RELATIVE ABUNDANCE OF APHIDS POPULATION ON DIFFERENT BRASSICA GENOTYPES

Twelve Brassica genotypes i.e. Westar, Ganyou-5, Rainbow, Oscar, Vangard, Crusher, Torch, Legend, Altex, Raya Anmol, Peela Raya and T-16-401 representing four Brassica species including B. napus, B. juncea, B. carinata and B. campestris were tested for aphid’s density and yield in the Research Farm of The University of Agriculture, Peshawar, Pakistan. Data on aphid’s density showed that average aphid’s density per plant on 12 brassica genotypes during 2006-07 and 2007-08 was at peak during the 2nd and 3rd weak of January. The aphid density 37.94, 34.87, 30.47, 27.57, 26.86, 25.39, 24.89, 23.55, 23.41, 21.57, 18.42 and 12.84 aphids plant-1) were recorded on Legend, Ganyou-5, Oscar, Raya Anmol, Rainbow, Torch, T-16-401, Peela Raya, Westar, Altex, Crusher and Vangard, respectively. Statistically there were significant differences in the number of aphids per plant among the genotypes. Non of the genotype was found completely free from aphids attack. Vangard with minimum (12.84) aphids /plant was the most tolerant followed by Crusher, Altex, Westar, Peela Raya, T-16-401, Torch, Rainbow, Raya Anmol, Oscar, Ganyou-5 while Legend as most susceptible, in the order. Peela Raya had moderately high density of aphids per plant.