Field evaluation of fourteen soybean genotypes for resistance to whitefly (Homoptera: Aleyrodidae) infestations

Fourteen soybean genotypes in maturity groups VII and VIII were evaluated for resistance to Bemisia argentifolii Bellows and Perring and Trialeurodes abutilonea (Haldeman) at 2 field locations in Tift County, Georgia in 1993 and 1994. Significant differences in mean whitefly densities were observed among the 14 soybean genotypes. 'Perrin', 'Cook', and 'N88- 91' had significantly lower mean numbers of whiteflies than many of the other entries during both seasons at both test sites. Fewer B. argentifolii eggs were oviposited on these 3 soybean entries compared with the susceptible varieties 'Braxton' and 'Cobb', demonstrating an antixenosis plant resistance response. The soybean breeding lines 'N89-1' and 'F90-724' also were highly preferred hosts for B. argentifolii oviposition. Much lower T. abutilonea population densities were observed; however, the same general trends in host preference were observed. More than 70% of the mean whitefly population was composed of B. argentifolii in 1993 and 95% was B. argentifolii in 1994. Sticky traps were used to monitor the presence of both species of adults in the field and to determine when peak adult populations occurred. Trap captures were low in June of both years and rose steadily until whitefly densities peaked in mid-to late September