Integrating Cultivar Resistance and Seed Treatment with Planting Dates to Manage Chickpea Ascochyta Blight

Abstract

The influence of chickpea (Cicer arietinum) planting date on seasonal epidemics of Ascochyta blight caused by Ascochyta rabiei (Pass.) Labrousse and on grain yield was evaluated during the 1997 and 1998 cropping seasons. Two chickpea cultivar (Ghab 1 and Ghab 3) and 2 breeding lines (FLIP 90-96 and F 88-85) were used in the field trials at 3 different locations representing the different agro ecological zones in which winter chickpea is grown in Syria and in most of the Mediterranean countries. Four field plantings were made at 14-day intervals from mid November to mid March. All plots were initially inoculated with infected debris and disease development followed natural prevailing environmental conditions. Ascochyta blight disease severity ratings were taken at early flowering and again at podding and grain yield for each plot was measured at harvest. There was a significant (p<0.05) increase in disease severity between the first and third planting in all the entries at all the locations and for both years. The difference in disease severity resulted in significant yield differences but not in differences in seed quality. Under Syrian and Mediterranean conditions, an increase in Ascochyta blight severity can be expected with early planting of chickpea before January and this can result in a corresponding big loss in crop yield. The loss in yield from disease through early plantings however, is more than compensated for, by the reduction in yield due to other environmental parameters in late spring planting, if moderate resistant cultivars are planted.