Diamond for Southern Corn Rootworm Control Peanut Notes No. 148 2020

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Question (paraphrase):

Does Diamond sprayed twice at 6 oz/acre with fungicides serve as a good alternative to Lorsban (chlorpyrifos)?

Jordan Answer:

I am going to forward your question to Rick. Have those recommending this ever looked at an untreated area versus a treated area in the same field?

Answer:

Not sure. I never have.

Jordan Answer:

I don’t think there is any evidence that Diamond controls rootworms. Rick has looked at a lot of products over the years and nothing controls rootworms other than Lorsban.

Brandenburg Answer:

Diamond is a chitin inhibitor that to my knowledge doesn’t even have any insects even closely related to a rootworm on the label. I am aware of no data to support this claim.

Jordan Follow Up:

Keep in mind that we might not see injury from a pest but that does not mean a product controlled the pest even though it was used. The cause and effect relationship is important to establish. Rootworms are a good example. We have many fields where this pest never develops regardless of whether or not we treat.