An investigation on resistance of 19 common bean genotypes to two-spotted spider mite, Tetranychus urticae (Acari: Tetranychidae), in three regions of Iran

Two-spotted spider mite, Tetranychus urticae Koch, is one of the important pests of common bean that causes serious damage to agricultural crops. In this study, nineteen common bean genotypes were evaluated for resistance to the two-spotted spider mite. The trial was carried out at field conditions of Karaj, Brojerd and Khomein. One week after mite infestation, the total number of female and eggs were counted for two times. Also, mite damage feeding was evaluated with a 1-6 scale. Khomein had the fewest infested mean and relative resistance of many genotypes was failed in comparison to susceptible standard genotype (Akhtar) at Khomein. So they should be eliminated in alternative breeding programs. Nevertheless, only Ks41128 that had good relative resistance at other regions had the most relative resistance at Khomein. Subsequently, we propose Ks41128 as the most resistance and also the most stable genotypes.