Be Patient with Head Scab Applications

I have been getting a lot of questions about spraying fungicides such as Caramba early to control Fusarium head blight in wheat, commonly known as “head scab.” With wheat heads out and heavy rains in the forecast late this week for much of Illinois, farmers are wondering if they should spray now in case they can’t apply later. My advice is to be patient and make sure you are giving your fungicide a chance to be successful.In "order" to get the most benefit out of a fungicide application for head scab, the wheat heads should be flowering. The optimum timing is beginning flowering (Feekes 10.5.1), highlighted in the image above, but research indicates that fungicide applications delayed 5-7 days past Feekes 10.5.1 can still be very beneficial. However, applying a fungicide prior to flowering will significantly limit the benefits in terms of yield and mycotoxin prevention. Adapted from independent “Meta-Data” report from the U.S. Wheat and Barley Scab Initiative shows the best fungicide timing for FHB control and DON reduction should be applied at or shortly after anthesis.*

This is a rare case where delaying fungicide applications is the better option, so again I would advise patience and don’t spray until the wheat has flowered. Below are links for additional information about head scab control.

https://crop-protection-network.s3.amazonaws.com/publications/cpn-3001-wheat-optimizing-fungicide-use-for-fusarium-head-blight-scab-and-associated-mycotoxins.pdf

*http://scabusa.org/pdfs/nfhbf14_GS3_Madden.pdf

Always read and follow label directions.