Morphological characterization and effect of meteorological factors on development of okra powdery mildew

Okra powdery mildew samples collected from Solan and Sirmour districts of Himachal Pradesh revealed the presence of anamorphs only. On the basis of anamorphic characters like ectophytic mycelium, unbranched conidiophores with cylindrical foot cell, oval to roundish or barrel shaped conidia, size, absence of fibrosin bodies in conidium, simple and straight germ tube and presence of appressoria, the associated pathogen was identified as Erysiphe cichoracearum DC. as the causal agent of the disease in Solan and Sirmaur districts of Himachal Pradesh. Maximum conidial germination and germ tube length was recorded at 25°C temperature and 70.4 per cent relative humidity. Moderate air temperature of 25 ± 1°C coupled with slightly less relative humidity (<70%) and less cumulative rainfall helped significantly in disease development.