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2014 Soybean Fungicide Considerations

Many producers opt to include a fungicide with an insect application with anticipation of increased soybean yield as well as to obtain at least some protection against any potential Soybean Rust or other soybean diseases. Many product choices are available. A summary of potential fungicide products and fungicide efficacy is available at

Before automatically applying a fungicide, consider a few important factors. First consider that most data shows that optimum time for fungicide application is at soybean growth stage R3. Most fungicide applications are made with insect applications at a slightly earlier soybean growth stage. Thus, some potential yield enhancement may be lost due to early application. Even when applied at proper soybean growth stage, data from NCSU shows a slight (2-3 bu/ac) increase on average. Soybean growers should evaluate potential financial benefit based upon this 2-3 bus/ac increase in yield and the current soybean price compared to the cost of product and application. The financial benefit from such a small yield increase may be marginal with lower soybean prices.

Another critical factor regarding fungicide application is the management of the potential disease, Frogeye Leaf Spot. This disease has developed resistance to the class of fungicides known as strobilurins. Thus varietal resistance or utilization of other classes of fungicide is required to control this disease. Many varieties are bred with resistance to this disease. Soybean varietal resistance for Frogeye Leaf Spot, Southern Stem Canker and Sudden Death Syndrome is available for review at

For additional soybean production information as well as comments from NCSU faculty regarding seasonal circumstances, visit the NCSU Soybean Information Website.

For questions pertaining to this article or soybean production within Craven County, email Extension Agent, at:

Follow the author on Twitter at: @mcarroll_craven