← Back to Library

Diseases

388 diseases tracked across Western Washington landscapes, with host plants, symptoms, and management.

Data collection is ongoing. Profiles deepen as symptoms, management strategies, GDD thresholds, and regional notes are verified from extension research.

Showing 388 diseases
Alkali Yellows
Alkali yellows
Affects 2 plants
Alternaria Fruit Rot
Alternaria spp
Affects 12 plants
Alternaria Leaf Spot
Alternaria spp.
Affects 1 plant
Annosus Root Rot
Heterobasidion annosum (syn. Fomes annosus)
Affects 20 plants
Anthracnose
Colletotrichum acutatum complex (C
Affects 180 plants
Anthracnose (Bull's-eye Rot)
Cryptosporiopsis curvispora
Affects 16 plants
Anthracnose and Bull's-eye rot
Neofabraea spp. (N
Affects 13 plants
Anthracnose Blotch
Ophiognomonia leptostyla (syn. Gnomonia leptostyla)
Affects 5 plants
Apple Mosaic
Apple mosaic
Affects 12 plants
Apple Proliferation
Apple proliferation
Affects 12 plants
Armillaria Crown and Root Rot
Armillaria mellea
Affects 36 plants
Armillaria Root Rot
Armillaria ostoyae
Affects 466 plants
Ascospora Dieback
Seimatosporium lichenicola
Affects 14 plants
Aspen Trunk Rot
Daldinia concentrica
Affects 11 plants
Bacterial Blight
Pseudomonas syringae pv. syringae
Affects 122 plants
Bacterial blight (Leaf spot)
Pseudomonas syringae pv. viburni or Xanthomonas spp.
Affects 31 plants
Bacterial Blights
Pseudomonas syringae
Affects 0 plants
Bacterial Cane Blight
Affects 8 plants
Bacterial Canker
Pseudomonas syringae pv. syringae
Affects 51 plants
Bacterial Canker and Blast
Pseudomonas syringae pv. syringae
Affects 36 plants
Bacterial Leaf Spot
Xanthomonas spp.
Affects 7 plants
Bacterial Leaf Spot and Blast
Pseudomonas syringae
Affects 8 plants
Bacterial Leaf Spot and Dieback
Pseudomonas syringae
Affects 45 plants
Bacterial Leaf Spot and Stem Canker
Xanthomonas hortorum pv. hederae
Affects 2 plants
Bacterial Leaf Spots
Pseudomonas syringae
Affects 0 plants
Bacterial twig blight
Pseudomonas syringae (bacterial)
Affects 14 plants
Bacterial Wetwood
Enterobacter cloacae and Klebsiella pneumoniae
Affects 8 plants
Bacterial Wetwood Slime Flux
Enterobacter cloacae
Affects 8 plants
Bacterial Wilt
Corynebacterium sepedonicum
Affects 2 plants
Basal Rot (Bulb Rot)
Fusarium spp.
Affects 1 plant
Berckmann's Blight
Hendersonia coniothyrium
Affects 3 plants
Bigleaf Maple Decline (Bigleaf Maple Dieback)
Affects 45 plants
Bitter Pit
Non-pathogenic (calcium deficiency)
Affects 13 plants
Black Canker
An uncharacterized
Affects 36 plants
Black Canker (Target Canker)
Ceratocystis fimbriata (black canker); Cytospora notastro...
Affects 11 plants
Black Knot
Apiosporina morbosa
Affects 38 plants
Black Mold
Chlaropsis thielavioides
Affects 12 plants
Black Root Rot
Thielaviopsis basicola
Affects 42 plants
Black Spot
[NOTE: Diplocarpon rosae causes black spot on roses (Rosa...
Affects 11 plants
Black Walnut Toxicity
Abiotic (juglone)
Affects 6 plants
Black-Stain Root Disease
Leptographium wageneri
Affects 4 plants
Blackleaf
Chalara spp., Asterina spp., Diplotheca spp.
