

Affected Area:
  • Leaves                              

Plant Information:

 

Privets are deciduous shrubs that are most widely used as hedges.  Privets all have clusters of white flowers in the spring followed by clusters of black fruit.  Privets are easily grown in most soils and prefer full sun to light shade.   Depending on species privets height range from 4-15'.

 

 

  • USDA Plants Database
  • Lady Bird Johnson Wildflower Center
Affecting Leaves:
Signs or Symptoms           Cause 
Edge of leaves cut in semicircle Leafcutter bees (Megachile spp.)
Edge of leaves notched Black vine weevil (Otiorhynchus sulcatus)
Leaves with blotchy mines Lilac leafminer (Caloptilia syringella)
Leaves blackened and wilted Bacterial blight (Pseudomonas syringaepv. syringae)
White powdery material on upper or lower surface of leaf Powdery mildew (Microsphaera penicillata)
Leaves turn a rusty color Rust mites
Affecting Stems, Twigs or Small Branches:
Signs or Symptoms Cause
Scales Oystershell scale (Lepidosaphes ulmi)
Borers Lilac/ash borer (Podosesia syringae)



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Pyracantha

plant diagnostic_database

                           Pyracantha (Pyracantha spp.)                          

Pyracantha        

Affected Area:
  • Leaves                              
  • Twigs and Smaller Branches                                             

Plant Information:

 

Pyracantha is an evergreen to semi-evergreen shrub in the Rosaceae family grown for their glossy green leaves and bright fruit.  Pyracantha grows fast with a upright to sprawling habit.  The thorny branches need regular pruning to keep them in good shape.  Used in the landscape as a hedge, topiary shape or ground cover.  Plant in full sun to part shade in well-drained soils.

 

 

  • USDA Plants Database
  • Lady Bird Johnson Wildflower Center
Affecting Leaves:
Signs or Symptoms           Cause 
Stippling of leaves Spider mites (Tetranychidae spp.)
Affecting Stems, Twigs or Small Branches:
Signs or Symptoms Cause
Twig blight/dieback Fireblight (Erwinia amylovora)



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Rabbitbrush

plant diagnostic_database

                          Rabbitbrush (Chrysothamnus spp.)                          

Chrysothamnus        

Affected Area:
  • Leaves                              

Plant Information:

 

Rabbit-brush are shrubs whose flexable branches are covered with felt-like hairiness.  Rabbit-brush grows in dry open habitats in the valleys and foothills.  Shrubs range in height from 3-5'.  Clusters of yellow flowers appear in the late summer or fall.  American Indians used rabbit-brush to make chewing gum, tea, cough syrup, and yellow dye. The rubbery twigs were used in making baskets.

 

 

  • USDA Plants Database
  • Lady Bird Johnson Wildflower Center
Affecting Leaves:
Signs or Symptoms           Cause 
Leaves chewed Snailcase bagworm (Apterona helix)
White powdery material on upper or lower surface of leaf Powdery mildew
Orange pustules on leaf Leaf rust
Affecting Stems, Twigs or Small Branches:
Signs or Symptoms Cause
Frothy mass on stems Spittlebug (Clastoptera spp.)
Cottony balls on stems Rabbitbrush gall flies (Aciurina bigeloviae)
Green flowerlike swellings Rabbitbrush gall flies (Aciurina bigeloviae)



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Radish

plant diagnostic_database

                         Radish (Raphanus sativus)                          

Radish        

Affected Area:
  • Leaves                              
  • Roots                                             

Plant Information:

 

There are two main types of radishes - the regular small and quick maturing and the winter ones which are larger and more pungent.  Most commercial varieties are red but radishes can be white, red & white and purple-black.  Radishes like cool, moist growing conditions.  They can germinate and grow at 40°F, but optimum temperatures are 50-65°F.  Water heavily for the first two weeks after emergence.

