Reaction of greengram (Vigna radiata) to Cercospora canescens (ell.) and mart

Cercospora canescens was inoculated onto different aged (20–70 days old) plants of greengram (Cv. Shalimar Mung-1). The genotype was found invariably susceptible at all its growth stages with incubation period of 6–7 days and leaf spot diameter of 7.1–7.4mm as recorded after 15 days of inoculation. Total sugar content showed an increasing trend and ranged from 124 to 129 and 133 to 135mg/g dry weight during pre-and post-flowering periods, respectively. The total phenol content also increased with plant age and was maximum (26.5 mg/g dry weigh) in 60 days old plants following which an insignificant decrease (26.5 mg/g dry weight) was recorded. Twenty five genotypes of greengram were screened for resistance against the pathogen under field conditions. The genotypes showed an indifferent response to invasion by C. canescens and none showed absolute resistance. However, five genotypes viz., ML-935, PDM-54, Pusa Vishal, SM-710 and SM-366 were moderately susceptible and manifested lower leaf spot intensity (27.5–30.4%) and pod infection(34–35.4%).