EVALUATION OF SOME POPULAR MUSTARD VARIETIES AGAINST APHID AND SAWFLY ATTACK UNDER FIELD CONDITION

Abstract

A field experiment was conducted at Sher-e-Bangla Agricultural University, Dhaka during the period from November 2020 to April 2021 in Rabi season, to evaluate some popular mustard varieties against aphid and sawfly attack under field condition. The experimental treatments were consisted of two factors, and followed by randomized complete block design with three replications. Factor A. mustard varieties (3) viz; V 1 = BARI sharisha-1, V 2 = BARI sharisha-9 and V 3 = BARI sharisha-14 and Factor B: different biorational pesticides (3) viz; P 0 = untreated (Control), P 1 = Confidor 70 WG (imidacloprid) @ 0.2 g/L of water, and P 2 = Tracer 45 SC (spinosad) @ 0.4 ml/L of water. The result of present studies related to the incidence of insect pests and its natural enemies revealed that the populations of mustard sawfly, mustard aphid and other insect-pests were ranged between 0.33 to 2.33 (larvae/plant), 0.33 to 55.33 (aphids/10 cm central twig/plant), 0.33 to 2.67 (insect-pests/plant), respectively. The population of Coccnella spp., syrphid fly, spider and other predators was ranged between 0.33 to 4.00 (larvae and adults/plant), 0.33 to 3.67 (larvae/plant), 1.00 to 2.67 (spiders/plant) and 0.33 to 2.33 (predators/plant), respectively. The major pest i.e. mustard aphid showed a significant positive correlation with coccinellids, spiders and others. However, a non-significant correlation of mustard sawfly appeared with coccinellids, Syrphid fly, spiders and others. The population of mustard sawfly and aphid reduced due to the application of biorationals pesticide and different mustard varieties treatments. The highest seed yield plot -1 (0.36 kg) was observed in V 3

(BARI sharisha-14) treatment. Among different biorational pesticide, application of Confidor 70 WG (imidacloprid) @ 0.2 g/L of water recorded the highest the seed yield plot -1 (0.51 kg). Among different treatment combination, V 3 P 1 treatment combination performed best, recorded higher seed yield plot -1 (1.57 ton/ha) and was found superior overall other varieties and botanical to significantly minimum insect-pests incidence, high reduction percent and higher seed yield production of mustard comparable to other treatment combinations.