Karen R. Harris-Shultz, Xinzhi Ni, William F. Anderson, Joseph E. Knoll
Journal of Entomological Science 50 (1), 14-27, (1 January 2015) https://doi.org/10.18474/0749-8004-50.1.14
KEYWORDS: Sorghum bicolor, Spodoptera frugiperda, maize, infestation
The fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), is an economically important pest of sorghum, Sorghum bicolor (L.) Moench. However, resistance to fall armyworm in sweet sorghum has not been extensively studied. A collection of primarily sweet sorghum accessions were evaluated in the field for natural fall armyworm infestation. Fall armyworm damage ratings ranged from 1.88 ± 0.35 to 4.75 ± 0.37, suggesting that a range of response to fall armyworm feeding exists in this collection. Based on the results of field data from two planting dates, accessions with the highest and lowest fall armyworm damage ratings were selected for greenhouse evaluations. At 7 d after infestation, the sorghum accessions, excluding BTx623 and Plant Introduction (PI) 147573, had significantly higher fall armyworm damage than resistant control MP708. Furthermore, at 7 d after the infestation, genotype PI 147573 was the most resistant; whereas, genotypes 13, 22, ‘GT-IR8′, and ‘GT-IR6′ were the most susceptible to fall armyworm feeding. For the damage ratings at 14 d after the infestation, sorghum Entry 13 had significantly higher fall armyworm damage than GT-IR7 and PI 17548. At 14 d after infestation, all nine sorghum accessions were as resistant as the MP708 resistant control and had significantly less damage than the susceptible control AB24E. These data suggest that the sorghum lines at 14 d have induced resistance in the growing whorl.