Managing a destructive, episodic crop disease: A national survey of wheat and barley growers’ experience with Fusarium head blight

Authors: Cowger, Christina; SMITH, JOY - North Carolina State University; BOOS, DENNIS - North Carolina State University; BRADLEY, CARL - University Of Kentucky; RANSOM, JOEL - North Dakota State University; BERGSTROM, GARY - Cornell University

Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/24/2019
Publication Date: 3/1/2020
Citation: Cowger, C., Smith, J., Boos, D., Bradley, C.A., Ransom, J., Bergstrom, G.C. 2020. Managing a destructive, episodic crop disease: A national survey of wheat and barley growers’ experience with Fusarium head blight. Plant Disease. 104:634-648. https://doi.org/10.1094/PDIS-10-18-1803-SR.
DOI: https://doi.org/10.1094/PDIS-10-18-1803-SR

Interpretive Summary: To best manage Fusarium head blight (FHB, or scab) in wheat and barley, producers should use moderately FHB-resistant cultivars, monitor disease risk, and use the most effective fungicides. But adoption of these techniques is uneven in U.S. states that are prone to FHB. In 2014, the U.S. Wheat & Barley Scab Initiative carried out a survey of farmers in 17 states where barley and five types of wheat are grown. The highest percentages of farmers who reported losses due to FHB in the previous five years were in North Dakota, Maryland, Kentucky, and states bordering the Great Lakes. Across all 17 states, =73% of respondents reported no FHB-related losses in the previous five years. Moderately resistant varieties were not widely used in most states and market classes, with the exception of hard red spring wheat. In 15 of the states, most respondents had not applied fungicide for FHB in the previous five years. Of various sources of information on FHB, crop consultants were named by the largest fraction of respondents as an important source or their primary source of information. In most states, about 7% had used a web-based FHB risk forecast, but the percentage was about twice as high in North Dakota. As barriers to adopting management practices, respondents most often named weather or logistics that prevent timely fungicide application; difficulty in identifying the best timing for fungicide application; and the difficulty of using crop rotations that might reduce FHB risk. The results highlight the challenges of managing a crop disease that strikes sporadically, and point to specific areas for improvement.

Technical Abstract: The main techniques for minimizing Fusarium head blight (FHB, or scab) and deoxynivalenol (DON) in wheat and barley are well-established and generally available: moderately FHB-resistant cultivars, monitoring of risk, and timely use of the most effective fungicides. Yet adoption of techniques remains uneven across the FHB-prone portions of the U.S. cereal production area. A national survey was undertaken by the U.S. Wheat & Barley Scab Initiative in 17 states where six market classes of wheat and barley are grown. In 2014, 5,107 useable responses were obtained. The highest percentages reporting losses due to FHB in the previous five years were in North Dakota, Maryland, Kentucky, and states bordering the Great Lakes, but across all states, =73% of respondents reported no FHB-related losses in the previous five years. Adoption of cultivar resistance was uneven by state and market class, and low except among hard red spring wheat growers. In 15 of the states, a majority of respondents had not applied an FHB-targeted fungicide in the previous five years. While primary FHB information source varied by state, crop consultants were considered to be an important source or their primary source of information on risk or management of FHB by the largest percentage of respondents. Use of an FHB risk forecasting web site was about twice as high in North Dakota as the 17-state average of 7%. The most frequently cited barriers to adopting scab management practices were weather or logistics preventing timely fungicide application, difficulty in determining flowering timing for fungicide applications, and the impracticality of FHB-reducing rotations. The results highlight the challenges of managing an episodically damaging crop disease, and point to specific areas for improvement.