Development of Didymella rabiei on chickpea plant residues

Abstract

Ascochyta blight caused by Ascochyta rabiei (Pass.) Labrousse is the economically most important disease on chick pea in many countries where the crop is grown. Under moist conditions the fungus Asc. Rabiei grows fast from the spots, covering the entire stems and pods with pycnidia and consecutively with perithecia as well. Main factors for the development and maturing of the perithecia are the high humidity and temperatures of 5 – 10 °С.The relative frequency of the formed perithecia was significantly lower than the frequency of pycnidia. The morphological characteristics of the perithecia, asci and ascospores confrmed the nature of Didymella rabiei. The investigation for sexual compatibility showed that D. rabiei was a heterothallic fungus. Based on иossing, the four isolates involved in the study were divided into two groups or mating types. Under fсeld conditions in North-East Bulgaria, mature ascospores were observed at the beginning of March and the discharge of the majority of them continued for about two months.