Compatibility of pesticides withTrichodermaspp. and their antagonistic potential against some pathogenic soil borne pathogens

Abstract

Two isolates of Trichoderma spp. were tested in vitro for its compatibility with different concentrations of commonly used pesticide and on the antagonistic activity against four pathogenic soils borne pathogens (Fusarium oxysporum f. sp. lycopersici, Sclerotium oryzae, Rhizoctonia solani and Pythium ultimum). Dual culture of pathogens and Trichoderma spp. revealed that IBT-II reduced the growth of Fusarium oxysporum f. sp. lycopersici by 30.05%, Sclerotium oryzae by 58.33%, Rhizoctonia solani by 47.92% and Pythium ultimum by 59.17%. The pesticides tested at different concentrations of 0.1, 0.2 and 0.3% showed that a progressive increase in percent inhibition of radial growth in the bioagents was observed as the concentrations of pesticide increased. Fungicide was found to be more toxic than biopesticide. Biopesticide is found to be compatible at lower concentration i.e. at 0.1% as it showed percent inhibition of only 33.36, 38.00 and 38.22% at 24, 48 and 72hrs period of incubation respectively. Fungicide was found to be incompatible with bioagents as it exhibited toxicity even at lower concentration. It showed maximum inhibition (100%) against isolate MT-4 at 0.1, 0.2 and 0.3% concentration at 24 and 48hrs period of incubation while other isolate IBT-II, showed 87.44 percent inhibition at 0.3% at 72hrs period of incubation. Biopesticide was found to be less toxic than fungicide which indicates the compatibility with bioagents tested. The present result will help delineate the possibility of combining biocontrol agents and agrochemical for use in integrated pest management approach.