Selection of Fungi Associated with Soybean Seed for Controlling of Soybean Anthracnose

Abstract

etection of seedborne fungi in 6 cultivars of soybean seed samples was conducted by using Blotter Method. Twenty fungal isolates were found and identified to be in 12 genera. Cladosporium sp., Cercospora sp., Penicillium sp., Aspergillus niger, Macrophomina phaseolina. Cladosporium sp. were found at the highest percentage in cultivars CM 1, CM2, CM 60, SJ 4, SJ 5 and Doi Kham respectively. Sixteen isolates of all which grew well were tested in vitro on efficacy of being antagonist, to inhibit growth of Colletotrichum truncatum causing anthracnose disease of soybean, using Dual Culture Technique. It was found that the isolate of Trichoderma sp. gave higher percentage of growth inhibition (80.05%). This fungus showed its capability of parasite by penetrating its mycelium into the pathogen's mycelium, grew inside and then made the mycelium collapsed. Comparison on effectiveness of Trichoderma sp. and the thiram fungicide in controlling C. truncatum on soybean seed, cultivar CM 2, by seed dressing. It was found that both Trichoderma and thiram reduced incidence of diseases and enhanced increasing the percentage of seed germination but thiram showed higher effectiveness, significant difference than Trichoderma.