A study on common bean cultivars to identify sources of resistance against the black bean aphid, Aphis fabae Scopoli (Hemiptera: Aphididae)

Abstract

Black bean aphid is an important common bean pest in the world. Aphids damage crops both directly by their feeding and by spreading viruses. Also, they indirectly damages with excretion honeydew and smokes moulds growth through some physiological processes and transmission of viruses. Resistant cultivars application is the main strategy to control Aphis fabae Scopoli. In this experiment, different lines and cultivars were infested with five wingless adult aphids. After 7 and 14 days, plants were evaluated and aphid population was counted and recorded. After 45 days when plants reached to the flowering stage, test was repeated. Result showed that there was a significant difference among cultivars in number of adult aphid in two-leaf stage. Most of the number of adult at the first week in two-leaf stage observed on Goynok cultivar that had significant difference to other lines and cultivars. Number of adults and nymphs among the line and cultivar at flowering stage did not show significant difference. Number of deployed aphids after two weeks was significantly higher than the first week that observed in all cultivars. Totally, the most resistant cultivar was Sayad and the most susceptible cultivar was Goynok.