​Management of Early Leaf Spot (Cercospora arachidicola) of Groundnut in Rajasthan

Abstract

Background: Early leaf spot caused by Cercospora arachidicola Hori. is most destructive disease in all the groundnut growing areas of Rajasthan, under severe infestation it cause 30-50% losses in pod yield. Recently, Central Insecticide Board (CIB), Faridabade banned 27 pesticides including some important fungicides which are extensively used in plant disease management. Therefore, in the present investigation, our main emphasis was to find out some new fungicides for management of early leaf spot disease. Methods: Ten fungicides (hexaconazole 5% EC, difenconazole 25% EC, propiconazole 25% EC, tebuconazole 25.9% EC, trifloxystrobin 25% + tebuconazole 50% WG, mancozeb 50% WP, chlorothalonil 75% WP, carbendazim 50% WP, carbendazim 12% + mancozeb 63% WP and captan 70% + hexaconazole 5% WP) were evaluated against early leaf spot pathogen (C. arachidicola) both in lab as well as in field condition. The experiment was conducted at ARS, SKRAU, Bikaner during Kharif-2019 on most popular cv. HNG-69 in RBD design with the application of foliar spray of ten different fungicides at different concentrations against early leaf spot disease and compared with an untreated control. Result: Among all the fungicides used in the present investigation, Tebuconazole 25.9% EC was found most effective in inhibiting the mycelial growth of the pathogen followed by trifloxystrobin 25% + tebuconazole 50% WG. Under field condition, it gave maximum (70.73%) disease control with highest pod yield (31.5 q/ha) and net return (Rs 57,500/ha) when applied as foliar spray at 0.1% concentration followed by trifloxystrobin 25% + tebuconazole 50% WG at 0.2%. These treatments can provide an effective and economical management of early leaf spot disease for groundnut cultivators.