Reaction of rapeseed varieties to aphid Abstract

• Main Authors: A`li Niya, Faramarz, Rabi`i, Mohammad
• Format: Publication
• Language: Persian
• Published: Rasht (Iran) Rice Research Institute of Iran 2009
• Subjects: APHIDIDAE; BRASSICA NAPUS; BRASSICACEAE; BREVICORYNE BRASSICAE; ENSAYOS DE VARIEDADES; ESSAI DE VARIETE; Gilan ( Province ); GRAINE DE COLZA; http://www.fao.org/aos/agrovoc#c_1066; http://www.fao.org/aos/agrovoc#c_16196; http://www.fao.org/aos/agrovoc#c_1982; http://www.fao.org/aos/agrovoc#c_25499; http://www.fao.org/aos/agrovoc#c_26833; http://www.fao.org/aos/agrovoc#c_30769; http://www.fao.org/aos/agrovoc#c_525; PESTS OF PLANTS; PLAGAS DE PLANTAS; RAPESEED; RAVAGEUR DES PLANTES; SEMILLA DE COLZA; VARIETY TRIALS

Resistance of Rapeseed varieties (Brassica napus L.) to cabbage aphid (Brevicoryne brassicae) was studied in rice research institute during 2001-4 with natural and artificial infestation. In natural infestation, 25 varieties were studied in lattice design with 3 replications and sampling was done with counting the numbers of the aphid in top, middle and down leaves and 20 cm top branches. The artificial infestation experiment was arranged in a completely randomized block design with three replications. Varieties were cultivated after rice harvest in early November. For infestation of varieties, colony of cabbage aphid was reared in glasshouse. Three thousands aphids were released for each treatment. To prevent plant infestation by other pests and entering natural enemies of the aphid, each plot was covered by a net cage. Sampling was done three times and infested stem length was sampling unit. Total numbers of infested stem length was measured for each treatment. Yield components, grain yield, thousand-seed weight and oil percentage were compared in different treatments. Results showed that there were not significant differences between varieties and very few aphids were found in all varieties in natural infestation. For artificial infestation experiment, Kristinia variety had the highest mean of infested stem length while Hyola 308, Hyola 401 and RGS 003 had the least infested stem length. Highest damage was observed in yield components in option 500 and Kristinia while Hyola 308 and RGS 003 had the least damage. Option 500, Kristinia and PF 7045/91 had highest damage in thousand-seed weight and Hyola 308 and RGS 003 had the least damage. Therefore, tested varieties showed different reactions to the aphid infestation and there were significant differences in damage and tolerance.