Host Plant Resistance and Population Dynamics on Different Genotypes of Cabbage against Diamondback Moth, Plutella xylostella in Faisalabad, Pakistan

The studies on the host plant resistance of different genotypes of cabbage against Diamondback Moth (DBM), Plutella xylostella (L.), were carried out for two consecutive years, viz., 2007 and 2008 at a farmer's field in Faisalabad (Chak No. 204), Pakistan. Fifteen genotypes of cabbage viz. Green Challenger, Summer Green, Green Globe, Asha, Takila, BC-305, Zennith, Pruktor, Domon, HTCV-9089-08, SSP-2200, KS-Cross, CB-60, Clandia F1,H, Broccoli and Adavanta were tested for their relative resistance/susceptibility as a preliminary study during 2007 and then categorizing them resistant, intermediate and susceptible in final screening trial during 2008. All the cultivars of cabbage during 2007 as well as during 2008 showed significant difference among themselves at P less than 0.01. Green Challenger, Summer Green and Green Globe were susceptible during 2007, while Adavanta, Clandia F1, H, Broccoli and CB-60 appeared as resistant with pest's population ranging from 6.17 to 6.25 and 1.27 to 1.46 larvae per 20 leaves, respectively. Domon, Pruktor, Zennith appeared as intermediate with larval population range of 2.67 to 2.73 per 20 leaves. Similar trend was also observed during 2008 i.e., Green Globe, Green Challenger and Summer Green showed susceptible response with larval population range of 7.19 to 7.50 per 20 leaves. CB-60, Clandia F1, H, Broccoli and Adavanta 1402 appeared as resistant with larval population range of 1.85 to 2.21 per 20 leaves. The month of November was peak infestation time in both years on all genotypes. The results are discussed in relation to ealier documented incidence of DBM on cabbage. [copy 2012 Friends Science Publishers