STUDY ON SOME MORPHOLOGICAL AND PHYSIOLOGICAL FEATURES OF STEMPHYLIUM BOTRYOSUM CAUSING STEMPHYLIUM BLIGHT DISEASE OF LENTIL AND ITS CONTROL

Abstract

xperiments were carried out to study on some morphological and physiological features of Stemphylium botryosum causing Stemphylium blight and its control with fungicides and' antagonist both in vitro and in vivo at Plant Pathology Division, Bangladesh Agricultural Research Institute, Joydebpur, Gazipur during the period of September'07 to April'08. The experimental design was CRD in lab condition and RCBD in field condition having five and four replications, respectively. The colony color of S. botryosum was greenish brown, irregular margin and velvety texture on PDA medium. The suitable temperature and pH for the maximum colony growth was 25°C and 6.0, respectively. The maximum (100%) germination of conidia was found at 25°C after 6 h of incubation. In the in vitro test, six fungicides viz. Iprosun 50WP, Edcuzeb 80WP, Proud 2SEC, Rovral SOWP, Emivit 50WP and Agrirnyl had the potentiality to inhibit the radial mycelial growth even at a lower (500 ppm) concentration except Agrimyl (Mancozeb + Metalaxyl) that inhibited radial colony growth at higher (2000 ppm) concentration. In field condition the minimum disease score (1.0) was recorded in Iprosan SO WP treated plot and the highest (4.75) was found in control' plot. Among the six fungicides Iprosan SOWP from the iprodione group gave the best performance and yielded the highest root length (9.48 ern), shoot length (~.6 em), number of branches plant" (9.2S), number of pods plant" (39.10), thousand grain weight (21.08 g) and grain yield (1271.00 kg ha").