ETIOLOGY AND MANAGEMENT OF WILT OF MUSKMELON CAUSED BY Fusarium oxysporum f. sp. melonis (SNYDER AND HANSEN)
Loading...
Date
2018-07
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
University of Horticultural Sciences, Bagalkot (COLLEGE OF HORTICULTURE, GKVK POST, BENGALURU)
Abstract
Fusarium wilt (Fusarium oxysporum f. sp. melonis ) of muskmelon is one of the most destructive and widely distributed disease. The wilt affected plant specimens were collected from different locations viz., Mysuru, Bengaluru and Chitradurga (Hiriyur). Among ten different solid media tested for the growth and sporulation of the fungus, the fungus produced maximum radial growth on potato dextrose agar, malt extract agar and oat meal agar (90.00 mm). The Mysore-I and Mysore isolates-II produced maximum growth and sporulation on potato dextrose agar. Colony growth was creamy white to purplish white colored colony. The Bengaluru and Chitradurga (Hiriyur) isolates showed maximum growth and sporulation on oat meal agar and color of mycelium was yellowish white and whitish purple. The growth and sporulation of the pathogen was maximum at 25ºC. Optimum temperature for growth of pathogen was 20-25ºC. The continuous dark condition was found to be the best condition for growth and sporulation of the pathogen. The pH required for maximum growth was found to be 5.0 to 6.0. The carbon sources on growth of the pathogen was maximum in basal media of Richard’s and Czapek’s medium amended with starch and sucrose. Among the different nitrogen sources tested in Richard’s medium, potassium nitrate was better for the growth of the pathogen. In-vitro studies revealed that Trichoderma viride showed strong antagonistic activity against the pathogen. Among the eight fungicides evaluated under in-vitro condition, carboxin + thiram, benomyl and carbendazim + mancozeb showed total inhibiton of the fungal growth at the concentration of 500, 750 and 1000 ppm. Under in-vivo condition the seed treatment with Trichoderma viride @10g/ kg of seeds + drenching with Trichoderma viride @ 10g/l at 15, 30 and 60 days after planting effectively controlled the disease at 60 and 80 days after sowing. At 90 days after sowing the seed treatment + drenching with carbendazim + mancozeb at 15, 30 and 60 days after planting recorded the lowest disease incidence (41.66 per cent).