Two field trials were carried out to study the effect of intercropping and cow-urine plant extracts on the incidence of Pieris brassicae Linnaeus, Plutella xylostella Linnaeus and Brevicoryne brassicae Linnaeus in cabbage. The results revealed that the minimum incidence of P. brassicae, P. xylostella and B. brassicae was observed in cabbage intercropped with marigold registering mean population of 4.02, 4.20 and 50.70 insects/plant, respectively, and maximum population was recorded when cabbage grown with broad bean recording mean population of 8.23, 9.87 and 63.40 per plant, respectively compared 11.24, 9.92 and 71.47 per plant on cabbage as sole crop. The plots of cabbage intercropped with marigold yielded highest (17.30 t/ha) with net-return of Rs 51, 900/ha followed by tomato (Rs 50, 100/ha) and garlic (Rs 46,050/ha) with their corresponding additional return over cabbage sole crop of Rs 54300, Rs 49,550 and Rs 28, 200/ha, respectively. The results of insecticidal evaluation indicated that the plots treated with dichlorvos at 500 a. i/ha resulted in significant reduction of butterfly, moth and aphid recording lowest incidence of 1.11, 4.16 and 11.64 insects/plant compared to 11.40, 19.71 and 40.23 insects/plant, respectively in untreated control plots. Dichlorvos was at par with calpaste at 1, 500 g/ha for P. brassicae, while it was at par with Jatropha gossypifolia extract at 12500 ml/ha for P. xylostella. The treatments with V. trifolia and Acorus calamus showed their inferiority over rest of the test compounds with a record of maximum butterfly larvae, moth larvae and aphid population. The highest mean yield (23.51 t/ha) was recorded from dichlorvos treated plots followed by the plots treated with calpaste (22.76 t/ha), cal-10 (21.95 t/ha), Melia azedarach (21.21 t/ha), cal-MB (20.11 t/ha) and J. gossypifolia (19.60 t/ha) compared to 17.63 to 18.11 t/ha in the rest of the five insecticidal treatments and 13.95 t/ha in untreated control. The extent of avoidable yield loss due to the incidence of butterfly, moth and aphid was estimated to be 40.66% in untreated check which was reduced to 3.19 (calpaste) -24.67% ( A. calamus) in different insecticidal treatments.
