Evaluation of Different Brassica Species Against Mustard Aphid, Lipaphis erysimi

Three hundred eighty eight germplasm accessions of different species of Brassica viz. B. juncea (133 accessions), B. rapa var. yellow sarson (102), B. rapa var. toria (58), B. rapa var. brown sarson (32), B. nigra (24), B. napus (18), B. tornefortii (16) and close relative, Lepidium sativum (5) in augmented block design were screened for tolerance against mustard aphid (Lipaphis erysimi) under field conditions at New Delhi, India, during Rabi 2009–10. The screening was done based on the parameters of aphid infestation index and aphid population count. The differential reaction of germplasm accessions ranged from highly susceptible to highly tolerant. The percentage of highly tolerant and tolerant accessions in different species of Brassica ranged from 5% in B. rapa var. toria, to 100% in the closely related species, L. sativum. Based on the mean aphid infestation index the aphid tolerance in different species was in the descending order of L. sativum> B. nigra > B. juncea > B. napus > B. tournefortii>B. rapa var. yellow sarson > B. rapa var. brown sarson> B. rapa var. toria. Sixty three accessions of different species of Brassica were found highly tolerant and tolerant to aphid infestation.