Evaluation of insect, disease, and bird damage in grain, silage and forage sorghum hybrids in 2025

Authors: NI, XINZHI; MAILHOT, DANIEL - UNIVERSITY OF GEORGIA; HARRIS-SHULTZ, KAREN; KNOLL, JOSEPH; UYI, OSARIYEKEMWEN - UNIVERSITY OF GEORGIA; TOEWS, MICHAEL - UNIVERSITY OF GEORGIA; DUNN, DUSTIN - UNIVERSITY OF GEORGIA; BUNTIN, G. DAVID - UNIVERSITY OF GEORGIA

Submitted to: Experiment Station Publication
Publication Type: Experiment Station
Publication Acceptance Date: 12/17/2025
Publication Date: 12/17/2025
Citation: Ni, X., Mailhot, D.J., Harris-Shultz, K.R., Knoll, J.E., Uyi, O., Toews, M.D., Dunn, D. and Buntin, G.D. 2025. Evaluation of insect, disease, and bird damage in grain, silage and forage sorghum hybrids in 2025. In: D. J. Mailhot, A. Sutton, J. Arrington, D. Dunn, D. Buntin, X. Ni, and M. Toews (eds.), Georgia 2025 Corn, Sorghum, and Summer Annual Forages Performance Tests. Georgia Agricultural Experiment Stations, Annual Publication 101-17 (December 17, 2025), pp. 56-60. Department of Crop and Soil Sciences, Griffin, GA. 2025

Interpretive Summary: not required.

Technical Abstract: Basic field plot information: The commercial hybrids of grain, silage and forage sorghum were evaluated at Tifton, GA to identify the best performing hybrids. For the silage and forage trials, the plots were planted as 20-foot, four-row plots in a randomized complete block design with three replications, while the grain sorghum trial was planted with a similar design of two-row plots with four replications. In contrast to the previous growing season, the 2025 season had relatively low sorghum aphid infestations in all trials, possibly due to the timing of rainfalls at initial aphid infestations in the experimental plots. While silage and forage sorghum trials were planted on the 24th of April, the grain trial was planted on the 3rd of June. The forage trial was evaluated prior to the harvest on the 20th of June. The silage trial was evaluated on the 7th of August before the harvest. The grain sorghum trial was evaluated on the 1st of August for anthracnose, sorghum aphid (Melanaphis sorghi, also known as sugarcane aphid) infestation, and its damage, and then at maturity on the 18th of September for headworm and bird damage. A total of ten insect pests were observed throughout the 2025 field season, including foliar-feeding fall armyworm, sorghum aphid, corn leaf aphid, and chinch bug at the seedling stage, and panicle/kernel-feeding insects included sorghum headworm complex (corn earworm and sorghum webworm), stink bugs (southern green and brown stink bugs), sorghum midge, and leaf-footed bug after flowering. Bird damage mainly caused by the brown-headed cowbird was only evaluated on grain sorghum. Although the infestations of some insect pests (such as foliar-feeding fall armyworm and chinch bug, and kernel-feeding sorghum midge, stink bugs, and leaf-footed bug) occurred in 2025, they were not included in this report because of minimal damage. For sorghum diseases, only anthracnose infection was evaluated by its severity. Rating scales used for hybrid evaluations: In all trials, sorghum growth stage was assessed using a scale of 0-9 based on the publication S3 by the Kansas-State Research and Extension Service (https://bookstore.ksre.ksu.edu/pubs/MF3234.pdf). The number of sorghum aphids was estimated by averaging the number of aphids on 6 mid-canopy leaves (or the top and bottom green leaves from three randomly sampled plants) per plot. The number of aphids per leaf was estimated using the following scale: 0 = no aphid, 1 = 1-25 aphids, 2 = 26-50, 3 = 51-100, 4 = 101-500, 5 = 501-1000, and 6 = over 1000 aphids. Aphid damage on plants was rated using a 1-9 scale. The scale of 1-9 is described as follows; 1 = no damage, 2 = 1-20%, 3 = 21-30%, 4 = 31-40%, 5 = 41-50%, 6 = 51-60%, 7 = 61-70%, 8 = 71-80%, and 9 = greater than 81% of the leaves are dying, which also included aphid-killed plants. In addition, headworm complex, and bird damage were assessed by the percentage of damaged kernels per panicle only for the grain sorghum trial. Severity of anthracnose infection from all three trials was rated using a 1-5 scale, where 1 = no symptoms, 2 = discolored spot/lesion on leaves but no sporulation, 3 = some sporulation on lower leaves, 4 = moderate sporulation, 5 = heavy sporulation up to the flag leaf. Anthracnose ratings of 1 or 2 are considered resistant. Hybrid ranking criteria: The overall hybrid rankings in 2025 were based on principal component analysis results. Hybrids in a trial were designated as Very Good (VG), Good (G), Fair (F), and Poor (P), respectively. Results from grain, silage and forage sorghum trials: A total of 11 grain sorghum hybrids (Table 1) were evaluated. Aphid and anthracnose damage data were collected on August 1st, headworm and bird damage data were collected on September 18th. Three hybrids were ranked VG in 2025; they are ‘83P38’, ‘BH 5755’ and ‘M66GR32’. Of these hybrids, ‘BH 575