A sample from the soybean sentinel plot in Coffee County collected August 29th contained very low levels of soybean rust. Late planted soybeans in the area are at risk and would benefit from a fungicide application.
Other sentinel plots across Tennessee have been monitored and continue to be monitored for diseases and invasive insects. To see where soybean rust has been confirmed visit sbrusa.net (screen shot image below). The sample from Coffee County had 2 leaves out of 54 with soybean rust pustules. Overall severity was less than 1% (image below is one of the sporulating pustules from the sample). The Coffee County location was planted May 22, on 15″ centers, and is not irrigated. Frogeye leaf spot levels on susceptible varieties continue to increase as well as septoria brown spot across Tennessee.
With rain in some of the forecasts, later planted soybeans that are earlier than reproductive growth stage R5.5 (before seed is touching in the pods) are at risk and can be protected with a fungicide application, if one has not already gone out. For more information visit UTcrops.com under Soybean –> Diseases and Nematodes. See the fungicide efficacy table to better pair a fungicide to manage multiple diseases.
