Germplasm evaluation of chrysanthemum for resistance to aphid, Macrosiphoniella sanbornii (Gillette)

Forty eight germplasm/varietal collections of chrysanthemum were evaluated for resistance to aphid, Macrosiphoniella sanbornii (Gillette) under polyhouse conditions during 2003–05 at Indian Institute of Horticultural Research, Bangalore. Genotype response was studied in terms of the number of aphids per terminal shoot and bud and the percent shoot infestation of aphids. Significant variations of aphid infestation were recorded among genotypes. Seven genotypes viz., ‘Aparajitha’, ‘Asha’, ‘F-52’, ‘Heritage’, ‘PC-31’, ‘Punjab Anuradha’ and ‘Rangoli’ were least susceptible (<5 aphids/shoot) to aphid. Among the rest, 12 collections were moderately susceptible, 21 were susceptible and 8 were highly susceptible (>25 aphids/shoot). A comparison of indigenous and exotic genotypes in their response to aphid indicated the superiority of former in being least susceptible to aphid.