K. T. KOBRA,
M. R. ALI & T. AKTER*
Abstract
An
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 consisted 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 and coriander
were used as intercrops. The experiment was laid out in a Randomized Complete
Block Design (RCBD) with three replications. The overall result indicated that
the trap crop and intercrop combination system with cabbage decreased the
incidence of insect pests of cabbage whereas, increased the abundance of
beneficial arthropods compared to sole cropping of cabbage. 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 observed
in T8 treatment. This treatment also showed the highest number of
insect species and diversity index in early, mid and late vegetative stages).
Keywords: Biodiversity,
Arthropods, Cabbage, Trap Crops, Intercropping System.
