Young-Ki said proper cultural practices may not always provide acceptable control of sheath blight, the most common and most economically important disease in Texas rice production.

“Disease pressure can be alleviated to a certain level by integrating management practices including crop rotation and use of resistant varieties.” But that may not be enough to “guarantee yield protection from disease outbreaks under hot and humid conditions,” he said.

Fungicide application may be necessary to manage sheath blight in both the main and the ratoon crop, Young-Ki said.

He said a fungicide program study evaluated 12 treatments on Cocodrie rice. “Sheath blight was promoted with additional inoculation of Rhizoctonia solani.”

Results showed a tank mixture of strobilurin and trizole fungicide as the best control option in the main crop and with significantly less disease severity in the ratoon crop. Yield also increased.

“Disease severity in the main crop directly affected rice stand densities and yields in the ratoon crop,” Young-Ki said. “Keeping sheath blight at a low level on the main crop by appropriate use of fungicides is critical to successful ratoon crop production.”