Effect of Trap Cropping of Brassica juncea (Linn.) on the Management of Lipaphis erysimi (Kalt.) on B. oleracea var. capitata (Linn.)

During the rabi of 2022-23, Indian mustard cv. Laha 101 was used as a trap crop to manage the mustard aphid, Lipaphis erysimi (Kalt.) on cabbage cv. K-1. The results showed that trap cropping ratios significantly lowered aphid densities compared to the sole crop (cabbage). The lowest density of aphids (4.60 aphid/plant) was recorded in cabbage under the trap cropping ratio of 3:2. On the other hand, the peak infestation (19.05 aphid/plant) occurred on the mustard of the same trap cropping ratio (3:2) when compared with other trap cropping ratios on 7th SMW (February 11th). Even though the sole crop (cabbage) had the highest aphid density (28.13 aphid/plant), it yielded 49.23 t/ha and had a benefit cost ratio of 2.07 due to two sprays of insecticide (Malathion 50 EC), which was not done in the trap cropping ratios. Thus, the trap cropping ratio of 3:2 (2.31) had the best cost benefit ratio followed by the trap cropping ratio of 1:1 (2.19), which recorded produce of 42.61 t/ha and 41.29 t/ha respectively. Overall, the use of Indian mustard cv. Laha 101 has been shown to be effective as a trap crop in managing mustard aphid on cabbage cv. K-1 during the rabi season. By using the correct trap cropping ratio, farmers can maximize their produce while minimizing the use of insecticides, which can be beneficial both economically and environmentally.