Effect of sowing dates on the abundance and infestation of aphid and sawfly in mustard field

Effect of sowing dates on the infestation of aphid and sawfly

Abstract

Mustard (Brassica sp.) is an important oilseed crop in Bangladesh, often infested with aphid (Lipaphis erysimi (Kaltenbach)) and sawfly (Athalia lugens proxima (Klug)), causing significant yield loss. This study evaluated the effect of sowing dates and methods on pest infestation, growth, reproductive traits and yield of mustard (BARI sarisha-14) at Gazipur Agricultural University from November 2022 to March 2023. six treatments were tested: T1 (15 November, broadcasting), T2 (15 November, line), T3 (1 December, broadcasting), T4 (1 December, line), T5 (15 December, broadcasting), T6 (15 December, line) in a randomized complete block design with three replications. Vegetative growth was the highest in T2 (61.4±3.7 cm height, 6.0±1.0 branches, 27.8±1.8 leaves, 62.7±2.9 mm² leaf area) and lowest in T5 (46.8±3.3 cm, 2.0±0.0 branches, 18.6±1.1 leaves, 48.2±1.9 mm²). Reproductive traits followed the same trend. Pest infestation was lowest in T2 (aphid 97.4±5.1 per 10 shoots; sawfly 2.7±0.2 plot-1) and highest in T5 (aphid 143.9±4.3; sawfly 4.5±0.1). Seed yield and harvest index were highest in T2 (1.44±0.4 MT ha-1, 30.0±1.3%) and lowest in T5 (0.59±0.1 MT ha-1, 24.0±1.3%). Early line sowing improved growth, reduced pest pressure, and increased yield, offering a practical strategy for sustainable mustard production in Bangladesh.

Ann. Bangladesh Agric. 30(1): 117-130