Plant Resistance in Sorghums to the Sugarcane Aphid (Hemiptera: Aphididae)

Abstract  Ten sorghum, Sorghum bicolor (L.) Moench, lines near or in commercial release were evaluated with the intent of identifying the phenotypic expression of host-plant resistance to the sugarcane aphid Melanaphis sacchari (Zehnter) (Hemiptera: Aphididae). Two of the 10 entries (OL2042 and SP7715) expressed a high degree of resistance to the sugarcane aphid, with damage ratings 4.0 and were statistically lower than the susceptible check Tx7000. Chlorophyll loss and damage ratings exhibited a linear relationship (R2 = 0.87), followed by a slight improvement (R2 = 0.89) in the regression models when the difference in plant height was added as a second independent variable. The relationship helps e...