 

 

  • USDA Plants Database
  • Lady Bird Johnson Wildflower Center
Affecting Leaves:
Signs or Symptoms           Cause 
Yellow v-shaped spots on leaf margins with blackened veins Black rot (Xanthomonas campestris
Yellowish leaves, lower leaves drop; stunted plants may have twisted stems; usually occurs soon after transplanting Fusarium yellows (Fusarium oxysporum)
Yellow leaves, older first; stunted plants Nitrogen deficiency
Yellow, curled leaves; stunted plants Aphids
Purplish patches on leaves Phosphorus deficiency in cool soils
Small leaf holes Flea beetles (Phyllotreta spp.)
Large leaf holes Cabbage Loopers or Imported Cabbage Worms (Pieris rapae)
Affecting Roots:
Signs or Symptoms Cause
Yellow, stunted plants that wilt during bright, hot days and recover at night Root injury. Check for root maggots.
Small, imperfectly formed roots Nitrogen deficiency
Poor root development Phosphorus deficiency
White spots or streaks internally; large air spaces and tough, dry roots High temperature injury
Soft, shriveled roots Freezing injury



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Raspberry

plant diagnostic_database

                        Raspberry (Rubus spp.)                          

Raspberry        

Affected Area:

Plant Information:

 

Raspberries are easy to grow shrubs with biennial canes.  The canes that have fruit on them in the second year then die with new canes sprouting up to take their place.  Raspberries can be red, yellow or black in color.  There are everbearing which fruit ripens on 2 year canes in summer and on the top of new first year canes in the fall, and the summerbearing which ripen early to midsummer on the second year canes. 

Raspberries need full sun and a well-drained soil with lots of organic matter in it. 

 

  • USDA Plants Database
  • Lady Bird Johnson Wildflower Center
Affecting Leaves:
Signs or Symptoms           Cause 
New leaves and shoots have a powdery appearance.  Later, light brown to orange pinhead-sized balls form within the mass of white growth. These tiny dots mature and turn a black color. These black structures are the overwintering stage. Powdery Mildew
Leaves on infected plants are uniformly small, dark green, crinkled, and tightly curled downward and inward. When diseased shoots first appear, they are pale yellowish-green, but they soon turn dark green, become stiff and brittle, and usually do not branch.Plant lose vigor each year. Berries on infected plants may ripen prematurely and are small, dry, seedy, and crumbly.   Raspberry Leaf Curl Virus.  Infected plants should be destroyed immediately.
Affecting Twigs and Smaller Branches:
Signs or Symptoms Cause
Larvae bore many tunnels in canes and the crown may be extensively damaged Raspberry Crown Borer
Affecting Roots and Ground Line Area:
Signs or Symptoms Cause
The most obvious symptoms of root rot are stunted, yellowing leaves, premature fall coloration and leaf drop, and twig and branch dieback. By the time the foliar symptoms develop, the rot canker may extend halfway or more around the stem of the plant. In early stages, the diseased bark is firm and intact while the inner bark is slimy and may produce a moist, gummy exudate.  Phytophthera Root Rot
Affecting Fruit:
Signs or Symptoms Cause
Worm Like grubs inside raspberries
Prune out old canes as soon as they fruit and cultivate around plants 

The adults cause characteristic slits in the leaves from their feeding and destroy developing buds. 
The larvae feed within the blossoms and inside developing fruit.
Western Raspberry Fruitworm
Affecting Whole Plant:
Foliar symptoms typically include wilting, curling, yellowing, marginal or interveinal browning or death. Often these symptoms may look like water stress and can occur on only one side of the plant. Other symptoms may include dieback of branches or a portion of the plant. Furthermore, wood under the bark may exhibit discolored streaks or bands. The color of the streaks can range from light tan to grayish olive to brownish-black. Yellowing and defoliation often progress upward. Verticillium Wilt
Brown, irregular, blotchy area that expands between leaf veins. 

Black, sunken spots develop on fruits, leaves, and stems of vegetables.
Anthracnose


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Rhubarb

plant diagnostic_database

                       Rhubarb (Rheum rhaponticum)                          

Rhubarb        

Affected Area:
  • Leaves                             
  • Stalks                                        

Plant Information:

 

Rhubarb is a hardy perennial grown for its red and green stemmed stalks.  The stalks are topped with dark green leaves that are poisonous.  Rhubarb prefers a pH of 6-6.8 and a deep, sandy, well drained soil high in organic matter.  Mulch with several inches of high nitrogen compost each spring and water the mulch down well.  Do not over harvest, so the plant will not be stressed.  Harvest rhubarb by grasping each stalk near its base and giving it a sideward twisting tug.  Canada red and honeyred are good red stalk varieties.

