GENETIC AND BIO-CHEMICAL STRETIGIES FOR THE MANAGEMENT OF POWDERY MILDEW DISEASE OF WATERMELON (CITRULLUS LANATUS)

Abstract

Watermelon is a highly nutritious crop and its yield is affected by powdery mildew worldwide. Powdery mildew incidence has increased in recent years due to the tunnel farming trend. Conventional strategies like cultural practices e.g. sowing time and over fertigation have not been effective to control the powdery mildew. So, present study was carried out to evaluate different watermelon cultivars against powdery mildew and to provide information about the effectiveness of different fungicides and plant extracts for its control. The experiments were carried out in research area of Department of Plant Pathology, University of Agriculture Faisalabad during 2013-2014. Twelve varieties of watermelon were sown in randomized complete block design with three replications. Inoculation was done by spray method. After the onset of disease, fungicides and plant extract treatments were applied weekly. Data were analyzed statistically and treatment means were compared by using Least Significant Difference (LSD) test. Significant differences for powdery mildew resistance were observed in 12 genotypes and varieties WT2257 and Zcugma F1 showed only 3% disease incidence showing higher disease resistance. Other resistant watermelon verieties were Panther, Pata Nagra and Ayesha 1 with disease incidence of 5, 7 and 9% respectively. On the other hand Sugar Baby and Anar Kali varieties showed 78 and 67% disease. Among the six extracts, neem extract showed least disease incidence of 17.56%. Garlic and sohanjana extracts showed 25.78 and 30.44% disease occurrence. Among the six fungicides, the least disease incidence was recorded in Gemstar with mean of 9.78%. Raydar and Crest fungicide sprayed crop had 15 and 19% disease. Highest disease incidence was recorded in control with mean of 69.11%. It is concluded that genetic resistance, pesticide and plant extract application showed significant variation in disease incidence.