Symptoms of pea cyst nematode on field beans and peas

Pea cyst nematodes affect pea and bean roots causing stunting and premature death.

Scientific name: Heterodera goettingiana

The pea cyst nematode attacks the roots of pea and beans, though the latter rarely shows symptoms. The pest is not ubiquitous and incidence varies from year to year.

Any symptoms appear in early summer before flowering, with areas of the crop becoming pale and stunted. Plants turn yellow and have an upright appearance, small leaves and may flower prematurely.

Pods often fail to develop and plants may die prematurely. Root systems are often poorly developed and contain tiny, white, lemon-shaped cysts containing nematode eggs. These later turn brown and can remain viable for up to 20 years.

Crops in areas with a long history of frequent pea cultivation and those on lighter, sandier soils tend to be at greatest risk. Yield losses can be sustained with soil populations of five eggs per gram of soil.