EVALUATION OF THE APHID INFESTATION ON SOME OF SELECTED MUSTARD VARIETIES AND ITS CHEMICAL CONTROL

Abstract

The experiment was conducted in the central farm of Sher-e-Bangla Agricultural University, Dhaka-1207, during the period from November 2015 to February 2016 to evaluate the infestation level of mustard aphid against the combination of chemical treatment and varieties. The experiment comprised of two factors (4 variety and 3 levels chemical); Factors A: Mustard varieties (4 mustard varieties) i) V1=BARI Sarisha-11 ii) V2= BARI Sarisha-14 iii) V3= BARI Sarisha-15 and iv) V4= BARI Sarisha-16; and Factor B: chemical treatment (3 levels) viz. i) T1= Ripcord 10 EC @1mlL-1 water ii) T2= Imitaf 20 SL @1mlL-1 water and T3= Marshal 20 EC @1mlL-1 water The experiment was laid out in a Randomized Complete Block Design with four replications. At early flowering stage, the lowest number of aphid (4.66) observed from V4 and T2 (6.12). At late flowering stage, the lowest number of aphid (7.39) observed from V1 and the lowest number of aphid (7.33) observed from T2. The lowest number of aphid (5.39) observed from V4T2 and the highest number of aphid (13.80) observed from V4T1. At early fruiting stage, the lowest number of aphid (4.01) observed from V4 and the lowest number of aphid (9.00) observed from T2. The lowest number of aphid (6.61) recorded V4T2. At late fruiting stage, the lowest number of aphid (5.67) observed from V4 and the lowest number of aphid (7.43) recorded from T2. The lowest number of aphid (5.46) observed from the V4T2. At flowering stage, the highest number of healthy plants (31.99) and the lowest infested plant (6.39%) recorded from V4 and the highest number of healthy plants (28.91) and the lowest infested plant (4.78%) found from T2. The highest number of healthy plants (33.97) and the lowest infested plant (5.20%) observed V4T2. At fruiting stage, the highest number of healthy plants (32.51) recorded from V4, whereas the lowest number of healthy plants (23.40) found from V2 again the highest number of healthy plants (29.62) and the lowest infested plant (6.21%) found from T2. The highest number of healthy plants (33.97) and the lowest infested plant (5.05%) observed V4T2. The longest plant (178.78 cm), maximum number of siliqua plant-1 (179.57) and longest siliqua (7.39 cm) found from V4. The longest plant (123.56 cm), maximum number of siliqua plant-1 (119.56), longest siliqua (6.35 cm) observed from T2. The longest plant, maximum number of siliqua plant-1, longest siliqua found from V4T2 , while the shortest observed from V2T3. The highest seed yield (2.21 t ha-1) found from V4 and the lowest seed yield (1.31 t ha-1) observed from V2. The highest seed yield (1.87 t ha-1) observed from T2 and the lowest seed yield (1.70 t ha-1) found from T3. The highest seed yield (2.30 t ha-1) found from V4T2.