Economic Evaluation of Soybean Fungicide Seed Treatments

Received for publication April 1, 2005. The effects of fungicide seed treatments on seeding rate, location, simulated rainfall at emergence, time of planting, and seed quality were analyzed for soybean [Glycine max (L.) Merr.] in this study. Variation in plant emergence allowed estimation of economically optimal seeding rates and partial returns (PR = Gross revenue - Seed cost) across seed treatment options. Study results proved a single seed treatment to be superior across most study conditions. In fact, a comparison of optimally treated to untreated seed revealed that a seemingly insignificant input in terms of cost (<$8.65 ha^-1) enhanced profitability by an average of $43.71 ha-1 in this study. Using high rather than low quality treated seed increased producer returns by an average of $64.27 ha-1. Seeding rate recommendations need to be viewed with the precaution that added seed may be low cost insurance against lesser-than-expected survival rates. For the cultivar Hutcheson (MG V), planting in May compared with April and June provided better yields using less seed on average. Finally, as the planting season progressed, replanting plant population density thresholds decreased.