Impact of Cropping Sequences and Alternative Hosts on Take-all Management of Winter Wheat in Arkansas

Abstract

Cultural practices are the principle means for managing take-all of wheat caused by Gaeumannomyces graminis var. tritici. This research identified cropping sequences that can be used to manage take-all in Arkansas. For dryland fields where the opportunity to grow rotational crops is limited, summer fallow was the best option for managing take-all. For irrigated fields, rotation out of wheat for at least one year reduced incidence and severity of take-all, and rice was the most effective rotational crop. Summer fallow or a rice crop was more detrimental to survival of take-all inoculum compared to corn or soybean. Reductions in inoculum were associated with elevated soil temperatures during the summer in fallow fields and with soil anoxia in flooded rice fields. Managing grassy weeds is important during rotations out of wheat. Rescuegrass was the most susceptible grassy weed to G. graminis var. tritici in this study. Although Italian ryegrass was only moderately susceptible, it likely plays a major role in maintaining inoculum because of its wide distribution and large population size.Accepted for publication 11 April 2009. Published 12 May 2009.