 

 

  • USDA Plants Database
  • Lady Bird Johnson Wildflower Center
Affecting Leaves:
Signs or Symptoms           Cause 
Yellow, curling leaf margins, wilted plants Leaf hoppers
Yellow leaves, slow growth Nitrogen deficiency
Wilting, yellow leaves, marginal leaf browning Verticillium wilt (Verticillium spp.)
Small, round, brown spots on leaves Fungal disease
Affecting Stalks:
Signs or Symptoms Cause
Holes chewed in stalks Worms, including European corn borer(Ostrinia nubilalis) and Imported Cabbage worm(Pieris rapae)

 


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Rose

plant diagnostic_database

                    Rose (Rosa spp.)                          

Rosa        

Affected Area:
  • Leaves
  • Canes                             
  • Flowers                                        

Plant Information:

 

A rose is a woody perennial of the genus Rosa, within the family Rosaceae. There are over 100 species. They form a group of plants that can be erect shrubs, climbing or trailing with stems that are often armed with sharp prickles. Flowers vary in size and shape and are usually large and showy, in colors ranging from white through yellows and reds. Most species are native to Asia, with smaller numbers native to Europe, North America, and northwest Africa. Species, cultivars and hybrids are all widely grown for their beauty and often are fragrant. Rose plants range in size from compact, miniature roses, to climbers that can reach 20 feet in height. Different species hybridize easily, and this has been used in the development of the wide range of garden roses

 

 

  • USDA Plants Database
  • Lady Bird Johnson Wildflower Center
Affecting Leaves:
Signs or Symptoms           Cause 
White powdery material on upper or lower surface of leaf Powdery mildew (Sphaerotheca pannosa)
Leaves with white spotting Rose leafhopper (Edwardsiana rosae) orTwospotted spider mite (Tetranychus urticae Koch) or Rust (Phragmidium mucronatum)
Small ball-like growths on leaves, usually reddish Gall wasps 
Leaves mottled with yellowish areas Iron chlorisis or Rose mosaic complex(various viruses are responsible)
Orange-red colored patches on lower leaf surface Rose rust
Angular brown spots on leaves Anthracnose
Interior areas of leaves chewed Roseslug and other sawflies (Endelomyia aethiops)
Even, semicircular cuts in leaf edge Leafcutter bees (Megachile spp.)
Leaves curled Powdery mildew or Aphids
Dark spots on leaves Black spot (Diplocarpon rosae)
Affecting Canes:
Signs or Symptoms Cause
Insects tunneling into pith of cane Leafcutter bees (Megachile spp.)
Exterior area of cane girdled, sometimes with associated dieback Bronze cane borer / Rose stem girdler(Agrilus aurichalc)
Mossy or ball-like growths on stem Gall wasps (Diplolepsis sp.) 
Woody, tumor-like growth, usually on lower stem Crown gall (Agrobacterium tumefaceins)
Swellings in canes, often with associated vertical cracking Bronze cane borer / Rose stem girdler(Agrilus aurichalceus)
Purple to tan, sometimes sunken spots on canes  Rose canker (Cryptosporella orLeptosphaeria sp.)
Affecting Flower:
Signs or Symptoms Cause
Flower buds killed, fail to emerge (blind shoots) Rose midge (Dasineura rhodophaga); Fluctuating, cool temperatures; or Rose curculio (Merhynchites bicolor)
Flower petals scarred  Flower thrips (Thysanoptera spp.)
Flower petals chewed or tunneled Earwigs (Forficula auricularia L.), Rose curculio (Merhynchites bicolor)
Flowers produced are off-type after winter (Grandiflora and hybrid tea roses) Die back to the grafted rootstock

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Serviceberry

plant diagnostic_database

                     Serviceberry (Amelanchier spp.)                          

