Effect of intercropping on the incidence of diamondback moth, Plutella xylostella (Linn.) on cauliflower

Effect of intercropping of cauliflower with tomato (Lycopesicon esculentum), radish (Raphanus sativus), carrot (Daucus carota), fennel (Foeniculum vulgare), coriander (Coriandrum sativum), cumin (Cuminum cyminum), garlic (Allium sativum), berseem (Trifolium alexandrium) and marigold (Tagetes tagetta) were studied on the infestation of P. xylostella during 2007 and 2008. The intercrops were sown 30-days earlier than sole crops and 40 days seedling of cauliflower were transplanted with spacing of 60x45 cm in a ratio of 15:1, 15:2, 25:1 and 25:2. 15:2 ratios was significantly more effective than 15:1 ratio and in the same manner 25:2 ratio of intercrop was more effective than 25:1. In sole crop the population of diamondback moth was found to be increasing from 15 to 75 DAT and then declined to 17.24 larvae and pupae/plant at 85 DAT. The fennel was more effective than other intercrops tested. 40-days old seedling holds less number of larvae and pupae of P. xylostella as compared to 30-days old seedling. Yield of cauliflower in different intercropping system was significantly varied and fennel gave a significantly (P