Abstract: Brassica crops are the most diversified and largest oilseeds produced by Pakistan and other countries of the world. Different species of aphids are the most devasting pests of Brassica campestris L., due to sucking of cell sap from leaves, stem, flowers and pods by both nymphs and adults insect. Study was conducted to examine resistance and susceptibility of eighteen B. campestris genotypes based on population density of aphids and grain yield under the same field environmental factors. The treatments were laid out in randomized complete block design in thrice replications. The trial was propagated as per the recommendations of agriculture and kept unsprayed. The most serious problematic insect pest at study site causing severe crop infestation was aphid Myzus persicae (Sulzer) (Homoptera: Aphididae) throughout the season. All genotypes had shown different levels of resistance and susceptibility to variable level of aphid infestation. High yielding genotypes were found comparatively more tolerant to aphids, whereas, severely damaged had given less produce. The genotypes NM-1, NM-2 and NM-3 were comparatively completely resistant with no population of aphids, showed the highest yield potential and did not differ significantly from one another. The genotypes DLJ-3, Chaliate and E-9 showed susceptible response and appeared comparatively the lowest yielding. Resistant genotypes can be grown as a component of an integrated pest management strategy for protecting the B. campestris crop from aphid infestation to reduce the use of expensive, toxic and environmentally damaging pesticides.
Keywords: Aphids Management, Brassica campestris, Myzus persicae, Tolerance, Pest.