Amelanchier        

Affected Area:
  • Leaves                             
  • Twigs                                       

Plant Information:

 

Serviceberry are deciduous shrubs or small trees also called juneberry or saskatoons.  They produce drooping clusters of white flowers in early spring which form dark blue fruits, popular with birds.  Serviceberry grows best in full sun to part shade and is tolerant of many soils as well as they are well drained.

 

 

  • USDA Plants Database
  • Lady Bird Johnson Wildflower Center
Affecting Leaves:
Signs or Symptoms           Cause 
Orange leaf spots, defoliation and fruit and twig deformities. Cedar Apple Rust
Affecting Twigs:
Signs or Symptoms Cause
Twigs in short thick clumps Witches broom (Apiosporina collinsii)

 

Spinach

plant diagnostic_database

                    Spinach (Spinacia oleracea)                          

Spinach        

Affected Area:
  • Leaves                           
  • Whole plant                                      

Plant Information:

 

Spinach is a cool season crop that can be grown in the spring and fall and overwintered.  There are two different leaf forms crinkled (savoy) and flat leaf.  Spinach prefers temperatures of 60-65°F and is unhappy when temperatures reach 75° which causes them to bolt (form seed heads).  Soils with good drainage and high organic matter are preferred.  Spinach is a heavy nitrogen feeder with moderate levels of phosphorus and potassium required.

 

 

  • USDA Plants Database
  • Lady Bird Johnson Wildflower Center
Affecting Leaves:
Signs or Symptoms           Cause 
Yellow area on leaf upper surface with blue-gray patches on undersides of leaves Downy mildew (Peronospora effusa)
Young center leaves turn yellow and curl, followed by mottling, browning, and death of larger leaves Tobacco Mosaic Virus
Yellow deformed leaves that eventually die, along with stunted plants Curly-top
Yellow curled leaves and stunted growth Aphids, usually green peach aphids
Light-colored winding tunnels in leaves; becomes an enlarged blotch at the ends of leaves which may turn white or brown Spinach leaf miner
Small holes in leaves, undersides of leaves may be skeletonized Flea beetles (Phyllotreta spp.)
Ragged holes in outer leaves, usually between leaf veins Cabbage looper and/or Beet armyworm
Affecting Whole Plant:
Signs or Symptoms Cause
Seeds do not germinate; a poor stand despite using fresh seed and maintaining proper germination conditions Damping off Pythium, Rhizoctonia, and other fungi)
Young plants stunted and yellow along with gradual wilting of older plants Fusarium wilt (Fusarium oxysporum)

 

Spirea

plant diagnostic_database

                     Spirea (Spiraea spp.)                          

Spiraea        

Affected Area:

                               

Plant Information:

 

Spirea are deciduous shrubs that come in various shapes and sizes with flower colors of pink, red and white.  Easy to grow in all kinds of soils, in sun or light shade, and average water.  Form, height, leaf color and flowering season vary between varieties.  Spirea has very few pests attacking it including deer.

 

 

  • USDA Plants Database
  • Lady Bird Johnson Wildflower Center
Affecting Leaves:
Signs or Symptoms           Cause 
Insect on leaves, sometimes associated with leaf curls Spirea aphid (Aphis citricola)

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Spruce

 

 

plant diagnostic_database

                            Spruce (Picea spp.)                          

Picea        

Affected Area:

Plant Information:

Spruce are evergreen trees and shrubs that have many varieties of shapes and sizes.  They are large pyramidal or cone shaped trees or dwarf forms that are useful in foundation plantings, rock gardens and containers.  Spruce are used extensively in large scale landscape plantings such as parks, golf courses, highways, and public buildings.  Spruce have a shallow, spreading root system allowing them to be transplanted as a large specimen easily.  They prefer a moderately moist well-drained soil but can adapt to clay soils as well.  Spruce trees are used for pulp and paper manufacturing as well as their pitch being used as a compound for varnishes and medicinal compounds.

