by AgFax Media LLC, AgFax.com
Defoliation started this week in northeast Louisiana in a small amount of early-planted cotton.
Frequent showers have kept cotton fields moist and susceptible to disease. Depending on the area, this weather pattern has been at work for 10 to 14 days. Amounts have mostly been in tenths of an inch, but the showers have developed often enough to keep cotton in a moist, humid environment. (Don't confuse this pattern with the devastating rains that caused flooding in parts of southern Louisiana and Mississippi.)
All the rain has triggered target spot on a wide basis. For the first time ever it's turning up in commercial fields in Tennessee and has been found in cotton as far north as Carroll County, which is a couple of counties south of the Kentucky line. Target spot also has been found in areas in north Mississippi where it's never been a factor. Defoliation in the lower canopy has become very obvious, and people in the field are taking note of which varieties appear to be sustaining the biggest hit. Weather-related shed is obvious in places, as well.
Bollworm slippage is being reported on a larger scale this week. Worms are making it through the seed technology or are surviving pyrethroid applications or both. Speculation is bubbling over about the cause or causes of these escapes. Are numbers simply overwhelming? Has Bt expression slacked off due to stress or crop maturity? Is resistance taking shape in bollworm populations? Entomologists will likely spend ample time over the winter sorting out the bodies.
The rain has complicated treatment timing where worms and other pests have hit thresholds. Many fields are too wet if growers wanted to spray by ground, and aerial applicators are backed up in many areas. And with these showers popping up seemingly out of the blue, treatments are at risk of being washed off before they become rainfast.
More cotton has moved past the point that people would put further money into protecting the latest blooms and squares, but late-planted cotton and green patches still bear watching. Plant bugs are lingering in some of that cotton. Fall armyworms are in the mix, as well.
LOUISIANA CROP REPORTS
Gary Wolfe, La-Ark Agricultural Consulting, Ida, Louisiana: "It's raining a little on most days – but it's been doing that for the last 10 days straight, so conditions have been consistently wet. Cotton is opening, so this is a bad deal. I've been through this before, of course, but it's never easy to watch what happens to bolls and lint in rainy weather.
"Aside from any effect it's having on potential for disease or boll rot, we can't do anything in the field. I'm also hesitant to pay for an insecticide and the aerial charges, then worry about whether the material will be washed off. It's raining often enough that we have no guarantee that showers won't develop right after the application.
"We've been guilty in some past seasons of going too far in terms of protecting late fruit. But as things stand right now, we'll sit back and take the damage. We've had 5 good weeks of bloom and 2 weeks of protecting pretty much what we'll make. As long as we don't have much shed we should be okay. We've got 90% to 95% of a crop now.
"Except for some late fields, we're backing away from further insecticide treatments. I've turned some irrigated fields loose and the dryland pretty much shut down after about 7 weeks without rain. In some of those fields the plants have added regrowth and a bunch of new squares, but I don't see the economics in protecting anything new. By the time we held onto those new positions long enough to make a boll, we'd lose too much at the bottom to boll rot. However, I am letting farmers decide how they want to approach this. Even where cotton is bolled up, we're coming across with a pint of Pix.
"A moth flight has settled on us, and some later cotton does need to be sprayed. At this point, it's also the farmer's decision – whether to go with Besiege and Diamond or treat with a pyrethroid. Last year we had a lot of slippage with worms. This year we tried to stay in front of them as much as possible. I'm finding a few scattered aphids and started dealing with plant bugs in some later cotton after corn harvest started."
Richard Griffing, Griffing Consulting, LLC, Monterey, Louisiana: "We're north of where the heaviest rain and flooding have hit Louisiana and those neighboring areas in Mississippi – but we're not much north of it. As of today (8/16) they've gotten 11 inches of rain in Natchez, Mississippi, which isn't far away. But at my house I've only poured 1.1 inches out of the gauge in the last 5 or 6 days. With most of my clients the totals have run 1.5 to 5 inches. It could be much, much worse. I'm hearing reports to our south of 2 feet of water standing in places.
"We'll wrap up things in cotton as soon as the weather breaks. Getting in these last treatments hasn't been easy. It's usually raining somewhere every day around noon, plus we've had fog. The application window has been very narrow, and the aerial applicators are backed up. We need to get one more plant bug and Pix application on most of the cotton.
"I just turned in my first defoliation recommendation for 2016 on some cotton planted around the first of April. That was on 500 acres. Another consultant had some defoliant going out this morning on 200 acres in Tensas Parish. Like me, he only had a limited amount of cotton planted early.
"We're seeing boll rot, which isn't surprising. Most all of the rest of our cotton is just opening up well, and we're a couple of weeks out from defoliation in any of it."
David Kerns, Entomologist, Louisiana State University, Macon Ridge Research Station: "We've mostly made our cotton crop and it's just a matter of finishing it out. With all the rain and moisture, we're seeing a lot of bacterial blight and also leaf spot diseases in the inner canopies. In a number of fields we're finding significant boll rot, with 10% to 15% of the bolls in some fields affected, and we can see it increasing. At this point, pests aren't the problem. It's the environment."