ARS | Publication request: Crop management strategies and disease resistance control the severity of false smut and kernel smut of rice

Submitted to: American Phytopathology Society
Publication Type: Abstract Only
Publication Acceptance Date: May 1, 2009
Publication Date: June 1, 2009
Citation: Brooks, S.A., Anders, M.M., Yeater, K.M. 2009. Crop management strategies and disease resistance control the severity of false smut and kernel smut of rice. American Phytopathology Society 99:S17.

Technical Abstract: False smut and kernel smut are common diseases of rice capable of severe epidemics with dramatic yield losses. The importance of rice smuts is often overlooked in the US, and highly susceptible varieties are now being grown on the majority of production acres in the southern rice producing states. Our objectives were to identify crop management practices that affect smut severity on susceptible rice varieties and to identify factors that may promote or reduce disease. Concurrently, rice germplasm was evaluated for the long-term goal of identifying disease resistance. Using a long-term rice cropping systems study we evaluated the effects of tillage, crop rotation, irrigation, and fertility on smut severity. In an independent study designed to maximize disease pressure, smut severity was evaluated in rice varieties to identify resistance. As expected both diseases responded positively to increasing fertility, and the principal rice culture system (rice-soybean rotation, tilled soil, high fertilizer input) was found to promote the highest levels of both diseases. Conversely, fertility moderation, conservation tillage and continuous rice cropping all dramatically reduced false smut severity on susceptible rice varieties. Kernel smut was moderated only by reduced nitrogen fertility. All rice varieties tested were susceptible to false smut, but two rice hybrids were identified that were resistant to kernel smut.