Comparison of a Tolerant and a Susceptible Maize Inbred Under Artificial Infestations of Diabrotica virgifera virgifera 1 : Yield and Adult Emergence

Abstract

Uniform artificial infestations with eggs of Diabrotica virgifera virgifera LeConte produced the same root damage ratings with both a rootworm-tolerant inbred (SD 10) and a rootworm-susceptible inbred (A 632). Yields of SD 10, however, generally remained the same under the different levels of rootworm infestation, whereas Yields of A 632 were significantly reduced at every level beyond 100 eggs/30.5 cm of row. Clearly, under rootworm infestation, the tolerant inbred had a yield advantage over the susceptible inbred. The same number of adults emerged from the inbred with the smaller root system (A 632) as from the inbred with the larger root system (SD 10). These results indicate that under rootworm infestation, tolerant maizes with large root systems would have yield advantages over maizes with small root systems. Moreover, the use of tolerant maizes would probably not lead to an increase in adult numbers.