Evalution of Split Applications of Folicur and JAU 6476 for the Control of Scab and DON on Barley.

Fusarium Head blight (FHB) has reduced the quality of barley grown in the Midwest for the last decade due to fungus infected and discolored kernels, and most importantly the presence of the toxin, deoxynivalenol (DON). Individual cultural and chemical control measures have reduced disease, but not the level of control needed by the malting barley industry. The reduced control with fungicides is likely due to the long period during which the barley plant is susceptible to the infection. Field experiments were undertaken to determine the effect of multiple applications of fungicides at different rates. Fungicides tested were Folicur (Bayer CropScience), and JAU6476 (Bayer CropScience experimental) currently labeled as Prothioconazole (Proline 480 SC). The 6-rowed cultivar Robust and 2-rowed cultivar Conlon were used as they are commonly grown in the Midwest and they differ in the amount of disease and DON accumulation they experience under the same environmental and inoculum conditions. None of the Folicur treatments on Robust barley reduced FHB or DON significantly compared to the untreated control. However, all JAU6476 treatments significantly reduced FHB compared to the control. An application of JAU6476 at 85.5 ml or 171 ml/ha when applied at Feekes 10.5 growth stage and again seven days later, reduced DON significantly compared to the untreated control. Yield was not increased significantly by any of the fungicides treatments compared to the control although numerically all yields were greater in treated plots compared to untreated. In Conlon, Folicur and JAU6476 treatments reduced FHB significantly compared to the untreated control. DON was not affected significantly by fungicide treatments but Conlon is a low DON accumulator compared to Robust with the unsprayed control having 2.7 µg/g of DON compared to untreated Robust with 6.7 µg/g of DON. In Conlon, yield was not influenced by any of the fungicide treatments.