Affects 2 plants
Blackline
Blackline virus
Affects 6 plants
Bleeding Canker
Phytophthora spp. (P
Affects 45 plants
Blister Rust
Cronartium ribicola
Affects 10 plants
Boron Deficiency
Many commercial
Affects 19 plants
Botryosphaeria Dieback
Botryosphaeria dothidea
Affects 134 plants
Botrytis Blight
Botrytis cinerea
Affects 48 plants
Botrytis Bud and Twig Blight
Botrytis cinerea
Affects 19 plants
Botrytis Bunch Rot
Botrytis cinerea
Affects 2 plants
Botrytis Bunch Rot Gray Mold
“Botrytis cinerea”
Affects 2 plants
Botrytis Petal Blight
Botrytis cinerea
Affects 137 plants
Botrytis Shoot Blight
Botrytis cinerea
Affects 164 plants
Box Blight
Calonectria pseudonaviculata
Affects 6 plants
Boxwood Blight
Boxwood blight
Affects 4 plants
Branch Canker
Various fungi (Phoma spp., Phomopsis spp., Cytospora spp....
Affects 69 plants
Brand and Common Canker
Two fungi
Affects 8 plants
Brand canker
Kalmusia coniothorium
Affects 10 plants
Break Viruses
Little Cherry Virus-1 and Little Cherry Virus-2
Affects 3 plants
Brittle Decay
Kretzschmaria deusta
Affects 45 plants
Broom Rust
Gymnosporangium libocedri
Affects 16 plants
Brown Canker
Cryptosporella umbrina (anamorph: Diaporthe umbrina)
Affects 8 plants
Brown Rot
Monilinia fructicola and M
Affects 37 plants
Brown Rot Blossom Blight and Fruit Rot
The fungi
Affects 38 plants
Bud Blight
Seifertia azaleae
Affects 132 plants
Bud Failure
Abiotic or viral
Affects 16 plants
Bull's-eye Rot
Cryptosporiopsis curvispora
Affects 12 plants
Bullhead
Non-pathogenic (physiological — cold damage during flower...
Affects 14 plants
Burrknot
Non-pathogenic (genetic/physiological)
Affects 13 plants
Cane and Leaf Spot
Sphaerulina westendorpii (formerly Septoria rubi) on Rubu...
Affects 2 plants
Cane Blight
Kalmusia coniothyrium
Affects 15 plants
Canker
Symptom category — not a single disease
Affects 122 plants
Cedar Flagging
Abiotic (natural leaf senescence and stress responses)
Affects 17 plants
Cercospora Leaf Spot
Cercospora hydrangeae Ellis & Everh
Affects 1 plant
Charcoal Rot
Macrophomina phaseolina
Affects 2 plants
Chemical Injury
Abiotic
Affects 22 plants
Cherry Mottle Leaf
Cherry mottle leaf virus
Affects 36 plants
Cherry Twisted Leaf
Cherry twisted leaf-associated virus
Affects 36 plants
Chestnut Blight
Cryphonectria parasitica (syn. Endothia parasitica)
Affects 3 plants
Cold Injury
Abiotic
Affects 3 plants
Collar Rot
Phytophthora cactorum
Affects 37 plants
Common And Yellow Mosaics
Bean common mosaic virus and Bean yellow mosaic virus
Affects 3 plants
Common canker
Coniothyrium wernsdorffiae and Paraconiothyrium fuckelii
Affects 10 plants
Common Leaf Spot
Ramularia grevilleana
Affects 4 plants
Coniophora Growth
Fungal growth
Affects 3 plants
Cork Spot
Non-pathogenic (calcium deficiency)
Affects 4 plants
Cottonball
Abiotic (symptom)
Affects 13 plants
Crinkle Leaf and Deep Suture
Believed to
Affects 36 plants
Crown and Cane Gall
Agrobacterium tumefaciens
Affects 14 plants
Crown and Collar Rot
Phytophthora cactorum (primary), P
Affects 13 plants
Crown and Root Rot
Phytophthora spp. (P
Affects 2 plants
Crown Gall
Rhizobium radiobacter (formerly Agrobacterium tumefaciens)
Affects 125 plants
Crown Rot
The fungal
Affects 5 plants
Crumbly Fruit
Raspberry bushy dwarf virus (RBDV) + raspberry leaf mottl...
