STUDIES ON YIELD LOSS AND MANAGEMENT OF BAKANAE DISEASE IN SEED BED

Abstract

The experiment was conducted at the experimental field of Plant Pathology Division of Bangladesh Rice Research Institute (BRRI). Gazipur during the period of Boro season from November 2007 to March, 2008 to study the yield loss and management of Bakanae disease in seed bed. The variety BRI was used as the test crop, In the seed bed. the experiment comprised the treatments of TI: Conza 0.3% (5 EC Hexaconazole) @ 1.5 ml/SOO ml water, T2: Sunconazole 0.3% (25 EC Propiconazole 25%) @ 1.5 ml/500 ml water; TJ: Nativo 0.3% (75 WG-Tebuconazole 50 + trifloxistrobin 250/0) @ 1.5 gl500 ml water: T4: Zeal 0.3% (75 WP-Tricyclozole) @ 1.5 g/500 ml water; Ts: Bavistin 0.3% (Carbendazim 500/0)@ 1.5 glSOOml water; T6: Biocontrol agent (bacteria) 300 ml water and T,: Control. In the field experiment, it was comprised of two factors. such as Factor A: Spraying number: 2 levels- 81: Single spray and 82: Double spray; Factor B: Control measures- T1: Bavistin @ 0.5%; T2: Bavistin @ 0.4%; T3: Bavistin @ 0.3%; T,,: Knowin @ 0.5%: Ts: Knowin @ 0.40/0~ T6: Knowin @ 0.3%~ T7: Seed treatment@ 0.3%) Bavistin; Ts' Seed treatment @ 0.30/0 Knowin: T9: Control only fresh water and T 10: Control without fresh water, In case of chemical control, the minimum nwnber of Bakanae infected seedlings (1.38 m-2 and 1.53 m-2) was found from T2 and. the maximum number (9,57 m'2 and 9.69 m-2) was recorded from T7. In case of spraying number, the minimum Bakanae infected seedlings (0.54 m-2 and 0.96 m-2) were recorded for 82• while the maximum number (0.72 m-2 and 1.19 m-2) was found from S" respectively. In case of control measures. the minimum Bakanae infected seedlings (0.09 m-2 and 0.13 m-2) were recorded from T7• while the maximum number (1.49 m-2 and 1.83 m") was found from TIO• In case of interaction effect of spraling number and control measures. the minimum Bakanae infected seedlings (0.07 m' and 0.12 m-2) were recorded from S2T7and the maximum number (1.62 m-1 and 1.87 m-2) was observed from SITlo. At 60,80 and 100 OAT, the minimum Bakanae infected hills (0.74 m'2 , 1.60 m-2 and 1.50 m") was obtained for S2, 'while the maximum number (0.84 mol, 1.77 m'2 and 1.82 m') was found from 51' The highest yield (3_52 t ha") was recorded from S2 while the lowest (3.11 t ha-1) was obtained from Sr. At 60,80 and 100 DAT, the minimum Bakanae infected hills (0_14 m-2, 0.39 m-2 and 0.50 m-2) were recorded from T7• while the maximum number (2 37 m", 3.33 and 3.35 m-2) was found from T9- The highest yield (3.47 t ha") was recorded from T7 and the lowest (3.13 t ha") was found from T9• At 60. 80 and 100 DAT, the minimum Bakanae infected hills (0.14 m-2~ 0.33 m'2 and 0.44 mol) were recorded from S2T7, again the maximwn number of Bakanae infected hills (2.44 m-2• 3.55 m-2 and 3.55 m-2) was recorded from SIT9• The highest yield (3.67 t ha-I) was recorded from 82T7• while the lowest (2.85 t ha-t) was found from SIT,o,