EFFICACY OF SOME MANAGEMENT PRACTICES AGAINST INSECT PESTS COMPLEX OF BRRI dhan50

Abstract

The experiment was conducted in the experimental area of Sher-e-Bangla Agricultural University, Sher-e-Bangla Nagar, Dhaka during the period from November 2014 to May 2015 to evaluate the efficacy of some management practices against insect pest complex of BRRI dha50. BRRI dhan50 were used as the test crop in this experiment. The experiment comprised of the following control measure as treatment- T1 = Spraying Diazinon 60EC @ 2ml/Litre of water sprayed at 7 days interval; T2 = Spraying Suntap 50 WP @ 1.2g/Litre of water at 7 days interval; T3 = Applying Mechanical control at 7 days interval; T4 = Applying Cultural control at 7 days interval and T5 = Untreated control. The experiment was laid out in a randomized complete block design (RCBD) with three replications. Data was recorded on pest incidence, number of healthy, infested plants & leaf for different pests and infestation level and also yield contributing characters and yield of BRRI dhan50 and significant variations was observed for different treatments. Data revealed that 8 common species of insect pests were found in rice field and they were belongs to 7 family under 6 orders. Among the insect species 2 species belong to the family Pyralidae. Insect population for 5 selected hills/plot were observed with clean observation and in the experimental plot yellow stem borer, leaf folder, rice hispa, grasshopper, brown plant hopper, green leaf hopper, rice bug and rice stink bug was observed and the highest number of the insect pests was recorded from T5, whereas the lowest number of these insect pests was observed from T2 treatment. In case of tillers, leaf and panicle infestation in different crop stages caused by different rice insect pests, the lowest infestation was recorded from T2, whereas the highest infestation was observed from T5. In consideration of yield contributing characters and yield of BRRI dhan50, the maximum number of filled grains (93.74) was recorded from T2, while the minimum number of filled grains/panicle (84.77) from T5. The highest grain yield (5.67 t/ha) was recorded from T2, while the lowest grain yield (3.35 t/ha) from T5. Among the different control measures, spraying Suntap 50 WP @ 1.2g/ Litre of water at 7 days interval was the better for the controlling of insect pest complex of BRRI dha50.