Study of slow mildewing components of powdery mildew of pea caused by Erysiphe pisi

Progression of powdery mildew (Erysiphe pisi DC ex. Saint Amans) was studied in 4 pea (Pisum sativum L.) genotypes (DPP-54, VRP-12, IC-219028 (A), EC-292166) along with Lincoln as check for components of slow mildewing viz., incubation period, latent period, size of mildew colonies, disease severity, AuDpC and infection rate (r). Maximum incubation and latent period of 5 & 6 days, respectively, was recorded in IC-219028 (A) & DPP-54 and minimum of 3 & 4 days in Lincoln. Upto 9 days countable number of conidia bearing conidiophores were produced on all the lines however there were countless, after 11 days, being maximum in Lincoln. Maximum colony size i.e. 30 mm was observed in Lincoln followed by 24, 23, 18 and 16 mm in VRP-12, EC-2922166, DPP-54 and IC-219028 (A), respectively. Disease severity among all the lines ranged between 70 to 90 per cent. AUDPC values ranged from 2175 to 2737 and maximum value i.e. 2737 was found in Lincoln. Infection rate (r) values ranged between 0.038 to 0.073/day. It was concluded that pea genotypes viz., IC-219028 (A), DPP-54, EC-292166 and VRP-12 were slow mildewers as compared to Lincoln.