Jonathan Croft, county agent in Orangeburg County, said has “heard about some thrips on some cotton. Most is slow growing with these cool nights. Dry conditions are also starting to slow planting of cotton in some fields.”
Jay Crouch, county agent in Newberry County, reported that “cotton planting (is) just getting up to speed my way. Cool wet conditions slowed us a bit.”
As this week ends, it has certainly warmed up, but it has gotten dry in the southern half of the state. The northern half received some rains last week that we missed down here.
Thrips, grasshoppers and false chinch bugs are the most pressing issues with insects right now.
Thrips pressure has been moderate in my research plots so far this season…not nearly what we saw last year. Most at-plant treatments are providing good protection, but the seed treatments are weaker than products put in the furrow not on the seedcoat.
Plots treated with aldicarb (AgLogic) continue to look the best right now (3-leaf stage). Foliar sprays are doing fine, except for the pyrethroid, with Radiant, acephate, and Bidrin looking good on thrips.
Last year, a large population of thrips went through my trials, and Radiant, Orthene, and Bidrin were the best foliar sprays for thrips.
Real Issues With False Chinch Bugs
We have noticed a ton of false chinch bugs (FCB) in our foliar test using untreated (black) seed that were planted about 8 days after burndown.
This is a good example of what not to do with a late burndown and planting too close to that event, especially if you have an issue with an at-plant treatment for thrips.
Check out the video in this Twitter post to see false chinch bugs in action.
Unprotected (no seed or in-furrow trts) 2-leaf cotton seedlings with significant injury from thrips and false chinch bugs. This is why we use a preventative insecticide. Almost any insecticide used at planting will prevent this. pic.twitter.com/OAWFYHaXrt
— Jeremy Greene (@bugdocisin) May 11, 2020
In an adjacent trial, we don’t have any problems with FCB, as long as something was used for thrips at planting. All insecticides except for Radiant are providing control of FCB.
We are starting to see some aphids in that at-plant trial and will continue to monitor population development of cotton aphid.
For problems with grasshoppers, use a high grasshopper rate of acephate for adults and the insect growth regulator (IGR) Dimilin (2 fl oz/acre) for keeping the nymphs from becoming adults. This IGR is great for grasshoppers.
I have some soybeans at V1/V2 in a planting date study planted mid-April, and, again this week, no insects have found them yet, as far as I can tell. We are also still successfully keeping the deer away with a 1-ribbon fence.
I am anxious to see if kudzu bugs jump on these early-planted soybeans soon like they did last year. They were the most numerous insect pest in this trial last year.
Grasshoppers continue to be an issue in spots in both cotton and early-planted soybean. Use Dimilin at 2 fl oz/acre to control the immatures and break the life cycle, but use a pyrethroid for some suppression of the adults that are more difficult to control.