Ascochyta blight of chickling vetch

Ascochyta blight of chickling vetch is a fungal disease caused by the pathogen Ascochyta lathyri. This fungus belongs to the order Sphaeropsidales and is a specialized parasite affecting leguminous plants. It represents a significant threat to the cultivation of Lathyrus sativus, as it compromises the physiological health of the crop and reduces harvest yields.

The fungus primarily attacks the aerial parts of the plant, including stems, leaves, petioles, and pods. The damage caused by the pathogen manifests as tissue necrosis, which severely inhibits the plant's photosynthetic capacity. In severe cases, the entire plant may wither, and the pods become infected, leading to reduced seed quality and lower germination rates in subsequent seasons.

Symptoms of the infection typically appear as irregular or circular spots on the leaf surface, often featuring a dark, well-defined border. Over time, these lesions develop into gray or brown centers where the fungus produces its reproductive structures, known as pycnidia, which appear as minute black specks. These structures are crucial for the diagnostic identification of the disease in the field.

The development of Ascochyta lathyri is heavily dependent on environmental conditions, particularly high humidity and moderate temperatures. The fungus survives unfavorable seasons within infected crop residues and on or inside contaminated seeds. Spread during the growing season is primarily facilitated by rain splash and wind, which transport the pycnospores to healthy plant tissues, initiating new infection cycles.

• Selection of certified disease-free seeds.
• Chemical treatment of seeds with effective fungicides.
• Strategic crop rotation to reduce inoculum pressure in the soil.
• Removal and destruction of infected crop debris post-harvest.
• Application of foliar fungicides during periods of prolonged wet weather to protect crops.