Epidemiology of Powdery Mildew of Apple caused by Podosphaera leucotricha (Ell.and Ev.) Salm. in Kashmir, India

Abstract

Apple is an economically important horticultural crop that is affected by a number of diseases, including powdery mildew. The disease spread is affected by the environmental conditions during the growth period. The germination and appressoria formation of conidia of powdery of apple initiated after 2 and 4 h, respectively at 20 ±2oC in moist saturated atmosphere. Sporulation started 96 h after incubation on susceptible apple leaves. Cardinal temperatures for powdery mildew development were 10, 20 and 30 oC. Relative humidity levels of 32 percent and above favoured development of powdery mildew. Temperature had negative significant correlation, whereas relative humidity had positive non-significant correlation with incidence of disease.