Soybean rust (SBR) has now been detected in 33 of the 67 counties in the state. The disease has been found in both commercial soybeans and in kudzu patches as far north as Cullman and Morgan counties. If you would like an update on the occurrence of SBR in Alabama or across the U.S. check out here.
Soybean fields that received a fungicide application with an appropriate product at the R3-R4 growth stage that have reached R5 (pod fill) or beyond likely DO NOT need a second fungicide application. Fungicides should not be applied for SBR control after the R5 growth stage.
Soybean fields at the R3-R4 growth stage may benefit from a fungicide application with a product that contains a triazole product as either a pre-mix fungicide or tank mix combination if the disease has been observed in your region of the state. Triazole fungicides have curative activity and will reduce severity of the disease in fields where SBR is already present. A combination fungicide (strobilurin/triazole) should give you 3 to 4 weeks of residual protection against SBR and other foliar, pod, or stem diseases.
Soybean fields in vegetative growth stages are at high risk to the disease this year. Fields should be monitored closely for development of SBR. A fungicide application with a product that contains a triazole should be strongly considered at the R2-R3 growth stage if the disease has been observed in the field or if conditions favor SBR development.