Poster Session: Chemical Control

192-P

Field evaluation of fungicides for management of rice false smut and kernel smut.
X. ZHOU (1)
(1) Texas A&M University System, AgriLife Research, Beaumont, TX, U.S.A.

Rice false smut (Ustilaginoidea virens) and kernel smut (Neovossia horrida) occur throughout the southern U. S. Both diseases can reduce yield and quality, causing significant monetary losses. Recent epidemics in many areas have drawn more attention to the need for their control. All major rice cultivars are susceptible to these diseases. Field trials were conducted in 2010 and 2011 to evaluate the efficacy of seed treatment and foliar application of fungicides for control of false smut and kernel smut. Seed of the rice cultivar Cocodrie was inoculated with the spores of both fungi prior to planting. Plots were spray inoculated with these pathogens again at the flowering stage. Seed treatment with trifloxystrobin (Trilex 2000) or metalaxyl (Allegiance LS) significantly increased stands and reduced severity of false smut and kernel smut compared to the untreated control. Single foliar application with propiconazole plus trifloxystrobin (Stratego) at the heading stage also was effective in reducing false smut and kernel smut. Combinations of seed treatment with a foliar application of Stratego were more effective than treatments used alone. Treatments did not significantly affect yield. Fungicides appear to be effective for management of false smut and kernel smut in rice.