Can Fusarium Head Blight Vomitoxin Levels Be Reduced with Agronomic Practices?

Can Fusarium Head Blight Vomitoxin Levels Be Reduced with Agronomic Practices? Carrie Knott and Carl Bradley Each year, vomitoxin levels in soft red winter wheat are a major concern for the wheat industry including producers, millers, and bakers. It is well known that agronomic practices are very important to minimizing vomitoxin (deoxynivalenol) levels. Current practices include using moderately resistant wheat varieties and applying a fungicide at beginning flowering (Feekes 10.5.1). However, it is unclear whether additional agronomic practices can be implemented that would reduce vomitoxin accumulation in Kentucky. One agronomic practice that may reduce vomitoxin levels is harvesting wheat grain with moisture content greater than 13%. Recently the Ohio]based milling company, Mennel Milling Company, announced that they would begin accepting wheat at 15% grain moisture content without a discounted price. This is based upon their observations that vomitoxin levels are typically less in grain they accept at 15% moisture and then dry at their facilities than grain that dried in the field to 13% moisture. Additionally, there are some producers that are harvesting at even greater moisture (20]22%). They have observed that grain yields are greater and vomitoxin levels are lesser when harvested at high moisture (even when adjusted to 13.5%) than grain harvested at lower moistures (13]15%). Another agronomic practice that has been reported to potentially reduce vomitoxin levels is in]furrow phosphorus at planting. There are numerous reports of in]furrow and at]planting phosphorus applications increasing grain yield and winter survival in areas with low soil phosphorus levels. Much research in the United States has focused on grain yield increases in low soil test P levels. However, research in Virginia found wheat forage yield was greater when seed]banded P fertilizer was applied to high soil test P soils. Additionally, in one study the addition of phosphorus at planting, on soils with high soil test P levels, resulted in more plants per ft2, more tillers at Feekes 3 and Feekes 5 growth stages, and more heads at flowering. More recently, Canadian researchers have indicated that in]furrow phosphorus applications also increase uniformity of heading on low phosphorus soils, which could reduce vomitoxin levels by protecting a higher percentage of heads with the Feekes 10.5.1 fungicide. This project would investigate the effect of vomitoxin levels when wheat grain is harvested at different grain moisture contents. For wheat harvested above 13%, grain will be dried to 13% at 165‹F in grain columns at UKREC in Princeton. We also propose to investigate the effect of phosphorus application at planting on the uniformity of wheat head emergence and flowering. To complete this project we are requesting $35,750. Funds will be used to support 50% of a Ph.D. student, supplies to complete the project, and travel funds for the student to travel to Princeton to complete the proposed research.