The Effect Of Mid Season Foliar Fungicide And Insecticide Applied Alone Or In Combination On Soybean Yield In Ohio

Ohio soybean farmers are very concerned about disease and insect pressure during the midseason that may impact yield. The impact of mid-season management for foliar diseases and insect feeding on grain yield was studied in a series of field experiments. The first objective was to evaluate the effect of mid-season foliar fungicide and insecticide application on soybean yield, applied alone or in combination. A trial was established at 12 on-farm field site-years in Ohio during 2015 and 2016 in a randomized complete block design with four replications per treatment. Fungicide and insecticide treatments included: 1) nontreated control, 2) fungicide alone, 3) insecticide alone, 4) fungicide plus insecticide (tank-mixed), 5) fungicide and insecticide (separate tank), 6) fungicide plus crop oil, 7) insecticide plus crop oil, 8) fungicide, insecticide plus crop oil (tank-mixed). All treatments were applied at R3 growth stage (initial pod development), and data on the percent leaf area affected by foliar diseases and insect defoliation was collected. There was no significant yield response associated with insecticide application due to low insect pressure and low insect defoliation levels at the time of insecticide application at all 12 site-years. However, at the end of the growing season, the number of bean leaf beetles (2-22) and pod injury caused by their feeding (4.1-37%) were high at 4 out of 12 site-years. Fungicide application alone had significantly (P