Evaluation of foliar fungicide programs in mid-Atlantic soft-red winter wheat
Date
2017
Authors
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Publisher
University of Delaware
Abstract
Foliar fungicides are commonly used by growers to manage fungal diseases of the foliage and head in mid-Atlantic soft-red winter wheat (SRWW). Fungicide applications between flag leaf emergence (Feekes growth stage [FGS] 8) and heading (FGS 10.5) have been considered the standard application timing. However, there has been a shift towards two-pass programs and late applications at beginning anthesis (FGS 10.5.1), but these programs have not been thoroughly evaluated for foliar disease control, test weight, yield, and economic benefit in the mid-Atlantic region. Experiments were conducted in Delaware, Maryland, Pennsylvania, and Virginia in 2015 and 2016 to evaluate commercially available fungicides with applications at FGS 8, FGS 10.5.1, and programs with an early application at green-up (FGS 5) followed by applications at either FGS 8 or FGS 10.5.1. All fungicide programs reduced foliar disease severity on the flag leaf and resulted in higher test weight and yield compared to the untreated check. Two-pass programs (FGS 5 + FGS 8 or FGS 5 + FGS 10.5.1) did not result in significantly lower disease severity compared to single applications at FGS 8 or FGS 10.5.1. Grain yield was highest within the FGS 5 + FGS 10.5.1 timing, and while significant, increases were small when compared to other tested application timings. The probability of profitability ranged from 0.49 to 0.56 for programs with a single application at FGS 8 compared to 0.53 for a single application of Prosaro® at FGS 10.5.1, indicating similar profitability between program timings. Two-pass programs with an early application at FGS 5 followed by FGS 8 or FGS 10.5.1 resulted in a similar probability of profitability compared to single application programs, ranging from 0.48-0.57 (FGS 5 FB FGS 8) and 0.52-0.59 (FGS 5 FB FGS 10.5.1). These findings lay the groundwork for larger scale future fungicide studies, which could be used to make a fungicide application decision-making tool for managing foliar disease in mid-Atlantic SRWW production.
Description
Keywords
Biological sciences, Fungicides, Profitability, Wheat