Impact of Fungicides on Dual-Purpose and Brown Midrib Zea mays Hybrids Used for Silage in Wisconsin

Abstract

Decisions about hybrid choice and fungicide application when growing corn ( Zea mays L.) for silage are important considerations to maximize sustainable production. The objective of this research was to evaluate how brown midrib hybrids compare with dual-purpose hybrids and how fungicides interact with these two classes of corn hybrids. To explore this, field research trials were conducted in Arlington, Wisconsin, in 2020 and 2021. In both years, the trials were arranged in a randomized complete block design and included one brown midrib hybrid, one dual-purpose hybrid, and seven fungicide application regimes. In-field disease ratings were made for tar spot (caused by Phyllachora maydis), ear rot, and stalk rot (caused by Gibberella zeae). Harvested silage was analyzed for yield, quality, and deoxynivalenol (DON) concentration. The selection of hybrid significantly ( P < 0.01) influenced the silage quality parameters, such as starch and total tract neutral detergent fiber digestibility, a measure of fiber digested throughout the tract of a cow. Fungicide use influenced dry matter yield ( P < 0.05), tar spot severity ( P < 0.01), and DON concentration ( P = 0.05). Our findings suggest that using appropriate fungicides improves yield and reduces disease severity and DON contamination. Better quality silage could be obtained from brown midrib hybrids at the expense of yield. Therefore, Wisconsin farmers are encouraged to primarily utilize a dual-purpose class of corn hybrids to ensure optimal milk production and secondarily apply fungicides to reduce DON levels in corn chopped for silage.