Effect of different abiotic environmental factors and host age on development of fenugreek powdery mildew (Erysiphe polygoni)

Abstract

Powdery mildew of fenugreek is an important and serious disease especially during flowering and
pod formation stage of the crop. The study was conducted to determine the factors affecting infection
of fenugreek by Erysiphe polygoni under controlled conditions. Maximum per cent disease intensity
by Erysiphe polygoni was recorded at 24°C, there was significant increase in per cent disease intensity
with increase in temperature from 15°C to 24°C and further decreased at 27°C temperature. 90 per
cent relative humidity closely followed by 80 per cent relative humidity and 10.14 hours of darkness
and light recorded maximum per cent disease intensity. All the levels of darkness and light were
found significant in influencing disease intensity. It was observed that with the increase in light
hours, the per cent disease intensity increased. It was concluded that darkness condition is stimulatory
decrease disease intensity. When plant inoculated at flowering stage (45 days old) recorded maximum
per cent disease intensity.