BIO-EFFICACY OF MICROBIAL ANTAGONISTS AGAINST FOOT AND ROOT ROT PATHOGEN(S) OF LENTIL

Abstract

The experiment was conducted in the Disease Diagnostic Laboratory of the Department of Plant Pathology, Sher-e-Bangla Agricultural University, Dhaka during the period of November 2011-February 2013 to determine the bio- efficacy of microbial antagonists against foot and root rot pathogen(s) of lentil. Two fungal genera namely Fusarium oxysporum and Sclerotium rolfsii were isolated from foot and root rot infected lentil plants. Seven seed treatment agents, viz., Rhizobium leguminosarum isolate 1, isolate 2, isolate 3, isolate 4, Pseudomonas fluorescens, Trichoderma harzianum and Control (sterile water) were used in this experiment. In dual culture method, highest zone of inhibition of F. oxysporum (57.37%) was measured against R. leguminosarum isolate 3 and isolate 4. In case of S. rolfsii, 80.00% and 31.85% zone of inhibition were measured' against P. jluorescens and T. harzianum, respectively. In rolled paper towel method, the highest germination (91.00%) and lowest dead seeds (9.00%), no abnormal and diseased seedlings were counted from seeds treated with R leguminosarum isolate I. The maximum vigor index (1390.00) was observed in P. fluorescens treated seeds. In water agar test tube method, the highest germination (88.00010) and lowest dead seeds (11.67%) were counted from R. leguminosannn isolate 4 treated seeds. The maximum number of normal seedlings (84.56) and minimum number of abnormal seedlings (2.00) were counted from seeds treated with R. leguminosarum isolate 1 and isolate 2, respectively. The minimum number of diseased seedlings (0.61) were counted from T. harzianum treated seeds.