High Moisture Wheat Harvest Effects on Grain Quality and Dioxynivalenol (DON) Levels.

Soft Red Winter Wheat (Triticum aestivum L.) typically flowers from mid to late May in Ohio. High rainfall along with warm temperatures provide ideal conditions for Fusarium Head Blight (FHB) to infect flowering spiklets and spread through the wheat spike. As the fungus spreads, neighboring spiklets and subsequent seeds are infected, resulting in scabby and damaged kernels. FHB also produces a mycotoxin known as deoxynivalenol (DON) which can cause vomiting in humans and animals. Flour mills set limitations on the amount of scab, Fusarium-damaged kernels (FDK), and DON a grain sample can contain. Samples over the allowed limits are penalized or rejected depending on the severity. The objective of this research was to evaluate the effects of harvesting the grain early and drying it, potentially reducing fungal growth and subsequent seed damage, compared to the alternative of allowing the grain dry naturally in the field. Three varieties were planted at the Western Agricultural Research Farm in South Charleston, Ohio in a randomized complete block design with two harvest treatments of early (19% moisture) and late (13% moisture) and four replicates. The three varieties had a range of susceptibility to FHB: Hopewelll – susceptible, Bromfield – moderately susceptible, and Malabar – moderately resistant. Plants were inoculated at 50% anthesis with macroconidia to ensure high FHB pressure. Grain was harvested with a plot combine recording moisture, yield, and test weight, and grain samples were collected and dried to 13% moisture. Representative grain samples were used to quantify scab, FDK, and DON. Results will be presented.