 

 

Affecting Needles:
Signs or Symptoms      Cause
New needles being chewed Douglas-fir tussock moth (Orgyia pseudotsugata) or Western spruce budworm (Choristoneura occidentalis)
Needles chewed and fragments tied with webbing Spruce needleminer (Endothernia albolineana)
Brown felt-like material on needles, branches (high elevation) Brown felt blight (Herpotrichia juniperi) or Snow mold
Needles being mined Spruce needleminer (Endothenia albolineana)
Aphids on needles Giant conifer aphids (Cinara spp.)
Needles become grayish, with small flecks Spruce spider mite (Oligonychus ununguis)
White scales on needles Pine needle scale (Chionaspis pinifoliae)
Brown needles with dark fruiting bodies Needlecasts (Lophodermium sp. and others)
Needles to exterior of tree bleached or brown, developing late winter Winter dessication
Needles on branch turn reddish brown Cytospora canker (Valsa spp.,Leucostoma spp.) or Root injury
Mottled yellowing of needles on a branch Winter exposure injury
Affecting Twigs and Smaller Branches:
Signs or Symptoms Cause
Twigs distorted into cone-like gall Cooley spruce gall adelgid (Adelges cooleyi)
Woolly aphid on underside of twigs in spring Cooley spruce gall adelgid (Adelges cooleyi)
Small bud-like scales on twigs Spruce bud scale
Large aphids on branch Giant conifer aphids (Cinara spp.)
Resinous canker on branch Cytospora canker (Valsa spp.,Leucostoma spp.)
Affecting Larger Branches or Trunk:
Signs or Symptoms Cause
Bark beetles Spruce beetle (Dendroctonus rufipennis) or Spruce ips (Ips hunteri Swaine)
Aphids Giant conifer aphids (Cinara spp.)
Open wounds, internal decay, swollen areas in stem Stem decay fungi (Phellinus pini,Inonotus circinatusFomitopsis pinocolaand various fungal genera)
Fungal fruiting bodies (mushrooms, conks) present Stem decay fungi (Phellinus pini,Inonotus circinatusFomitopsis pinocolaand various fungal genera)
Affecting Top of Tree:
Signs or Symptoms Cause
Wilting and dieback restricted to terminal, shepherds' crook White pine weevil (Pissodes strobi)
Upper crown defoliated Douglas-fir tussock moth (Orgyia pseudotsugata)
Upper crown dieback Spruce ips (Ips hunteri Swaine)
Affecting Roots:
Signs or Symptoms Cause
White root decay with white mycelial fans between bark and wood Armillaria root disease (Armillaria mellea)


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Squash

 

 

plant diagnostic_database

                              Squash (Cucurbita spp.)                          

Squash        

Affected Area:

Plant Information:

There are four species of squash which are divided into summer and winter types in more shapes and colors than most gardeners will ever have the room to grow.  Summer squashes are eaten in immature stages while winter squashes are utilized when fruits are mature.  Squash insist upon full sun and warm temperatures >60°F.  Squash prefer well-drained soils with lots of organic matter.  Keep squash well watered as they have a very shallow root system supporting a large mass of leaves.  Each squash produces both male and female flowers separately on the same plant, so pollination is essential for good production.

 

 

Affecting Leaves and Vines:
Signs or Symptoms      Cause
Plants wilt, foliage looks burned; preceded by pale green areas forming on leaves Squash bug (Anasa tristus)
Sudden wilting of a runner or part of a runner Squash vine borer (Melitta satyriniformis)
Leaves wilt, yellow, and curl High Aphid populations
Vines wilt and die gradually, starting with newer leaves; no leaf yellowing is present Bacterial wilt (Erwinia tracheiphila)
Small, pitted leaf holes on young plants Cucumber beetles (Acalymma vittata)
Distorted, Yellow spots on leaves with mottling and wrinkling of older leaves Mosaic viruses
Older leaves mottled yellow between veins Downy mildew (Peronospora effusa)
Powdery, white spots on upper surface of leaves especially Powdery mildew
Leaf spots that begin as water-soaked, then turn gray, die and drop out leaving foliage with a shot-hole appearance Angular leafspot (Pseudomonas syringae)
If water-soaked, yellow spots turn brown Anthracnose
Leaves are yellow and puckered and become bronzed Mites
Dark brown spots with concentric rings on older leaves first; vines defoliate eventually Alternaria leaf blight (Alternaria spp.)
Spots with pale, round centers and dark margins on upper surface of leaves Cercospora leaf spot (Cercospora spp.)
Affecting Fruit:
Signs or Symptoms Cause
Small, brown, angular fruit spots Angular leafspot (Pseudomonas syringae)
Brown and sunken zoned spots Alternaria (Alternaria spp.)
Circular, black, sunken cankers Anthracnose
Misshapen, yellow mottled fruit, often with a bitter taste Mosaic virus
Fruit wilts and shrivels Bacterial wilt (Erwinia tracheiphila)
Fruit is narrow at stem end Potassium deficiency
Fruit has a dull bronze color Phosphorus deficiency
Fruit is light colored Nitrogen deficiency
Dark pitting of fruit Cold damage