Affects 14 plants
Cucumber mosaic virus
Cucumber mosaic virus
Affects 1 plant
Curly Top
Beet curly top virus
Affects 2 plants
Curly top (Beet curly top virus)
Beet curly top virus
Affects 4 plants
Current-season Needle Necrosis
[VERIFY]
Affects 15 plants
Cutting Rots
Rhododendron and
Affects 141 plants
Cyclaneusma Needle Cast
Cyclaneusma minus
Affects 42 plants
Cylindrocarpon Root Rot
Cylindrocarpon spp. (now Ilyonectria spp.)
Affects 16 plants
Cylindrocladium Blight and Root Rot
Cylindrocladium scoparium
Affects 135 plants
Cylindrocladium Root Rot
Cylindrocladium spp. (now Calonectria spp.)
Affects 1 plant
Cytospora Canker
Cytospora spp. (Valsa spp., Leucostoma spp.)
Affects 136 plants
Damping-off
Several soilborne
Affects 66 plants
Dead Bud
Abiotic or frost injury
Affects 33 plants
Dead Spur
Apple dead
Affects 12 plants
Decline
Pear decline
Affects 5 plants
Decline/Collapse Syndrome
Candidatus Phytoplasma pyri
Affects 6 plants
Die-off
Pythium spp. and Rhizoctonia solani
Affects 1 plant
Diplodia Canker
Diplodia seriata and D
Affects 12 plants
Diseases
Three viruses generally considered as \"latent\" in apple...
Affects 18 plants
Dothistroma Needle Blight (Red Band)
Dothistroma septosporum (and/or D
Affects 42 plants
Downy Leaf Spot
Pseudomicrostroma juglandis (syn. Microstroma juglandis)
Affects 6 plants
Downy Mildew
Peronospora sparsa
Affects 43 plants
Drippy Dieback
Lonsdalea quercina subsp
Affects 13 plants
Drought Injury
Many conifers
Affects 37 plants
Dry Berry
Described as
Affects 14 plants
Dry Cell (Dry Berry) Syndrome
Monilinia rubi
Affects 14 plants
Dutch Elm Disease
Ophiostoma novo-ulmi
Affects 8 plants
Dwarf Mistletoe
Arceuthobium spp. (parasitic plant)
Affects 64 plants
Early Leaf Spot
Phyllosticta cotoneastri (primary); Entomosporium maculat...
Affects 13 plants
Eastern Filbert Blight
Anisogramma anomala
Affects 6 plants
Elytroderma Needle Cast
Elytroderma deformans
Affects 53 plants
Eola Rasp Leaf (Yellow Bud Mosaic)
Eola rasp
Affects 36 plants
Esca, Young Esca, and Petri Disease
Phaeomoniella chlamydospora, Phaeoacremonium aleophilum, ...
Affects 2 plants
European Canker Nectria Canker
Neonectria ditissima (syn. Neonectria galligena), Nectria...
Affects 2 plants
Eutypa Dieback
Eutypa lata
Affects 2 plants
Fabraea Leaf Spot
Fabraea maculata
Affects 4 plants
Failure to bloom
Abiotic
Affects 5 plants
Fasciation
Multiple possible causes (see Disease Cycle section)
Affects 45 plants
Fig Mosaic Disease
Fig mosaic virus
Affects 2 plants
Fire Blight
Erwinia amylovora
Affects 68 plants
Flat Apple Disease
Apple flat
Affects 12 plants
Flower and Petal Blight
Ciborinia camelliae
Affects 2 plants
Frosty Mildew
Microstroma album
Affects 50 plants
Fruit Rot
Phytophthora cactorum
Affects 29 plants
Fruit Rot and Cane Botrytis
Botrytis cinerea
Affects 14 plants
Fruit Rot, Phytophthora
Phytophthora cactorum
Affects 12 plants
Fruit Russeting
Fruit russet
Affects 17 plants
Fungal Cankers
Although bacterial
Affects 36 plants
Fungal leaf spots
Phyllosticta sp. and Dothiorella candollei (formerly Macr...
Affects 5 plants
Fusarium Canker
Fusarium spp.
Affects 5 plants
Fusarium Root Rot
Fusarium spp.
