Studies on Cercospora leaf spots disease of groundnut under Bundelkhand region

Abstract

Tikka disease of groundnut caused by Cercospora spp. has economic importance to reduced crop yield. Twenty two isolate of Cercospora spp. were recovered from diseased leaves and clustered using UPGMA on the basis of disease reaction on four cultivars (TG-37A, Kadiri-6, Kaushal and Junku). It was observed that three isolates namely C10, C11 and C12 were highly virulent on almost all the groundnut cultivars. Junku variety allowed highest low virulent isolates per cent 77.27 and this variety showed moderate resistance reaction to comparatively less susceptible to Jhansi population of Cercospora spp. The in vitro and in vivo antifungal effects of the eleven fungicides were investigated. Under in vitro, all the fungicides showed most toxic reaction with 50% effective concentrations (EC50) of < 1 ppm. However, they varied in EC90 values. Twenty ppm concentrations of Amistar Top (Strobilurin+Azole) showed 90% effective concentration (EC90). Amistar (Strobilurin) also showed approximately same results as Amistar Top while EC90 value of Natio, Score, Tilt, Lusture, Folicur, Contaf and Kavach was 50 ppm. It was also observed Strobilurin+Azole group fungicides also dominant in the field condition to control the disease.