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Stone Fruits

plant diagnostic_database

Stone Fruits:  Apricot, Cherry Chokecherry, Peach, Plum, etc.

(Prunus spp.) 

Prunus

Affected Area:

Plant Information:


The genus Prunus is comprised of nearly 200 species of five subgenera:  plums and apricots, almonds and peaches, umbellate cherries, deciduous racemose cherries, and the evergreen racemose cherries.  The species of this genus range from shrubs to trees over 90 ft. tall.  Over 100 species have been cultivated as either ornamentals or as food crops.  Trees for fruit production and many ornamentals are generally propagate by budding or grafting, while seed propagation is reserved for generation of rootstocks and breeding programs.  The most common rootstock:scion combinations are:  almond:almond and plum; apricot:apricot; mazzard cherry:sweet cherry; mahaleb cherry:sweet and sour cherry; peach:peach, almond, apricot, plum; American plum:plum in cold regions; Bessey cherry:dwarf peaches. 

 

Affecting Whole Plant:
Signs or Symptoms Cause 
Tree decline in vigor Phytophthora root rot (Phytophthoraspp.), Cytospora Canker (Valsa spp.,Leucostoma spp.), or Verticillium wilt(Verticillium spp.)
Affecting Leaves:
Signs or Symptoms Cause 
Leaves chewed, no associated webbing Pearslug (Caliroa derasi)
Upper surface of the leaf skeletonized Pearslug (Caliroa cerais) or Apple Thorn Skeletonizer
Webbing associated with chewing Fall webworm (Hyphantria cunea Drury),Ugly Nest caterpillar (Archips cerasivorana), or Western tent caterpillar(Malacosoma californicum)
Leaves with small, circular holes Shot hole disease 
White flecking injuries  White apple leafhopper (Typhlocyba pomaria McAtee) or Lacebug (Corythuca padi), on chokecherry (Corythuca spp.)
White powdery material on upper or lower surface of leaf Powdery mildew
Leaves yellow Iron chlorosis or X-disease
Leaves with small, pouch or finger-like projections Fingergall mites (Phytoptus species)
New leaves curled Aphids: Green peach aphid (Myzus persicae), Leafcurl plum aphid (Anuraphis helichrysi), or Black cherry aphid (Myzus cerasi)
New leaves curled and thickened and red/purple Peach leaf-curl disease
Affecting Larger Branches or Trunks:
Signs or Symptoms Cause 
Black galls on branches Black knot of cherry (Apiosporina morbosa) 
Stem decay and/or hoof-shaped fruiting body (conk) Decay fungus (Phellinus pomaceus)
Scales Scale: European fruit lecanium (Parthenolecanium corni) or Oystershell scale (Lepidosaphes ulmi)
Small pinhead-sized exit holes in branches Shothole borer (Scolytus rugulosus)
Branches die back Cytospora canker (Valsa spp.,Leucostoma spp.) or Shothole borer (Scolytus rugulosus)
Gumming and dark colored branches Shothole borer (Scolytus rugulosus), or Cytospora canker (Valsa spp.,Leucostoma spp.) or Bacterial Blight (Pseudomonas syringae)
Dead bark with discoloration and small pimple-like fruiting bodies (pycnidia) Cytospora canker (Valsa spp.,Leucostoma spp.)
Wilting and dieback of portions of tree, originating from roots Verticillium wilt (Verticillium spp.)
Affecting Ground Line Area of Trunk:
Signs or Symptoms Cause 
Discolored tissue under bark at ground line Phytophthora root rot (Phytopthora sp.)
Gall at ground line Crown gall (Agrobacterium tumefaciens)
Affecting Fruit:
Signs or Symptoms Cause 
Fruit tunneled European earwig (Forficula auricularia L.)
Fruit with sunken, corky areas Plant bug (Lygus species), Hail injury, or Boxelder bug (Boisea trivittata)
Puncture wounds in fruit Bird damage (Robins, finches, etc.)
Chokecherry fruit enlarged, hollow Chokecherry gall midge (Contarinia virginianae)
Maggots in cherry fruit Western cherry fruit fly (Rhagoletis indifferens Curran