Affects 3 plants
Fusarium Wilt
Fusarium oxysporum
Affects 6 plants
Fusicoccum Canker (Godronia Canker)
Godronia cassandrae
Affects 12 plants
Ganoderma Root and Butt Rot
Ganoderma applanatum
Affects 50 plants
Grapevine Red Blotch Disease
Grapevine red blotch virus
Affects 2 plants
Grapevine Trunk Disease
Eutypa lata, Botryosphaeria spp., Phaeomoniella chlamydos...
Affects 2 plants
Gray Blight
Pestalotiopsis sydowiana
Affects 132 plants
Gray Mold
Botrytis cinerea
Affects 78 plants
Green Algae
Green algae
Affects 15 plants
Green Crinkle Disease
Affects 12 plants
Grovesiella Canker
Grovesiella punctata
Affects 15 plants
Gumming
Mechanical injury
Affects 36 plants
Gumming (Gummosis)
Non-pathogenic (physiological response to injury/stress)
Affects 33 plants
Gummy Stem Blight (Vine Decline)
Stagonosporopsis cucurbitacearum (syn. Didymella bryoniae)
Affects 1 plant
Hail damage
Abiotic
Affects 5 plants
Herbicide damage
Abiotic
Affects 5 plants
Heterobasidion Root Disease
Heterobasidion annosum
Affects 78 plants
Hypocotyl Rot and Root Rot
In most
Affects 42 plants
Incorrect soil pH
Non-pathogenic (abiotic — soil pH imbalance)
Affects 12 plants
Inonotus Root and Butt Rot
Pseudoinonotus dryadeus
Affects 50 plants
Interior Needle Blight
Multiple fungi (Rhizosphaera spp., Stigmina spp., Lirula ...
Affects 15 plants
Iron Chlorosis
Abiotic (iron deficiency)
Affects 2 plants
June Drop
The normal
Affects 36 plants
Laminated Root Rot
Coniferiporia sulphurascens
Affects 9 plants
Latent Virus Diseases
Three viruses
Affects 12 plants
Leaf And Cane Spot
[VERIFY]
Affects 5 plants
Leaf and Flower Gall
Exobasidium vaccinii
Affects 135 plants
Leaf and Shoot Blight
[VERIFY]
Affects 11 plants
Leaf and Stem Blight
Pseudonectria buxi (asexual: Volutella buxi) and P
Affects 2 plants
Leaf Blight
Fungal agents (multiple)
Affects 46 plants
Leaf Blight (Keithia Blight)
Didymascella thujina
Affects 3 plants
Leaf Blister
Taphrina spp.
Affects 109 plants
Leaf Blotch
Non-pathogenic (physiological)
Affects 11 plants
Leaf Burn
Non-pathogenic (abiotic stress)
Affects 132 plants
Leaf Curl
Taphrina deformans
Affects 36 plants
Leaf Drop
Non-pathogenic (physiological)
Affects 2 plants
Leaf Gall
Abiotic or fungal
Affects 40 plants
Leaf Gall (Blisters)
Abiotic or fungal
Affects 2 plants
Leaf Rust
Uredinales (rust fungi)
Affects 11 plants
Leaf Scorch
abiotic (drought, heat stress) or bacterial (Xylella fast...
Affects 324 plants
Leaf scorch (marginal leaf necrosis)
Sphaerulina azaleae (formerly Septoria azaleae)
Affects 7 plants
Leaf Scorch And Leaf Roll
Sphaerulina azaleae (formerly Septoria azaleae)
Affects 22 plants
Leaf Spot
Symptom category — not a single disease
Affects 545 plants
Leaf spot (Diplocarpon)
Diplocarpon spp.
Affects 6 plants
Leaf Spot and Twig Blight
Diaporthe vaccinii (asexual Phomopsis vaccinii)
Affects 2 plants
Leaf Spots and Blights
Phyllosticta sp. and Dothiorella candollei (formerly Macr...
Affects 2 plants
Leaf Spots and Shothole
Phyllosticta sp. and Dothiorella candollei (formerly Macr...
