Ascochyta blight (chickpeas) (Ascochyta rabiei)

Ascochyta blight (chickpeas): biology

Seed-borne and stubble-borne. Healthy looking seed may carry high levels of ascochyta blight and introduce the disease at multiple points in a field. Air-borne spores produced on stubble may be carried several miles. Within fields the disease spreads by rain-splash.

Visible at all stages of crop development in susceptible varieties. Lesions develop on leaflets, stems and pods which are initially grey, but turn brown with prominent black speckles in the centre. Lesions may girdle the stems causing shoot dieback or death of the whole plant. Pod lesions result in seed shrinkage and discoloration and symptomless seed infection.

With frequent rain showers entire fields of susceptible varieties may be destroyed. Yield losses are negligible in resistant varieties. In resistant varieties limited symptoms may develop late in the season.