FUNGICIDAL MANAGEMENT OF BLAST (Pyricularia grisea) OF AMAN RICE

Abstract

Blast is a first most important disease of rice caused by Pyricularia grisea (Cooke) Sacc, occurs in all parts of Bangladesh. An experiment was carried out in the field of Plant Pathology, Hajee Mohammad Danesh Science & Technology University, Dinajpur during the period of July-December 2009. Three sprays of Bavistin 50 WP, Tilt 250 EC and Folicur EW 250 with control were evaluated against the disease on three aman varieties viz. Hybrid Hera, BRRI Dhan-49, BR-11. Data were collected on leaf blast severity, neck blast infection and yield. The highest percent leaf blast area infection (22.08%) was found in BR 11 but the lowest (17.40%) was recorded in BRRI dhan-49. The Hybrid Hera was showed the severity (18.63%) what was in-between of BR-11 and BRRI Dhan-49. The highest percent leaf area infection (24.69) was observed in control plot and the lowest percent leaf area infection (15.23) was observed in the Folicur EW 250 sprayed plot. The leaf blast severity was decreased (38.31%) in the Folicur EW 250 sprayed plot over control. The highest neck blast index (19.77) was recorded in BR-11 whereas the lowest (13.16) was recorded in BRRI Dhan-49. The highest (22.84) neck blast index was found in control and the lowest neck blast index (12.85) was recorded in Folicur EW 250 sprayed plot. The neck blast index decreased (43.73%) in Folicur EW 250 sprayed plot over control. The highest yield of unit area (0.60 kg) was recorded in the BR-11 variety and the lowest yield per unit area (0.54 kg) was recorded in the Hybrid Hera variety. The highest and lowest yield were recorded in Folicur EW 250 and Control plot, respectively. The highest yields (5.36 t/ha) was recorded in BR-11 variety and the lowest yield (4.45 t/ha) was obtained from the Hybrid Hera. In the fungicidal spray, the highest yield (t/ha) (5.58) was recorded in the Folicur EW 250 sprayed plot and the lowest yield (t/ha) (4.25) was recorded in the control plot. Finally it may be concluded that BR-11 was the best variety in aspect of yield, BRRI Dhan-49 showed the lowest blast disease severity and Folicur EW 250 was a promising fungicide for lowering blast disease incidence and significantly higher yield.