Ascochyta blight of chickpea

Ascochyta rabiei is a fungal pathogen within the Fungi kingdom, responsible for causing Ascochyta blight in chickpeas. It is considered one of the most economically significant diseases in chickpea production worldwide, capable of causing devastating yield losses under favorable environmental conditions.

The fungus attacks all above-ground parts of the plant, including leaves, stems, pods, and seeds. Initial symptoms appear as spots with dark margins and necrotic centers containing pycnidia. As the disease progresses, stems may snap, leading to plant death and reduced grain quality, with the seeds becoming vectors for the fungus.

The life cycle of Ascochyta rabiei is heavily reliant on infested crop debris and infected seeds. During the growing season, pycnidiospores are dispersed primarily by rain splash and wind. The pathogen can survive for several years in soil, provided that the climate remains temperate or that infected plant material persists.

Epidemics are most severe in cool and wet weather conditions, with temperatures ranging between 15°C and 25°C. High relative humidity and frequent rainfall are the primary drivers for disease spread, as these conditions are essential for the production and germination of fungal spores.

Effective management requires an integrated approach to mitigate the risks. Primary strategies include using resistant or tolerant cultivars, ensuring a crop rotation cycle that excludes chickpea for at least three years, and utilizing high-quality, fungicide-treated seeds. During the growing season, timely application of foliar fungicides is essential to suppress the pathogen.