Screening technique to evaluate soybean resistance to whitefly, Bemisia tabaci (Gennadius) under screen-house conditions

In this study efforts were made to develop a screen-house-based screening technique against whitefly, Bemisia tabaci. Seven vegetative growth stages of soybean were selected and, in each stage, different whitefly adult densities (0, 10, 25, 50, 75, 100, 125 and 150) were released per plant under no-choice conditions and leaf damage grades were recorded at 3 days intervals for up to 24 days. The responses of eight soybean genotypes against whitefly were evaluated in a multiple-choice test conducted under screen-house conditions. At the V₃ growth stage of genotypes, 125 whitefly adults per plant were released and recorded the damage injury grades. The genotypes were categorized into various groups using the whitefly resistance index (WRI). The genotypes SL 1028 and SL 1074 were categorized as moderately resistant, PS 1347 and PS 1572 as moderately susceptible and SL 1113, SL 958 and SL 688 as susceptible and genotype DS 3105 as highly susceptible. All the genotypes, except SL 1028 and SL 1074 have scored the leaf injury grade V at the end of the study period (6 weeks).