Fusarium
graminearum is the causal agent of the Fusarium
head blight (FHB), an important disease of small grains that significantly
reduces yield and quality of grains. In addition, it can cause the accumulation
of the mycotoxin deoxynivalenol (DON) impacting both human and animal health. In
2021, 1.69% loss in wheat production were reported in the North Central States
a value of $109.8 million (458,000 metric tons). Currently disease management
recommendations are limited for organic wheat production on Organic Materials
Review Institute (OMRI) approved products. The objective of this study was to
evaluate the effects of two winter wheat organic cultivars, Kaskaskia - FHB susceptible,
and Harpoon - FHB resistant, and four OMRI products for FHB integrated
management in Indiana. Field trials were established in 2020 and 2021. The
experiments had a split-plot design with four replications, cultivars were the
main plot and fungicide treatments as subplots. The four OMRI products evaluated
included Reynoutria sachalinensis 12% (0.9 L ha⁻¹); Bacillus pumilus
QST 2808 (2.3 L ha⁻¹), Streptomyces lydicus WYEC 108 (0.6 L ha⁻¹), and
copper hydroxide (1.7 kg ha⁻¹), and compared to a conventional fungicide
(prothioconazole + tebuconazole, 0.8 kg ha⁻¹) and a nontreated control. All
products were applied at Feekes 10.5.1. All plots were inoculated with a spore
suspension of F. graminearum 24 hours after treatment. Disease
ratings were assessed at Feekes growth stages 11.2 and data combined across
years. No differences were detected in both cultivars. There
were no significant interactions between cultivar and treatment, therefore main
effects were compared. No differences between products and nontreated were detected
for FHB incidence (P = 0.4587). FHB severity (P = 0.0143) was only
significantly reduced by copper hydroxide over nontreated control. In addition,
FHB index (P = 0.0220) was reduced by copper hydroxide and
prothioconazole + tebuconazole. No significant differences between treatments and
nontreated control were observed for yield (P = 0.9197) and DON
concentrations (P = 0.4172). These preliminary results presented provide
evidence that copper hydroxide might be an option for FHB management in organic
winter wheat systems. Future work should continue to evaluate OMRI
approved products to determine their efficacy and to provide information about
disease management tools for organic farmers in Midwest.