Plant Disease Management Handbook

Cause The pea enation mosaic virus. At least 8 species of aphid can transmit the virus but the principal vector is the pea aphid, Acyrthosiphon pisum. After the aphid acquires the virus, it is 8 or more hours before it can transmit it to a pea plant, but the aphid retains the ability to transmit the virus for at least 24 hours, during which time it can fly or be blown long distances.

Cause The cyst nematode, Heterodera goettingiana, is an aggressive parasite that can be quite damaging to a pea crop. Cysts are the dead bodies of females and may contain up to 300 eggs. Cysts are very persistent in the soil, surviving more than 12 years, and can be spread by moving contaminated soil. Pea and fava bean are the main economic hosts. Certain vetches also can be hosts. Root invasion is promoted by cool soil temperatures (about 55°F).

Cause A fungus-like microorganism, Peronospora viciae (formerly P. pisi), which overwinters on diseased plant refuse in soil. The pathogen has never been shown to be transmitted by seed internally or externally.

See:

Pea (Pisum sativum) - Seed Rot and Damping-off

See:

Pea (Pisum sativum) - Ascochyta Blight (Basal Stem Rot or Black Stem)

Cause A bacterium, Pseudomonas syringae pv. pisi, that is internally seedborne and can survive in pea straw from one season to the next. This disease can be a problem in extremely wet springs where sprinkler irrigation is used and if seed for this year's crop came from a blight-infested field.

Cause Stem, crown, and foliar diseases of pea are caused by a complex of Phoma medicaginis var. pinodella, Ascochyta pisi, and Mycosphaerella pinodes. Crown rot is caused primarily by P. medicaginis var. pinodella. Upper stem, foliar, and pod blights are caused by A.

Cause A fungus-like microorganism, Aphanomyces euteiches f. sp. pisi, that overwinters as thick-walled oospores, which can be spread by water, wind, infected plant debris, soil movement, or by tillage equipment. Oospores are produced within infected root tissue, which decomposes, releasing the oospores into surrounding soil. The fungus can infect and multiply in other legume roots, such as clover, alfalfa, lentil, Cava bean, and common bean.

Cause The fungus, Itersonilia perplexans, is a common saprophyte on umbelliferous crops as well as some weeds and other cultivated plants including brassicas. It overwinters as chlamydospores in soil or plant debris, on living parsnip roots, and can also infest seed. It spreads by wind as ballistospores, which die rapidly once in contact with soil microorganisms. Disease is favored by moist and cool conditions; 68°F is optimum for growth of the fungus.

See:

Greenhouse Plants, Ornamental - Black Root Rot