Submitted to: Entomological Society of America Regional Meetings
Publication Type: Abstract Only
Publication Acceptance Date: 11/15/2010
Publication Date: N/A
Interpretive Summary: not required
Technical Abstract: Sweet sorghum [Sorghum bicolor (L.) Moench] is one of the favorable biofuel feedstocks for ethanol production. Fall armyworm [Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae)] is one of the most serious foliar-feeding insect pests in sorghum production in the southeastern US states. Severe whorl injury of fall armyworms results in significant reduction of sweet sorghum biomass accumulation. Breeding for fall armyworm-resistant sweet sorghum hybrids with high yield potential is one of the long-term goals of our research team. In the present study, 116 sweet sorghum inbred lines were evaluated for fall armyworm resistance with natural fall armyworm infestation. The experiment utilized a randomized complete block design with two replications of double-row plots. The experiment was repeated with two planting dates in 2009. In addition to fall armyworm resistance, anthracnose resistance, maturity, plant height, and BRIX value were also evaluated. Fall armyworm injury was assessed using a visual rating scale (1-9; 1 = no injury, while 9 = complete defoliation) on each row of the experimental plots; Anthracnose resistance was rated as 1-5 (1 = most resistant); Maturity was rated as 0-5 (0 = no flowering heads, 5 = fully matured heads); Plant Height was measured as meters; and BRIX values were assessed 90 d after each planting, and high BRIX value denoted high sugar content. We identified 60 entries as a subset to be further examined. Among these selected inbreds, entries 62, 99 and 115 are the best with the low fall armyworm injury ratings (< 3) and favorable values of the other four parameters. In contrast, entries 3, 4, and 78 were the worst with the highest fall armyworm injury ratings (> 4.5) and less desirable values of other parameters. The identification of the four fall armyworm-resistant sweet sorghum inbred lines with favorable agronomic traits is important to develop new sweet sorghum hybrids with reduced or no insecticide applications, and improved biomass production in our region.