Evaluation of Sequential Fungicide Spray Programs for Control of Soybean Rust

Abstract

Soybean rust (SBR), caused by the fungus Phakopsora pachyrhiza, has been a recurring problem for soybean growers in the southern United States. In some cases, growers in this region have followed a fungicide spray program consisting of two fungicide applications to protect their crop from the disease. Our study was conducted to determine how various sequential fungicide spray programs perform under the relatively high SBR pressure found in Alabama. Results from this study suggest that there are significant differences in the relative effectiveness of a program based on products used and the sequence in which they are applied. Factors such as recent weather conditions, proximity to sources of SBR, cost of available products, and an estimate of a crops yield potential should be considered when choosing a fungicide program.Accepted for publication 10 February 2009. Published 2 April 2009.Our study was conducted to determine how various sequential fungicide spray programs perform under relatively high soybean rust (SBR) pressure found along the gulf coast of Alabama. Results from these trials will provide growers with information on the performance of products and/or product combinations and allow them to make informed decisions on selecting the best management program for SBR.