Affects 1 plant
Leaf Spots and Twig Blights
Diaporthe vaccinii (asexual Phomopsis vaccinii)
Affects 12 plants
Leafroll
Grapevine leafroll virus
Affects 38 plants
Leather Rot
The fungal
Affects 2 plants
Lilac Ring Mottle
Lilac ring mottle virus
Affects 12 plants
Lime-induced Chlorosis
Non-pathogenic (iron deficiency)
Affects 143 plants
Little Cherry
Little cherry virus-1 and Little cherry virus-2
Affects 33 plants
Lophodermella Needle Cast
Lophodermella concolor
Affects 53 plants
Lophodermium Needle Cast
Lophodermium spp.
Affects 53 plants
Lower Stem Canker
[VERIFY]
Affects 4 plants
Madrone Canker
[VERIFY]
Affects 1 plant
Magnesium Deficiency
Abiotic
Affects 20 plants
Marginal leaf necrosis
Xylella fastidiosa
Affects 140 plants
Marssonina leaf and twig spot
Marssonina spp.
Affects 14 plants
Marssonina Leaf Spot
Marssonina spp.
Affects 11 plants
Medusa Needle Blight
Davisomycella medusa
Affects 42 plants
Mistletoe
Arceuthobium spp. (parasitic plant)
Affects 56 plants
Mistletoe (a True Mistletoe)
Phoradendron villosum
Affects 70 plants
Moldy Core and Core Rots
Several different
Affects 12 plants
Mosaic
Apple mosaic virus (ApMV)
Affects 9 plants
Mosses and Lichens
Non-pathogenic
Affects 12 plants
Mottle leaf
Cherry mottle leaf virus
Affects 38 plants
Mummy Berry
Monilinia vaccinii-corymbosi
Affects 13 plants
Necrotic Leaf Blotch (Golden Leaf Drop)
Non-pathogenic (physiological)
Affects 12 plants
Necrotic Leaf Spot
Isolation attempts
Affects 12 plants
Necrotic Ringspot
Rhododendron necrotic ringspot virus
Affects 133 plants
Necrotic rusty mottle
Necrotic rusty mottle virus (uncharacterized)
Affects 38 plants
Necrotic Rusty Mottle (Lambert Mottle) and Rusty Mottle
Uncharacterized graft
Affects 36 plants
Nectria Canker
Neonectria ditissima
Affects 135 plants
Nectria Canker (European Canker)
Neonectria ditissima
Affects 17 plants
Nectria Twig Blight (Coral Spot)
Nectria cinnabarina
Affects 13 plants
Needle Blight
The fungi
Affects 16 plants
Needle Cast
Rhabdocline spp. including R
Affects 63 plants
Needle Cast, Rhabdocline
Rhabdocline spp
Affects 4 plants
Needle Cast, Swiss
Nothophaeocryptopus gaeumannii
Affects 4 plants
Needle Drop
Abiotic or environmental stress
Affects 6 plants
Needle Rusts
Gymnosporangium spp.
Affects 42 plants
Nematode, Dagger
Xiphinema americanum
Affects 8 plants
Nematode, Foliar
Aphelenchoides fragariae
Affects 0 plants
Nematode, Ring
Mesocriconema spp
Affects 2 plants
Nematode, Root-knot
Meloidogyne hapla
Affects 3 plants
Nematode, Root-lesion
Pratylenchus penetrans
Affects 7 plants
Nematode, Stem and Bulb
Ditylenchus dipsaci
Affects 0 plants
Nematode, Stubby-root
Paratrichodorus renifer
Affects 7 plants
Nematode, Stunt
Tylenchorhynchus claytoni
Affects 0 plants
Nematodes
Nematodes are
Affects 7 plants
Neonectia Canker
Neonectria ditissima
Affects 15 plants
Oedema
Non-pathogenic (physiological — water imbalance)
Affects 5 plants
Oil Discoloration of Foliage
abiotic (spray oil residue)
Affects 15 plants
Olive Leaf Spot (Peacock Spot, Peacock's Eye)
Spilocea oleagina (syn. Cycloconium oleaginum)
Affects 1 plant
Orange Rust
Phragmidium spp.
