Compatibility of chemical pesticides and aggravation of <i>Trichoderma</i> spp against Pathogens

Abstract

Compatibility of fungicides viz. Mancozeb and Captan were studied with Trichoderma spp ( T. viride, T. harzianum, T. koningii, T. pseudokoningii and T. virens ) in vitro at different concentrations. It was indicated that lower concentrations of Mancozeb and Captan did not affect the radial growth of Trichoderma spp. However, concentration of Mancozeb above 5000 μg/ml and of Captan above 500 μg/ml were significantly reduced the radial growth of Trichoderma species. Trichoderma viride, T. harzianum, T. virens and T. koningii showed resistance to Mancozeb and Captan. Trichoderma pseudokoningii is susceptible to these fungicides. However, when increased the concentration of Mancozeb and Captan decreased the radial growth. Trichoderma species are stronger antagonistic against number of plant pathogens and their mycoparasitic activity. All Trichoderma species inhibited the mycelial growth of Alternaria alternata while maximum inhibition performed by T. viride . Trichoderma koningii was highly antagonistic over Rhizoctonia solani followed by T. viride . Radial growth of Aspergillus niger was highly inhibited by T. koningii followed by T. harzianum . Geotrichum candidum was inhibited significantly by T. viride followed by T. pseudokoningii and T. virens . Significant antagonism was exhibited by T. virens against Fusarium oxysporum f. sp. spinacae followed by T. harzianum and T. pseudokoningii . Radial growth and sporulation of Macrophomina phaseolina was antagonized significantly by T. viride followed by T. harzianum and T. pseudokoningii .