Late-Season Fungicide Use Peanut Notes No. 173

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Question from County Agent

I am working on sending out a newsletter this morning with pod blasting dates and wanted to include something about fungicide program from now to finish. What would be points to add for fungicide program from now to digging?

Answer from Dr. Barbara Shew

For fungicides applied now (this week), stem rot could still be a concern due to hot weather. Growers may want to use a fungicide that is effective against stem rot. These include Provost Silver, Fontelis, or a mixture of chlorothalonil + tebuconazole or chlorothalonil + Elatus. Keep resistance management in mind when choosing a fungicide. A group 7 fungicide (Fontelis, Miravis) should not be used in consecutive applications with itself any other group 7 product.

If stem rot is not a concern, consider an application of chlorothalonil + Alto. The label allows a maximum of two Alto applications per season.

For applications later in this month or in September, chlorothalonil is the best choice for fall leaf spot control since it helps to reduce selection for fungicide resistance. Site-specific fungicides from any resistance group (3, 7, or 11) applied after September 1 should be mixed with chlorothalonil to guard against resistance development and to protect against any resistant populations that may already be present. This usually is true even in fields where Sclerotinia blight is a concern.