Affects 14 plants
Orford-cedar (Chamaecyparis lawsoniana)
[VERIFY]
Affects 1 plant
Ovulinia Petal Blight
Ovulinia azaleae
Affects 135 plants
Pacific Coast Pear Rust
Gymnosporangium libocedri
Affects 4 plants
Pear Scab
Venturia pirina
Affects 0 plants
Pear Trellis Rust
Gymnosporangium spp.
Affects 23 plants
Pecky Rot
Postia amara
Affects 1 plant
Pencil Rot (Brown Pocket Rot)
Stem decay
Affects 3 plants
Perennial Canker (Bull's-eye Rot)
Cryptosporiopsis perennans
Affects 18 plants
Phomopsis Twig Blight
Diaporthe vaccinii
Affects 20 plants
Phyllosticta Leaf Spot
Phyllosticta spp.
Affects 45 plants
Physiological leaf spot
Non-pathogenic (physiological disorder)
Affects 138 plants
Physiological shothole
Abiotic
Affects 6 plants
Phytophthora Blight
Phytophthora spp.
Affects 133 plants
Phytophthora Blight and Dieback
Many different
Affects 132 plants
Phytophthora Canker
Phytophthora syringae
Affects 16 plants
Phytophthora Canker and Shoot Blight
Phytophthora spp. (P
Affects 12 plants
Phytophthora Dieback
Phytophthora spp.
Affects 24 plants
Phytophthora fruit rot
Phytophthora spp
Affects 13 plants
Phytophthora leaf & twig blight
Phytophthora spp.
Affects 0 plants
Phytophthora Leaf and Twig Blight
Phytophthora ilicis
Affects 10 plants
Phytophthora ramorum (Ramorum Blight / Sudden Oak Death)
Phytophthora ramorum
Affects 0 plants
Phytophthora Root and Crown Rot
Phytophthora cinnamomi
Affects 4 plants
Phytophthora Root and Runner Rot
Phytophthora spp.
Affects 13 plants
Phytophthora Root Rot
Phytophthora spp. (P
Affects 397 plants
Phytophthora Root Rot and Wilt
Phytophthora spp.
Affects 132 plants
Phytophthora Stem Canker
Phytophthora spp.
Affects 1 plant
Pierce's Disease
Xylella fastidiosa
Affects 2 plants
Pine Wilt
Bursaphelenchus xylophilus
Affects 42 plants
Pinot Leaf Curl
Apples chlorotic leaf spot virus (ACLSV)
Affects 2 plants
Pitting
Multiple fungal agents
Affects 36 plants
Plum Pockets
Taphrina pruni
Affects 36 plants
Plum Pox (Sharka)
Plum pox virus (PPV)
Affects 36 plants
Pollination failure
Abiotic/Environmental factors
Affects 1 plant
Port Orford cedar root rot
Phytophthora lateralis
Affects 17 plants
Postharvest Rots
Many fungi
Affects 36 plants
Powdery Mildew
Multiple obligate biotrophic fungi (Erysiphales: Erysipha...
Affects 599 plants
Prune Dwarf
Prune dwarf
Affects 36 plants
Prunus Necrotic Ringspot
Prunus necrotic ringspot virus (PNRSV)
Affects 38 plants
Pseudomonas Blight
Pseudomonas syringae pv. syringae
Affects 14 plants
Pseudomonas Blossom Blast and Dieback
Pseudomonas syringae
Affects 4 plants
Purple Blotch
Thrips tabaci
Affects 15 plants
Purple Needle Eater (Delphinella Shoot Blight)
Delphinella balsameae
Affects 15 plants
Pyrenobotrys Leaf Spot
Pyrenobotrys compacta
Affects 13 plants
Pythium Root Rot
Pythium spp.
Affects 2 plants
Ramorum Shoot Dieback
Phytophthora ramorum
Affects 0 plants
Rasp Leaf
Cherry rasp
Affects 36 plants
Red Leaf Spot
Phyllosticta cotoneastri
Affects 13 plants
Red Leaf Spotting
Several factors
Affects 15 plants
Replant Disease
Pythium spp., Phytophthora spp., Rhizoctonia spp., Fusari...
