Outbreaks of leaf blast have occurred in commercial rice fields in Jackson, Wharton and Victoria Counties, Texas. The affected varieties were Presidio (long grain) and Jupiter (medium grain). Jupiter appeared to be more severe in leaf blast than Presidio. The outbreaks of leaf blast apparently resulted from the historical record of rainfalls that occurred recently in Texas. Tropical Storm Bill has brought additional rainy days that are favorable for the development of rice blast.
This year’s leaf blast was detected approximately one week earlier than previous years. Outbreaks of rice blast caused considerable damage to Texas rice in 2012, 2013 and 2014. This is the fourth year in a row that rice blast has attached Texas rice. In Louisiana, leaf blast also has been reported on Jupiter and CL151 in 2015.
Given the favorable weather conditions and early detection of leaf blast, rice blast poses a serious threat to Texas rice production this year. Below are the tips to manage rice blast:
- Scout fields for the presence of rice blast at least weekly until the heading stage. Timely detection of rice blast is critical.
- Maintaining a 4-to-6-inch continuous flood is an effective management practice to reduce the damage caused by this disease.
- Timely applications of fungicides are important. If a single application is made, it should be applied at the heading stage (50% to 70% heads emerging from the boot).
- If two applications are made because of severe disease pressure, the first application should be made at boot (2-4 inch panicle), followed by the second application at heading.
- Trifloxystrobin-containing fungicides (Stratego, 16-19 oz/A; and Gem, 3.1-4.7 oz/A) are most effective. Azoxystrobin-containing fungicides (Quadris, 12-15 oz/A; Quilt, 28‐34 oz/A; and Quilt Xcel, 21‐28 oz/A) also are effective.
- For more information about rice blast disease and its management, please visit the 2014 Texas Rice Production Guidelines.
If you suspect rice blast in your fields and need more information about its management, you can contact Dr. Shane Zhou at xzhou@aesrg.tamu.edu or (409) 752 2741 ext. 2210 or Mr. J. J. Schmidt at schmidtcropcare@gmail.com or (979) 758 4800.