 

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Strawberry

 

 

plant diagnostic_database

                             Strawberry (Fragaria spp.)                          

Strawberry        

Affected Area:

Plant Information:

Strawberries, one of the easiest fruits to grow, in the ground, containers, or hanging baskets.  There are many varieties in the three types:  june-bearing - produces one crop per year, everbearing - produces two crops per season, day-neutral - produces all season long.  June-bearing are the most common and thought to be the best tasting.  Strawberries like full sun and well drained soils that are high in organic matter.  The strawberry propagates itself by sending out runners (stolons) from buds in the plants crown which will root new plants. Most strawberry beds need to be renovated with new plants every 3 years to keep the planting in peak production

 

Affecting Leaves:
Signs or Symptoms      Cause
Yellow, distorted leaves. Aster yellows virus
Small, deep purple, round to elongate spots on leaves and sometimes on fruit. Spots enlarge and develop light-colored centers.    Relative humidities of 98-100% and temperatures of 59 to 77º F promote infection. Middle-aged leaves appear to be most susceptible. Plant on raised beds and avoid sprinkler irrigation. Common leaf spot (Mycosphaerella fragariae).
Yellow stippled to bronzed-colored leaves. Spider mites
White frothy areas on leaves and stems. Spittle bugs
Affecting Fruit:
Signs or Symptoms Cause
Senescent leaves, fruits, and petals are susceptible. Under cool (60 - 70° F.), moist conditions a soft, brown decay develops, covered by a dense gray to light brown mass of spores. Gray Mold (Botrytis cenerea)


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Sumac

plant diagnostic_database

                     Sumac (Rhus spp.)                          

Rhus        

Affected Area:
  • Leaves
  • Twigs                             

Plant Information:

 

Sumacs are deciduous shrubs or small trees in our area.  Sumacs are very hardy and thrive in poor soils.  They tend to sucker and spread into large colonies if left unchecked.  A large, loose spreading habit with  many toothed leaflets that turn a brilliant scarlet/orange color in the fall.  Several varieties common to the area such as staghorn which gets its name for the short brown hairs that covers the stems resembling deer's antlers in velvet. 

 

  • USDA Plants Database
  • Lady Bird Johnson Wildflower Center
Affecting Leaves:
Signs or Symptoms           Cause 
Small reddish swellings Eriophyid mite gall
Affecting Twigs:
Signs or Symptoms Cause
Dark insects on twigs Oystershell scale (Lepidosaphes ulmi)
Affecting Stems and Branches:
Signs or Symptoms Cause
Discolored areas, dead bark containing small pinmple-like fruiting bodies (pycnidia) Cytospora canker (Valsa spp.,Leucostoma spp.)
Wilting and dieback of portions of plant originating from roots Verticillium wilt (Verticillium spp.)

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Sycamore

plant diagnostic_database

                   Sycamore (Platanus spp.)                          

