Category : Fungal
Aphanomyces root rot (Common root rot)
Aphanomyces euteiches
Symptoms
Leaves turning yellow starting from bottom of plant and moving upwards; pod production reduced; soft dark lesions on roots; plants may be severely stunted
Cause
Fungus
Comments
Management
No fungicides effectively control this disease and no pea varieties with high resistance, control therefore relies on avoiding planting in infested fields; rotate crops to avoid build up of disease in soil
Ascochyta disease
Mycosphaerella pinodes
Phoma medicaginis
Ascochyta pisi
Ascochyta lesions on pods and leaves
Symptoms
Tan or purple lesions on leaves, stems and pods which may expand and produce a concentric ring pattern; blossoms or pods may drop or become distorted if lesions girdle sepals
Cause
Fungi
Comments
Management
Grow peas in dry areas; use an appropriate fungicide to treat seeds prior to planting; discard any seed which is known to be heavily infected
Brown spot
Psuedomonas syringae
Symptoms
Water-soaked spots on leaves, stems and pods identical to those caused by bacterial blight; after several days lesions turn tan, lose their water-soaked appearance and resemble a scorch or burn; stem lesions are sunken and elongated and spread upwards; symptomatic leaves dry and drop from plant
Cause
Bacterium
Comments
Management
Plant only disease-free seed; continuously rotate crops; avoid planting peas in fall when they are more likely to be injured by inclement weather
Downy mildew
Peronospora viciae
Symptoms
Yellow-brown blotches on upper surface of leaves; angular patches of fluffy white-gray fungus on lower side of leaves; plant growth may be stunted or distorted and whole plant may die before flowering; plant may produce
Cause
Fungus
Comments
Management
Rotate crops for at least 5 years; till crop debris deeply; avoid sowing pea in late Autumn at greater soil depths as this can promote severe infections
Fusarium root rot
Fusarium solani
Symptoms
Stunted plant growth; yellowing, necrotic basal leaves; brown-red or black streaks on roots that coalesce as they mature; lesions may spread above the soil line
Cause
Fungus
Comments
Management
There are currently no pea varieties with resistance to Fusarium root rot so control relies on cultural practices e.g. do not plant peas in same area more than once in any 5 year span or treating seeds with an appropriate fungicide prior to planting
Gray mold (Botrytis mold)
Botrytis cinerea
Symptoms
Fuzzy gray elongated lesions whoch girdle stem causing wilting of upper parts of plant; lower leaves may be covered in fuzzy gray growth which causes them to dry out and shrivel; small, oval, water-soaked lesions on pods which are tan in color; pod lesions spread irregularly and become gray and sunken; young pods may shrivel and become covered in fuzzy, gray mycelial growth
Cause
Fungus
Comments
Management
There is no reported resistance to gray mold in pea; potassium deficiency may make plants more susceptible and should be supplemented in deficient soils; the fungus causing gray mold has developed resistance to many systemic fungicides and control relies on the application of an appropriate protective fungicides if flowering and pod set coincides with wet weather
Powdery mildew
Erysiphe pisi
Powdery mildew on pea
Powdery mildew on pea
Symptoms
Yellow spots on upper surface of leaves; powdery gray-white areas which coalesce to cover entire plant; if plant is heavily infected it may appear light blue or gray in color
Cause
Fungus
Comments
Management
Plant resistant varieties, particularly if sowing late; use overhead irrigation (washes fungus from leaves and reduces viability); plant crop as early as possible; frequent applications of sulfur may be required to control heavy infestations
Rhizoctonia seedling blight
Rhizoctonia solani
Symptoms
Water-soaked sunken, red-brown lesions on hypocotyls (germinating shoot below seed leaves) and epicotyls (shoot above seed leaves); death of growing tip as it emerges from soil; new shoots may emerge from a node at seed but may also be killed
Cause
Fungus
Comments
Management
Crop rotation helps to reduce the build up of the fungus in the soil; reduce soil compaction; do not plant seeds too deep
Septoria blotch
Septoria pisi
Septoria blotch symptoms on pea
Septoria lesions on pea pods
Septoria blotch symptoms on pea
Septoria lesions on pea foliage
Septoria blotch symptoms on pea
Symptoms
Irregular yellow lesions on leaves and pods with no definitive margin that coalesce to form large yellow patches; large patches may dry out and become covered in black fungal fruiting bodies
Cause
Fungus
Comments
Management
Rotating crops regularly prevents disease build-up in soil
Category : Bacterial
Bacterial blight
Pseudomonas syrngae
Symptoms
Small, water-soaked spots on leaves steam and pods which coalesce and turn brown and necrotic; lesions on leaves are angular and develop translucent centers; lesions on stem may enlarge and girdle stem, killing plant parts above; lesions on pods may cause seeds to be covered in slime
Cause
Bacterium
Comments
Management
Plant resistant varieties; plant only disease-free seed; disinfect all tools and equipment regularly; avoid sprinkler irrigation
Streak
Pea streak virus (PSV)
Symptoms
Purple or brown necrotic streaks on stems and petioles; small brown necrotic lesions on leaves; brown, sunken lesions on pods; pods fail to fill properly or do not fill at all; pods discolored; dieback of growing tips; chlorosis of leaves
Cause
Virus
Comments
Management
No resistance to virus; avoid planting peas close to established alfalfa; insecticide application of little benefit due to short time aphid requires to transmit virus but can help control secondary spread
Category : Viral
Enation mosaic
Pea enation mosaic virus (PEMV)
Symptoms
Blister-like outgrowths (enations) on underside of leaves and on pods; leaves with translucent areas; severely deformed plants
Cause
Virus
Comments
Management
In areas where virus is a problem, early planting may allow plants to mature before virus becomes severley damaging; control of aphid populations and hosts plants which act as reservoirs can help control spread of virus
Mosaic
Red clover vein mosaic virus (RCVMV)
Symptoms
Mottled patterns on leaves; yellow leaf veins; distorted leaves; stunted plants which often die
Cause
Virus
Comments
Management
No known resistance to virus, control depends on control of aphid populations; apply appropriate insecticide if aphid populations are significant