Sclerotinia - Peas
Sclerotinia sclerotiorum
Pathogen
Fungus
Hosts
Peas, oilseed rape, potatoes, carrots, lettuce, beans and other vegetable crops.
Symptoms
A white fungal growth develops from leaf or stem spots and hard, black resting bodies (sclerotia) form in the stem cavity. Infected stems have a conspicuous 'bleached' appearance.
Development
Soil-borne sclerotia germinate to form apothecia (small trumpet-like structures) which release air-borne ascospores. In the presence of surface moisture these spores germinate on senescing flowers which have dropped and attached to the lower leaves. The spores can also directly infect via plant wounds or damage caused by pests or by machinery. After establishing the mycelium moves into the leaves and stem of the host plant. Sclerotia subsequently develop in the infected stem cavities are are realeased into the soil when the weakened stems collapse.
Favourable Factors
Warm, wet conditions and proximity to other susceptible brassica or legume crops.
Importance
Stems collapse, yield losses and possible rejection by processors.
Control
There are no resistant varieties
Adopt a rotation of at least 4 years between bean, pea and oilseed crops.
Remove or bury infected stubble as deeply as possible
Effective removal of host weeds might reduce disease incidence
Apply foliar fungicides during flowering