Platanus        

Affected Area:

Plant Information:

Sycamores are fast growing large trees with lobed maple-like leaves.  Brown, ball like seed clusters hang from branches through the winter.  Easily transplanted; prefers deep rich, moist, well-drained soils but will grow in about anything.  Older bark sheds in patches to reveal pale, smooth, new bark beneath.  Sycamores are good for large areas such as parks and open spaces, but not in small yards and along streets. The variety "bloodgood" has some resistance to anthracnose

 

 

  • USDA Plants Database
  • Lady Bird Johnson Wildflower Center
Affecting Leaves:
Signs or Symptoms           Cause 
Leaves with blackened spotting Anthracnose (Apiognomonia veneta)
Affecting Twigs and Smaller Branches:
Signs or Symptoms Cause
Discolored areas, dead bark containing small pinmple-like fruiting bodies (pycnidia) Cytospora canker (Valsa spp.,Leucostoma spp.)
Witches' broom with dead small branches Anthracnose (Apiognomonia veneta)
Affecting Larger Branches or Trunk:
Signs or Symptoms Cause
Discolored areas, dead bark containing small pinmple-like fruiting bodies (pycnidia) Cytospora canker (Valsa spp.,Leucostoma spp.)
Clear to white oozing or frothy malodorous liquid Bacterial wetwood / Slime flux

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Tomato

plant diagnostic_database

                  Tomato (Lycopersicon esculentum)                          

Tomato        

Affected Area:
  • Fruit                                       

Plant Information:

 

One of the most popular grown garden plants, tomatoes will be prolific producers if given a warm, sunny location with rich, well drained soils.  There are two main types to choose from.  Determinant types grow to a certain height and stop, putting all their energy into producing fruit over a 4-6 week period.  Indeterminant types continue to grow, producing new fruiting clusters all season long.  Tomatoes grow best at temperatures of 65-95° F.  There are many varieties such as paste, cherry, patio, slicing, hybrid, heirloom and many colors to choose from.  Pick varieties suitable to your climate and growing season.

 

 

  • USDA Plants Database
  • Lady Bird Johnson Wildflower Center
Affecting Leaves and Stems:
Signs or Symptoms           Cause 
Young leaves turn yellow between veins Iron deficiency, usually on soils with high pH 
Younger leaves pale, terminal buds die Calcium deficiency
Leaves on young plant are purple Phosphorus deficiency
Older leaves pale, small, general yellowing Nitrogen dificiency
Older leaves turn yellow between veins while veins remain green, then become bronzed Potassium deficiency
Yellow, mottled leaves; curling and malformation giving terminals a fernlike appearance Mosaic virus
Black to brown angular to circular small spots (without concentric zones). Bacterial Spot
Brown spots, distorted leaves and stems; stunted and sticky leaves covered with a black film Aphids 
Leathery, black-brown spots with concentric rings; lower leaves and stems affected first; occurs during humid/wet, warm conditions Early Blight
Black-green water soaked areas on older leaves, branches, and stems, usually in humid/wet cooler weather (60-70° F.) Late Blight 
Small to large round holes in leaves, plants and leaflets stripped Colorado Potato Beetle
Whole leaves consumed Tobacco hornworms
Small pitted holes, shot-hole injury Flea beetles (Phyllotreta spp.)
Leaves have irregular chew holes giving the leaves a ragged appearance  Cabbage Looper 
Affecting Whole Plant:
Signs or Symptoms Cause
Yellowing and flagging of shoots and leaves at base of plant first. Cross section of infected stem has reddish-brown vascular system. Occurs when temperature is 80-90° .F Fusarium wilt 
Yellowing and gradual wilting; leaf margins curl upwards; light brown discoloration of vascular system. Occurs at 68-75° F. Verticillium Wilt
Young plants cut off at soil line Cutworms
Whole plant yellows, wilts and dies. Check roots. If galls on roots up to 1 inch in diameter,Root-knot nematodes
Affecting Fruit:
Signs or Symptoms Cause
Large chunks of green fruit consumed Tobacco and tomato hornworm or Colorado potato beetle
Small holes on fruit surface with a messy, watery, rotten internal cavity. Fruit appears to collapse like a balloon Tomato fruitworm, also called Corn earworm
Dark pinpricks surrounded by light areas; white, spongy area below spots Stink bugs
Scarring and malformation of fruit, especially at blossom end Catfacing
Yellow or white blister-like patch on fruit, usually on side exposed to the sun