Meta-analysis of yield response of foliar fungicide-treated hybrid corn in the United States and Ontario, Canada

Background: Foliar fungicide applications to corn (Zea mays) occur at one or more application timings ranging from early vegetative growth stages to mid-reproductive stages. Previous studies indicated that fungicide applications are profitable under high disease pressure when applied during the tasseling to silking growth stages. Few comprehensive studies in corn have examined the impact of fungicide applications at an early vegetative growth stage (V6) compared to late application timings (VT) for yield response and return on fungicide investment (ROI) across multiple locations. Objective: Compare yield response of fungicide application timing across multiple fungicide classes and calculate the probability of positive ROI. Data sources: Data were collected specifically for this analysis using a uniform protocol conducted in 13 states in the United States and one province in Canada from 2014 - 2015. Synthesis methods: Data were subjected to a primary mixed-model analysis of variance. Su...