Affects 62 plants
Rhizosphaera Needle Cast
Nothophaeocryptopus gaeumannii
Affects 16 plants
Ringspot
Tomato ringspot
Affects 19 plants
Ringspot Disease
Camellia ringspot virus
Affects 2 plants
Ripe Rot (Anthracnose)
Colletotrichum spp.
Affects 12 plants
Root and Crown Rot
Phytophthora cinnamomi
Affects 4 plants
Root and Cutting Rots
Phytophthora spp. and Pythium spp.
Affects 26 plants
Root and Stem Rot
Phytophthora syringae
Affects 2 plants
Root Rot
Symptom category — not a single disease
Affects 199 plants
Root Rot (Armillaria ostoyae)
Armillaria ostoyae
Affects 42 plants
Root Rot (Armillaria)
Armillaria spp.
Affects 1 plant
Root Rot (Phytophthora spp.)
Phytophthora spp.
Affects 176 plants
Rose Mosaic
Several viruses
Affects 8 plants
Rosette
This problem
Affects 36 plants
Rubbery Wood and Flat Limb
These diseases
Affects 12 plants
Rugose
[VERIFY] (multiple possible causes)
Affects 36 plants
Russeting
Non-pathogenic (physiological disorder — epidermal cell d...
Affects 36 plants
Rust
Thekopsora minima and Naohidemyces vaccinii
Affects 399 plants
Salt Damage
Excess sodium chloride
Affects 42 plants
Salt injury
Excess sodium chloride
Affects 1 plant
Scab
Venturia inaequalis
Affects 66 plants
Scab (Gummosis)
Pseudomonas syringae
Affects 1 plant
Scar Skin and Dapple Apple
These diseases
Affects 12 plants
Schweinitzii root and butt rot
Phaeolus schweinitzii
Affects 16 plants
Sclerotinia Stem Rot (White Mold)
Sclerotinia sclerotiorum
Affects 1 plant
Scorch
The blueberry
Affects 12 plants
Seiridium Canker
Seiridium cardinale
Affects 37 plants
Septoria Leaf Spot
Septoria spp.
Affects 18 plants
Septoria Leaf Spot and Canker
Septoria spp.
Affects 11 plants
Shock
The blueberry
Affects 12 plants
Shoot Blight
Phytophthora cactorum"heeled in\" (placed in sawdust pile...
Affects 52 plants
Shoot Tip Dieback
Phomopsis spp., Kabatina spp., and Pestalotiopsis spp.
Affects 3 plants
Shothole
Stigmina carpophila or Diaporthe spp.
Affects 36 plants
Shothole (Coryneum Blight)
Stigmina carpophila
Affects 35 plants
Silver Leaf
Chondrostereum purpureum
Affects 59 plants
Sirococcus Shoot Blight
Sirococcus conigenus
Affects 42 plants
Slime Mold
Physarum spp. or similar myxomycetes
Affects 2 plants
Sooty Bark Disease
Cryptostroma corticale
Affects 45 plants
Sooty Mold
Fumago vagans
Affects 23 plants
Sooty Mold (Black Mold)
Saprophytic fungi
Affects 2 plants
Sooty-bark Canker
Cryptostroma corticale
Affects 11 plants
Sour Cherry Yellows
Prune dwarf
Affects 36 plants
Sour Rot
Geotrichum candidum
Affects 2 plants
Sparassis Root Rot
Sparassis crispa (syn. S
Affects 16 plants
Spotted Wilt
Tomato spotted wilt virus (TSWV)
Affects 2 plants
Sprinkler Rot (Phytophthora Fruit Rot)
Phytophthora spp
Affects 40 plants
Spur Blight
Xenodidymella applanata
Affects 15 plants
Stamen Blight
Anthophora dendrobii or Botryotinia fuckeliana
Affects 14 plants
Stem Canker
Botryosphaeria corticis
Affects 50 plants
Stem Decay
Stem decay
Affects 61 plants
Stem Gall
Agrobacterium tumefaciens
Affects 1 plant
Stem Pitting
Several causes
Affects 36 plants
Stem Rot
Phytophthora syringae (primary), P
Affects 18 plants
Stigmina Blight
Pseudocercospora thujina
Affects 4 plants
Stony Pit
Graft-transmissible virus (causal virus not definitively ...
