A website from UGA Cooperative Extension

Cotton and Peanuts

It has been relatively quiet in terms of disease and insects with the exception of thrips. Thrips damage is evident in nearly every cotton and peanut field I have been in. Many of you have already treated fields; some even behind AgLogic. I believe this is due to the lack of rain and plants not taking the insecticide up in dry fields. I think this final push from thrips in our fields over the last couple of weeks is also due to dry weather, which has them looking for anything green. However, once cotton reaches the 4-leaf stage and peanuts reach roughly 4 weeks old, the plants are strong enough to handle thrips damage, and a foliar application will probably not pay for itself.

Thrips damage on young cotton

Corn

I have received a few calls this week about applying fungicides on corn. As most of our corn is approaching or already is at tassel, this is a great time to be thinking about applying a fungicide to protect against foliar diseases, most notably southern rust. However, I do not think it is a bad idea to hold off on spraying at this time. I say this because no southern rust has been found in the state as of today. But with that being said, it is never a bad idea to be on the safe side and go ahead an apply that fungicide.

Corn at R1 stage

I did want to share a different kind of rust I found while walking some corn this week. The following picture is of common rust, not southern. Common rust is more of a burnt-orange/brown and southern is bright orange, common is usually more elongated and southern is usually more circular, and common will have pustules on both top and bottom of the leaf while southern is only on the top. Common is rarely a concern in our area, while southern can cause major yield loss.

Common rust on upper leaf surface
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