We grow rice in water with plenty of heat and humidity. Essentially, it’s a potential disease paradise. Fortunately, breeding and cultivar selection, along with improving agronomics, have taken us a long way in the fight against disease.
While planting is complete, our ability to maximize yields with lower plant stands creates an environment less favorable to disease. Continue to focus in the future on achieving optimal stand densities rather than just a planting rate. The question should be “what seeding rate do I need to achieve my optimal stand?”
Increased nitrogen (N) use efficiency through the use of nitrogen stabilizers, improved water management, and avoidance of excess N further limit excessive plant growth that promotes disease development. The question should be “what N rate and application strategy produces the most economic yield while avoiding excessive N?”
Improved potassium (K) fertility has further limited disease issues, as optimal K fertilization is critical to plant disease defense. The online potash rate calculator can help fine-tune K rates beyond standard K recommendations. The question should be “what K rate is needed to maximize plant health and yield?”
Sheath blight is the one disease in rice we can truly scout and treat based on thresholds. Optimal plant stand density, N rates, and K rates minimize the development of this disease. The question should be “does my sheath blight severity and incidence justify the cost of fungicide and application?”
Neck and panicle blast, Cercospora, and the smuts all must be controlled with preventative management because once you see it, it’s too late. The question should be “do I have a susceptible cultivar, history of the disease, and conditions that are favorable for the disease?”
The answers to these questions are “it all depends!” Seeding rate choices will vary by farm and field based on soil and conditions. Nitrogen and K management will vary similarly. For sheath blight, utilize the recommended thresholds. For the other diseases, rely on your knowledge of fields and cultivars along with the amount of risk you can accept.
In 2026, the focus is on saving money where we can, and disease management will be no different. Fungicides have become more economical in recent years, but any expense needs to at least pay for itself. Consider growing conditions, thresholds, and risk when determining the need for a fungicide application. The better we’re able to manage the crop, the less disease pressure, but prepare to defend yourself. ∆
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