(2nd Place) The role of timing of hilling and its impact on soybean gall midge

Soybean gall midge (Resseliella maxima Gagné, SGM) is an emerging pest that can cause significant yield loss in soybean, particularly along field edges. Despite being discovered in 2019, SGM has been detected across five Midwestern states in 155 counties. SGM infestation primarily depends on fissures near the base of the plant that forms during the V2 growth stage. Hilling, a cultural approach of covering fissures with soil, has been found to reduce SGM infestation by limiting adult access to stems. To better understand this management practice, hilling was performed at different times (V2, V5, R2) in soybean growth stages in 2022. The study was conducted as a randomized complete block design with four replications. Each replication had the three hilling timings as treatments and an un-hilled control (UN). Findings demonstrated that the earliest hilling at the date (V2 stage) had the lowest SGM abundance, lowest plant injury, and greatest yields. A second year of this study will be conducted in the 2023 growing season. The timing of hilling helps us understand the window when soybean needs to be protected to reduce yield losses caused by SGM.