Twenty-eight sorghum (Sorghum bicolor) resistant genotypes were selected to study the tolerance as the mechanism of resistance to the greenbug, Schizaphis graminum (Rond.). The genotypes were planted in pots at the EMBRAPA/National Corn and Sorghum Research Center, Sete Lagoas, MG, and individually infested 11-d after planting. Twenty-five greenbug adults/plant were mantained during all the test period. The evaluation was based on the difference of growth rate between infested and non-infested plants. Thirty-five days after infestation the relative growth of infested plants of tolerant genotypes E Redlan A, P 8199 and Tx 2567 was 84.4, 85.8 and 84.0%, respectively. This value was 59.7% for infested plants of susceptible genotype BR 601.
Insecta; host plant resistance; sorghum pest; tolerance
