BIODIVERSITY OF INSECT PESTS AND OTHER ARTHROPODS IN CABBAGE FIELD USING TRAP CROPS AND INTERCROPPING SYSTEM

Abstract

The experiment was conducted in the field of Sher-e-Bangla Agricultural University farm, Dhaka, Bangladesh during the period from October 2016 to February 2017. The experiment consists of twelve treatments such as T1: Cabbage plus Mustard; T2: Cabbage plus Radish; T3: Cabbage plus Onion; T4: Cabbage plus Garlic; T5: Cabbage plus Coriander; T6: Cabbage plus Mustard plus Onion; T7: Cabbage plus Mustard plus Garlic; T8: Cabbage plus Mustard plus Coriander; T9: Cabbage plus Radish plus Onion; T10: Cabbage plus Radish plus Garlic; T11: Cabbage plus Radish plus Coriander; T12: Sole Cabbage. In this study, the mustard and radish were used as trap crops. On the other hand, the onion, garlic as well as coriander were used as intercrops. The experiment was laid out in Randomized Complete Block Design (RCBD) with three replications. The overall result indicates that the trap crop and intercrop combination system with cabbage decreased the incidence of insect pests of cabbage and increased the abundance of beneficial arthropods compared to sole cropping of cabbage. The lowest percent leaf infestation was caused by diamondback moth caterpillar (3.20%), cabbage semi-looper (0.29%) and tobacco caterpillar (1.37%) in T8 treatment. Conversely, the highest number of beneficial arthropods per plot such as natural enemies viz. lady bird beetle (4.83), staphylinid beetle (1.49), hover fly larvae (3.92), dragon fly (1.68), ground beetle (0.61), ant (3.10), spider (1.11) as well as pollinators viz. honey bee (31.10), carpenter bee (1.30) and hover fly (5.22) were also recorded in T8 treatment. The highest cabbage yield (39.85 ton/ha) was produced in T8 treatment. These findings illustrated that, the combination of Cabbage plus Mustard plus Coriander was more effective for enhancing population of beneficial arthropods such as pollinators and natural enemies as well as suppressing the insect pests of cabbage. So, the trap crop and intercropping system was an eco-friendly pest management practice for cabbage by which one can significantly reduce pest infestation without use of any chemical insecticides.