BIOLOGICAL CONTROL OF COLLAR ROT OF TOMATO CAUSED BY Sclerotium rolfsii

Abstract

A study was carried out in the laboratory and under field condition to find out the effectiveness of Trichoderma harzianum as a boiagent for controlling collar rot (Sclerotium rolfsii) of tomato. The pathogen was collected from naturally infected tomato plant and isolated by tissue planting method. Fomulated Trichoderma harzianum was collected from IPM Laboratory, Department of Plant Pathology, Bangladesh Agricultural University, Mymensingh. The 7richoderma harzianum showed excellent effect in controlling collar rot disease of tomato in field experiment. The maximum emergence of lesion size (9.003 mm) was observed in tomato plants inoculated with only S. ro/fsii. The minimum emergence of lesion size (2.900 mm) was observed in bio-fungicide treated plots. The highest total mortality (61.11%) was recorded in S. rolfsii inoculated plots and the lowest (24.07%) was in bio-fungicide treated plot. The plant height, number of inflorescence, number of branches and number of fruits per plant were the highest in bio-fungicide treated plots, while the minimum in S. rolfsii inoculated plots. Trichoderma harzianum treated plots resulted the highest yield performance (27.23ton/ha) as compare to Sclerotium rolfsii inoculated plots (10.28 ton/ha).