Comparative efficacy of rhizosphere mycoflora, fungicides, insecticides and herbicides against groundnut stem rot caused by Sclerotium rolfsii.

摘要

A study was conducted to determine the efficacy of rhizosphere fungal antagonists (Aspergillus niger, A. flavus, Penicillium sp., Rhizopus sp., Fusarium sp., Curvularia sp., Drechslera sp., Alternaria sp. and Trichoderma viride), fungicides (hexaconazole at 1000, 1500 and 2000 ppm, propiconazole at 500, 750 and 1000 ppm, and mancozeb at 2000, 2500 and 3000 ppm), insecticides (chlorpyrifos and quinalphos, each at 1000, 1500 and 2000 ppm) and herbicides (pendimethalin at 500, 750 and 1000 ppm, fluchloralin at 1000, 1250 and 1500 ppm, butachlor at 2000, 2500 and 3000 ppm, and alachlor at 1500, 1750 and 2000 ppm) for the management of groundnut stem rot disease, caused by S. rolfsii [Corticium rolfsii]. T. viride was found significantly superior over other antagonists in inhibiting the growth of S. rolfsii. Among the five pesticides tested for their efficacy, hexaconazole (1000, 1500 and 2000 ppm) and propiconazole (500, 750 and 1000 ppm) completely inhibited the growth of S. rolfsii. Chlorpyriphos completely inhibited the pathogen at one step lower (1500 ppm) and at recommended concentration (2000 ppm), while quinalphos inhibited the growth at 2000 ppm. Of the four herbicides, pendimethalin completely inhibited the growth of S. rolfsii at recommended concentration (1000 ppm). Sensitivity of T. viride against three agrochemicals showed complete inhibition of the growth of T. viride with hexaconazole and 48% with pendimethalin. However, no inhibition of the fungal antagonist was observed with calcium ammonium nitrate.