EFFECT OF INSECTICIDES APPLICATION TIMING ON INSECT PEST ATTACK, GROWTH, YIELD AND NUTRIENTS CONTENT OF MUSTARD

Abstract

The present experiment was carried out at Sher-e-Bangla Agricultural University research farm, Dhaka during the period from October 2020 to March 2021 to study the effect of insecticide application timing on insect pest attack growth, yield and nutrient content of mustard. Five treatments viz. T (Control; without insecticide application (control), T 1 ii 0 (Aktara; Thiamethoxam 25WG application in morning), T

(Aktara; Thiamethoxam 25WG application in afternoon), T (Celcron; Profenofos 50EC application in morning) and T 4 3 (Celcron; Profenofos 50EC application in afternoon) were considered for the present study. Treatments were applied at 30 days after sowing. The experiment was laid out in Randomized Complete Block Design with three replications. The maximum effectiveness was found from the treatment Aktara (Thiamethoxam 25WG) application in afternoon whereas Celcron (Profenofos) 50EC application in morning showed least performance in controlling insect of mustard compared to control. At 24, 48, 72 and 96 hours of spray, Celcron (Profenofos) 50EC application in morning

showed the lowest incidence of insect plot

(18.40, 25.33, 42.67 and 63.33, respectively). In case of mortality of insect, at 24, 48 and 72 hours of spray, the highest number of dead sawfly (21.67, 14.33 and 3.33 plot 1 , respectively) and dead aphid (48.33, 33.00 and 11.33 plot -1 , respectively) was recorded from Aktara (Thiamethoxam 25WG) application in afternoon but the number of dead bee (37.33, 24.33 and 7.00 plot -1 , respectively) was highest from the treatment Aktara (Thiamethoxam 25WG) application in morning whereas the lowest mortality was found from the treatment Celcron (Profenofos) 50EC application in morning for sawfly and aphid but the lower mortality of bee was found from Aktara (Thiamethoxam 25WG) application in afternoon and Celcron (Profenofos) 50EC application in afternoon. Similarly, the highest number of flowers plant (126.00), number of pods plant -1 (112.70), number of seeds pod -1 (37.67), 1000 seed weight (4.10 g), seed yield ha -1 (1.87 t) and % oil content (40.33%) were recorded from Aktara (Thiamethoxam 25WG) application in afternoon. The maximum K content in seed (1.244%) was found from Aktara (Thiamethoxam 25WG) application in afternoon compared to control. It can be concluded that the treatment Aktara (Thiamethoxam 25WG) application in afternoon showed effective performance against insect of mustard followed by Celcron (Profenofos) 50EC application in afternoon. Again, it was also observed that application of insecticide in the afternoon was more effective than application of insecticide in the morning for both the insecticide of Aktara and Celcron 50EC.