Pea blight

Pea blight is a serious fungal disease caused by the pathogen Didymella pinodes (anamorph Ascochyta pinodes). It is considered a major limiting factor in pea production worldwide, capable of devastating crops during periods of high humidity and moderate temperatures.

This pathogen primarily infects field peas, but it also affects other legumes such as lentils and beans. The fungus survives primarily in infected crop residues and contaminated seeds, making it a persistent issue in regions with intensive agricultural practices.

Typical symptoms include small, irregular, dark brown spots on the foliage and stems. As the disease progresses, these lesions expand and often merge, leading to necrotic zones, leaf drop, and weakened stems that are highly susceptible to lodging before harvest time.

The development of Didymella pinodes is heavily dependent on moisture. Spores are spread by rain splash and wind, allowing the fungus to move rapidly through a field under humid conditions. The pathogen thrives in dense canopies where humidity remains trapped around the stems.

The economic impact of pea blight is significant, resulting in reduced biomass, fewer pods per plant, and poor grain filling. Moreover, the pathogen severely compromises seed quality, leading to reduced germination rates and the introduction of primary inoculum into new fields.

• Sow only certified disease-free seeds treated with fungicides.
• Maintain a crop rotation of at least 3–4 years away from host legumes.
• Incorporate crop debris into the soil through deep tillage to accelerate decomposition.
• Apply foliar fungicides during critical growth stages if weather conditions are favorable for disease.
• Remove volunteer plants that may serve as a bridge for the pathogen.