Submitted to: Rice Field Day Abstract
Publication Type: Experiment Station
Publication Acceptance Date: June 7, 2013
Publication Date: June 25, 2013
Repository URL: http://www.//beaumont.tamu.edu/eLibrary/Newsletter/2013_Highlights_in_Research.pdf
Citation: Zhou, X., Mcclung, A.M. 2013. Use of bacillus biocontrol agents for disease management in organic rice. Rice Field Day Abstract. Beaumont, Texas Rice July 2013 edition, Special Section: XXII-XXIII. Technical Abstract: Organic rice production has significantly increased in the U. S. over the last decade. Organic rice growers lack effective tools to manage sheath blight, caused by Rhizoctonia solani, and narrow brown leaf spot, caused by Cercospora janseana, two major diseases affecting organic rice production. This study evaluated the efficacy of bacterial biocontrol agents (Bacillus) for control of these diseases and impact on yield. An experiment was conducted in a field under organic management at Beaumont, Texas in 2010 and 2011. Plots were inoculated with R. solani at panicle differentiation. Narrow brown leaf spot developed from natural inoculum. At the boot stage, plots were sprayed with a single application of Serenade Max (Bacillus subtilis strain QST713, 14.6% active ingredient), Serenade ASO (B. subtilis strain QST713, 1.34% a.i.), or Ballad Plus (B. pumilus strain QST2808, 1.38% a.i.). Untreated plots served as the controls. Severity of sheath blight and narrow brown leaf spot was rated near harvest using a scale of 0 to 9, where 0 represents no symptoms, and 9 represents severe symptoms. Plots were harvested at maturity using a plot combine, and grain yield adjusted to 12% grain moisture. Serenade Max and Serenade ASO were effective in reducing sheath blight severity over two years . Serenade Max also reduced narrow brown leaf spot but Serenade ASO did not. Ballad Plus was ineffective in decreasing either disease. Among the three biocontrol agents evaluated, only Serenade Max consistently increased yield compared to the control by more than 15% over 2 years. Serenade Max can be used as an effective tool to minimize the damage caused by sheath blight and narrow brown leaf spot in organic rice. Serenade Max is a commercially available biopesticide certified for organic production of rice and other crops.