Potential of Trichoderma spp. as biocontrol agents against pathogens causing maydis leaf blight of maize

摘要

Efficacy of bioagents against Helminthosporium maydis was studied in vitro and under field condition at Trihut college of Agriculture, Dholi (Muzaffarpur) in 2005 and 2006. Among the three native antagonist isolates of Trichoderma viride. Trichodermaharzianum and T. virens screened, T. viride inhibited the radial growth of//, maydis to an extent of 60.7% followed by T. harzianum (55.1%) and T. virens (52.6%). Studies on hyphal interaction between antagonists and test fungus revealed disorganizationof protoplasmic content and lysis of host hyphae. Soil application of bioagents was more effective in protecting the crop than foliar spray. Soil application of T. viride resulted in minimum disease intensity (2.6) followed by T. harzianum (2.8) and T. virens (3.0). Soil application of T viride also gave maximum yield (18.6q ha~(-1)) followed by T. harzianum (17.7q ha~(-1)) and T. virens (17.3q ha~(-1)), respectively. These results suggest the need to augment soil application of Trichoderma for obtaining effective management of maydis leaf blight.