By Yeshi Wasmish, Extension rice pathologist; and Jarrod Hardke, Extension rice agronomist
It is a little unusual to see blast in the first week of June (6/6). Leaf blast was detected in Lonoke County last week and also this week (6/11) in Randolph County. Both counties reported blast on the new medium grain rice, Titan. Read here on the elaborated leaf blast report of last week.
Titan was rated (MS) to blast since its release. It has been less susceptible than Jupiter to blast in our greenhouse tests and under field conditions. However, since it has genetic relationship with Jupiter, we need to continue scouting for blast. Remember, fungicide application may not be needed for leaf blast unless it is burning down the leaves. Leaf blast is often suppressed by increasing flood and maintaining a depth of at least 4 inches. The hot conditions may make keeping deep flood difficult. However, water does the required job to suppress leaf blast in rice. The spores of blast fungus are light in weight and can be blown by wind to several miles. In fields with a history of blast planted with susceptible varieties, timely and two times protective fungicide applications are recommended to suppress neck and panicle blast. Late season neck and panicle blast are the most devastating forms causing near 100% grain yield loss. Distinctive lesions from leaf blast are diamond -shaped with ashy centers as in Figure 1.
Acknowledgement: We thank the University of Arkansas Division of Agriculture Cooperative Extension Service county agents and consultants for timely field info.