SCREENING OF RICE VARIETIES (AUS) AGAINST Rhizoctonia solani CAUSING SHEATH BLIGHT OF RlCE

Abstract

An experiment was conducted in the field of SAU (Sher-e-Bangla Agricultural University) farm, Dhaka to screen out the resistant varieties of rice against sheath blight (Rhtzoctonia solani kuhn) during Aus season in 2007. Seven rice (Aus) varieties viz. BR3, BR14, BR16, BR2I, BR26 and BRRI dhan 27 were used as treatments. The screening of the varieties were done based on different parameters like disease incidence, disease severity, yield and yield contributing characters. The highest lesion size was recorded in the variety BR16 (4.02 em) and lowest lesion size (3.50 em) was in BRRI dhan 27 at maturity stage. The value of the relative lesion height (%RLH) was large in the susceptible variety and small in the moderately susceptible variety. Among the varieties, BR3, BRi4, BR2I, BR24, BR16 and BR26 were graded as susceptible and BRRI dhan 27 was graded as moderately susceptible to sheath blight. The disease was more severe in advanced growth stages of the plants. The highest grain yield per hectare (3.00 tJha) was recorded in the variety BRRI dhan 27 and the lowest grain yield (1.14 tlha) was recorded in the variety BR24. The highest weight of thousand grains (32.73 gm) was recorded in the variety BRRI dhan 27 and the lowest weight of thousand grains (29.43 gm) was recorded in the variety BR3. BRRI dhan 27 performed better in respect of all the parameters considered against sheath blight of rice.