Effects of Strobilurin Containing Fungicides on Soybean Grain Yield and Disease Control.

Strobilurin containing (e.g., Priaxor, Trivapro, Stratego, Approach Prima) fungicide application can be a vital and necessary practice in modern soybean production. Strobilurins effectively control many fungal pathogens by inhibiting mitochondrial respiration in fungal cells. In addition, these compounds have been shown to decrease ethylene biosynthesis, reduce oxidative stress in plants and decrease photosynthetic losses by inhibiting mitochondrial respiration. Yield response to fungicide application can be highly variable as a result of varying disease pressure, and can be affected by environmental and management factors that influence soybean yield potential. The focus of this research was to determine the variance in soybean yield response to fungicide applications of different strobilurin active ingredients and the effectiveness of disease control in two central and southern Illinois locations. Soybeans were planted in both locations at a population of 128,000 plants per acre, and all strobilurin applications were made during the R3 stage. Assessments were taken on the effectiveness of disease control (Frogeye leaf spot, Septoria brown spot), and yield impacts. Similarly, visual valuations of crop response and soybean stay green were made. The conclusions made based upon this research could provide growers with valuable information on the impacts of strobilurin containing fungicides on soybean grain yield.