Scout now to manage sheath blight in rice
July 17, 2023
By Sarah Cato
U of A System Division of Agriculture
Fast Facts:
- Arkansas rice moving into reproductive stages, becoming susceptible to sheath blight
- Recent and upcoming rains could cause disease to progress more quickly
- Specialists recommend scouting, applying fungicide only when necessary
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(Newsrooms: Download photo of sheath blight infected rice)
LITTLE ROCK — As Arkansas rice fields move into reproductive stages, specialists with the University of Arkansas System Division of Agriculture are advising producers to scout for sheath blight, especially as frequent rain can accelerate its growth.
Sheath blight, a disease caused by the fungus Rhizoctonia solani, is prevalent in Arkansas rice fields. It causes long, oval, purple-bordered lesions and bands of dying tissue in the leaf blades. Symptoms are typically seen as rice moves into reproductive stages. Jarrod Hardke, extension rice agronomist for the Division of Agriculture, said scouting and potential fungicide applications are recommended to avoid yield loss.
“While sheath blight presence has been increasing, it is only just starting to take off up in the canopy in some fields,” Hardke said. “Rains this week and over the weekend may aggravate it and make it more aggressive, so be on the lookout.”
Hardke noted that some fields may be out of the danger zone for sheath blight. “There are some fields making it to heading with sheath blight still low, meaning we’ve outrun yield loss,” he said.
Camila Nicolli, extension plant pathologist for the Division of Agriculture, said scouting is key to mitigating impact.
“One of the primary reasons scouting for disease is crucial is that early detection of symptoms allows for quick action. Especially for sheath blight, that requires opening the canopy to check,” Nicolli said. “The goal is to identify sheath blight at its initial stages before it begins to progress. Then we can monitor progress to determine if treatment is warranted.”
Scouting rice for sheath blight involves checking in a zigzag pattern, stopping every 50 steps and inspecting 3-foot-long sections for symptoms. If symptoms are present, the stop is a “positive stop.” Division of Agriculture specialists recommend fungicide applications at 35 to 50 percent positive stops, depending on which variety of rice is planted.
Find recommendations for sheath blight management in the 2023 Rice Management Guide. Read more about current Arkansas rice conditions in the latest Arkansas Rice Update.
To learn about extension programs in Arkansas, contact your local Cooperative Extension Service agent or visit www.uaex.uada.edu. Follow us on Twitter and Instagram at @AR_Extension. To learn more about Division of Agriculture research, visit the Arkansas Agricultural Experiment Station website: https://aaes.uada.edu/. Follow on Twitter at @ArkAgResearch. To learn more about the Division of Agriculture, visit https://uada.edu/. Follow us on Twitter at @AgInArk.
About the Division of Agriculture
The University of Arkansas System Division of Agriculture’s mission is to strengthen agriculture, communities, and families by connecting trusted research to the adoption of best practices. Through the Agricultural Experiment Station and the Cooperative Extension Service, the Division of Agriculture conducts research and extension work within the nation’s historic land grant education system.
The Division of Agriculture is one of 20 entities within the University of Arkansas System. It has offices in all 75 counties in Arkansas and faculty on five system campuses.
The University of Arkansas System Division of Agriculture offers all its Extension and Research programs to all eligible persons without regard to race, color, sex, gender identity, sexual orientation, national origin, religion, age, disability, marital or veteran status, genetic information, or any other legally protected status, and is an Affirmative Action/Equal Opportunity Employer.
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Media Contact:
Sarah Cato
scato@uada.edu
870-815-9035