Submitted to: Plant Disease
Publication Type: Peer reviewed journal
Publication Acceptance Date: 3/29/2011
Publication Date: 8/1/2011
Publication URL: http://handle.nal.usda.gov/10113/58014
Citation: Brooks, S.A., Anders, M.M., Yeater, K.M. 2011. Influences from long-term crop rotation, soil tillage and fertility on the severity of rice grain smuts. Plant Disease. 95(8):990-996. Interpretive Summary: False smut and kernel smut are fungal diseases of rice that reduce both total yield and quality of the rice grain. Most rice varieties grown in the United States are susceptible to these diseases. How these diseases respond to changes in crop management practices is also poorly understood. By using combinations of crop rotation, soil tillage and fertilizer rate, several alternative crop management practices were identified that provided effective control of the smut diseases. The most effective method was with three-year crop rotations where rice was grown every third year. Regardless of rotation order, or subsequent tillage and fertility treatments, rotating out of rice for two years was the most effective approach for smut control.
Technical Abstract: False smut (Ustilaginoidea virens) and kernel smut (Neovossia horrida) are diseases of rice (Oryza sativa) that reduce both grain yield and quality. Susceptible rice varieties are in widespread use on production acreage in the United States, and the effects from crop management practices on smut control are poorly understood. The highest levels of false smut observed in this study were on varieties grown in rotation with soybeans, on traditionally tilled soils, with high fertilizer treatments. The highest levels of kernel smut were observed in a rice-soybean rotation with winter wheat grown between spring crops. These rotations are commonly used in rice growing regions of the southern U.S. Using combinations of crop rotation, soil tillage and fertility rate, several alternative crop management practices were identified that provided effective control of smuts in susceptible rice varieties. The most effective method for controlling both false smut and kernel smut was in three-year rotations of rice, soybeans and corn. Regardless of rotation order, or tillage and fertility treatments within the rotations, rotating out of rice for two years was the most effective approach for smut control.