Evaluation of foliar fungicide programs in mid-Atlantic winter wheat production systems

Foliar fungicides are commonly used to manage foliar fungal diseases of soft-red winter wheat (SRWW) grown in the mid-Atlantic region, but data on the overall performance and utility of various products and application timings on yield and quality is lacking. Eight replicated experiments were conducted in Delaware and Maryland in 2015 and 2016 to evaluate the effects of 13 fungicide programs, consisting of five commercially-available fungicides applied at flag leaf emergence ([Zadoks growth stage (ZGS) 37], anthesis (ZGS 60), or in two-pass programs with the first application at green-up (ZGS 30) followed by applications at either ZGS 37 or ZGS 60, for utility on naturally occurring foliar diseases on the flag leaf and head, yield, and test weight compared to an untreated check. All fungicide programs reduced disease severity on the flag leaf and resulted in higher test weight and yield compared to the untreated check. Foliar disease on the flag leaf and glume blotch were best managed with ZGS 60 applications. Two-pass programs (ZGS 30 + ZGS 37 or ZGS 30 + ZGS 60) did not result in significantly lower disease severity compared to single applications at ZGS 37 or ZGS 60. Yield was highest within the ZGS 30 + ZGS 60 timing, and while significant, increases were small, ranging from 111 to 198 kg ha−1. Within a given application timing, Priaxor® (ZGS 37), Quilt Xcel® (ZGS 30 + ZGS 37), and Quilt Xcel® (ZGS 30) + Prosaro® (ZGS 60) provided the greatest yields. This information will help guide Integrated Disease Management (IDM) systems in the mid-Atlantic region and assist growers in avoiding unnecessary fungicide applications in SRWW.