Affects 4 plants
Storage Problems
Botrytis cinerea, Penicillium spp., and others; abiotic d...
Affects 12 plants
Storage Rots
Penicillium spp., Botrytis cinerea
Affects 4 plants
Sunburn
Non-pathogenic (abiotic — solar radiation damage)
Affects 10 plants
Sycamore Anthracnose
Apiognomonia veneta (syn. Gnomonia platani)
Affects 4 plants
Tar Spots
Rhytisma punctatum
Affects 45 plants
Thousand Cankers Disease
Geosmithia morbida (vectored by Pityophthorus juglandis)
Affects 7 plants
Tip Blight
Diaporthe vaccinii or Diplodia tip blight agents
Affects 61 plants
Tissue Proliferation
Non-pathogenic; genetic/physiological abnormality from ti...
Affects 1 plant
Tomato Spotted Wilt
Tomato spotted wilt virus (TSWV)
Affects 5 plants
Trellis Rust (European Pear Rust)
Gymnosporangium sabinae
Affects 4 plants
Twig Blight
Diaporthe vaccinii
Affects 87 plants
Twig Blight (Scab)
Venturia spp. or Fusicladium spp. (specific oak pathogen ...
Affects 11 plants
Twig blight (Venturia)
Venturia spp.
Affects 14 plants
Twig Canker
Sporocadus lichenicola
Affects 12 plants
Twig Dieback
Phacidiopycnis washingtonensis
Affects 2 plants
Twig Dieback and Canker
Phacidiopycnis washingtonensis
Affects 12 plants
Union Necrosis and Decline
Tomato ringspot
Affects 12 plants
Upper and Lower Stem Canker (Phoma Blight)
Phoma spp.
Affects 4 plants
Upright Dieback
Diaporthe vaccinii (asexual: Phomopsis vaccinii)
Affects 13 plants
Variegation
Both a
Affects 2 plants
Vascular Streak Dieback
Ceratobasidium theobromae (syn. Oncobasidium theobromae)
Affects 7 plants
Vein Yellows (Red Mottle and Sooty Ringspot of Quince)
Vein yellows
Affects 4 plants
Verticillium Wilt
Verticillium dahliae
Affects 181 plants
Virus
Raspberry bushy dwarf virus and related viruses
Affects 99 plants
Virus and Virus-like Diseases
Multiple plant viruses
Affects 4 plants
Virus Diseases
Blueberry mosaic virus and related viruses
Affects 94 plants
Virus-induced Cherry Decline
Cherry leafroll virus (CLRV); complex with prune dwarf vi...
Affects 36 plants
Volutella Leaf and Stem Blight (Canker)
Pseudonectria buxi
Affects 4 plants
Walnut Blight
Xanthomonas arboricola pv. juglandis
Affects 5 plants
Web Blight
Rhizoctonia spp. (binucleate)
Affects 5 plants
Western Gall Rust
Endocronartium harknessii
Affects 53 plants
White mold
Sclerotinia sclerotiorum
Affects 2 plants
White Mold Sclerotinia Rot
Sclerotinia sclerotiorum
Affects 3 plants
White Pine Blister Rust
Cronartium ribicola
Affects 53 plants
White Pocket Rot (Piped Rot)
Inonotus dryophilus
Affects 50 plants
Winter Injury
Cold and
Affects 9 plants
Witches' Broom
Taphrina wiesneri
Affects 195 plants
Witches' Broom Rust
Gymnosporangium juniperi-virginianae or similar
Affects 13 plants
Witches'-broom (Cherry leaf curl)
Taphrina wiesneri
Affects 38 plants
Wood Decay
Limb and
Affects 125 plants
X-Disease
Candidatus Phytoplasma pruni
Affects 37 plants
Yellow Root Rot
Perreniporia subacida
Affects 3 plants
Yellow Rust
Phragmidium rubi
Affects 14 plants
Yellow-green Mottle Syndrome
Affects 4 plants
Young Vine Decline
Phaeomoniella chlamydospora, Phaeoacremonium spp. (P
Affects 2 plants