Authors: Shiv Singla 1 and Alyssa K. Betts 1
1. University of Delaware, Newark, DE
Corresponding Author: Alyssa K. Betts, akoehler@udel.edu
Presenting Author: Shiv Singla
Abstract
Malting barley is a specialized variety of barley (Hordeum vulgare) expanding as an important crop in southern Delaware following continued growth of the craft brewing industry and the opening of a local malting facility. Malting and brewing industries require grain to meet strict quality standards that can be reduced due to disease. One of the most important diseases impacting malting barley is Fusarium head blight (FHB) primarily caused by the fungus Fusarium graminearum. FHB results in infected grain with deteriorated quality. Grain quality is further impacted by the production of mycotoxins like deoxynivalenol (DON), which may result in dockage or total rejection of harvested grain when present above threshold levels. Management of FHB relies on partial resistance, which is limited in current malting varieties, and the application of properly timed fungicides. As new varieties and fungicide products enter the market, testing is needed to evaluate their efficacy for management of FHB. Violetta was the most widespread variety planted in DE, but growers have been shifting to a newly released variety, Avalon. In this project, these two varieties were assessed in combination with four fungicide treatments, Prosaro®, Prosaro Pro, Miravis® Ace, and Sphaerex™ and two non-treated controls (one inoculated, one non-inoculated) to evaluate response of FHB. With the exception of plots for the non-treated non-inoculated control treatment, all plots were inoculated with colonized corn spawn. Plots were evaluated for FHB incidence, FHB severity, Fusarium damaged kernels (FDKs), yield, and for DON. Comparing the non-treated inoculated controls of both varieties, the %FDK and DON levels in Violetta were significantly higher than in Avalon. For Avalon, plots treated with Prosaro, Prosaro Pro, and Miravis Ace had significantly lower FHB incidence than the non-treated inoculated plots. Additionally, for Avalon, DON was significantly lower in plots treated with Prosaro Pro and Miravis Ace-compared to the non-treated inoculated plots. In Violetta, plots treated with Miravis Ace had significantly reduced FDK, and plots treated with Prosaro Pro, Miravis Ace, and Sphaerex had significantly reduced DON levels compared to the non-treated inoculated plots. Results indicate that reduced FHB and DON levels in Avalon compared to Violetta support the transition to this variety. Additionally, the use of Prosaro Pro and Miravis Ace applied at anthesis can improve crop quality by reducing FHB and DON levels for both varieties. This study provides practical insights for barley growers in Delaware that guide informed integrated approaches to manage FHB.