Tolerance Of Sorghum Hybrids Resistant To Yellow Aphid, Melanaphis Sacchari(1) (Zehntner), In Mexico

Melanaphis sacchari (Zehntner), yellow aphid, is one of the main pests of sorghum (Sorghum bicolor (L.) Moench) in Mexico. It causes direct damage as a sucking insect and indirect damage by production of honeydew on which sooty mold develops, which interrupts the normal process of photosynthesis in sorghum plants and contaminates grain. The experiment was established at Celaya, Guanajuato, Mexico, during spring-summer 2016. In total, 80 commercial genotypes of sorghum were evaluated. Resistance to the yellow aphid was assessed under field conditions; six planting dates were used at 15-day intervals from 15 April to 30 June. Degree of yellow aphid infestation by genotype was evaluated every 10 days after emergence; five plants were chosen at random for counting aphids on the lower and upper sides of leaves. In addition, damage was scored and grain yield estimated. The study identified sorghum genotypes with resistance to yellow sorghum aphid in Mexico. Use of the materials by producers controls a higher management threshold by decreasing the number of insecticide applications required for control.