Defoliation has started in the lower Southeast. However, growers will likely ratchet down their enthusiasm until they gain a better idea about when and/or where Hurricane Dorian will make landfall next week.
Boll rot and target spot are emerging in more fields, and late-season rains are beginning to affect open bolls and yield potential. In a “good news, bad news” scenario, target spot may reduce boll rot by dropping leaves and opening the rows.
The “stinky” season isn’t quite over in many areas. Growers are encouraged to stay vigilant against stink bugs until harvestable bolls are 25 days old.
Manage whiteflies until the last leaf drops. That’s the consensus from Extension entomologists. As long as a cotton plant has leaves, whiteflies can harm quality.
Also Of Note: In this week’s link section, connect to market analysis from Don Shurley and Jeff Thompson, plus yield estimates from Texas and the Southwest.
LAST REPORT FOR 2019
With more cotton moving past cutout and defoliation cranking up, this will be our final regular report for 2019.
Our thanks to:
Amvac and its Southeast Cotton Team for sponsoring this year’s coverage. We greatly appreciate their support.
The folks in the field who update us on crop conditions and issues. We are grateful for their patience, knowledge and insight. This publication would not be possible without the help of these consultants, dealer personnel and Extension professionals. In a sense, they are the editors. We simply gather their reports and pass them along.
David Butcher, NC Ag Service, Inc., Pantego, North Carolina:
“Overall, crops look pretty good. Corn yields aren’t setting any records. The average is probably a little lower than normal, with yields significantly lower on sandy ground.
“About 5% of our cotton is so far behind that it is still flowering, but we don’t have any heavy insect pressure. Our moth flight was light this season and most of the cotton has matured beyond the threat of stink bug damage.
“In soybean, we’re finding a smattering of cloverworms and other foliage feeders but have only needed to treat a small percentage of fields.”
Jeremy Greene, Clemson University Entomologist, Blackville, South Carolina:
“What insects we had this year have moved out of cotton, and symptomology for the dwarf leaf curl virus doesn’t seem to be extreme anywhere. With this accelerated crop, our’ stink bug month’ started early, around July 15, and ended early in mid-August. Where anyone has spider mite pressure, this rain is suppressing them.
“In soybeans, we still are finding a range of different species. The only one causing a problem is velvetbean caterpillar (VBC). We dealt with a population in Elloree that was tough to kill. The grower sprayed the field twice with a pyrethroid and didn’t kill them. So, I collected some and brought them back to the lab for testing.
“Control with cyfluthrin was 9% at 24 hours. Control with bifenthrin was 90% at 24 hours. At 24 hours with anything else, we killed less than half of them. Bifenthrin and cyfluthrin are both pyrethroids, so that’s a head-scratcher, considering the difference in efficacy. I don’t know what to make of it, but I would spray bifenthrin if I needed to treat VBC in a South Carolina soybean field this year.
“Since VBC doesn’t overwinter in South Carolina, we don’t need to be alarmed. This was likely a migratory population that had been sprayed with a variety of materials before they arrived here. Pockets like this occasionally show up here and in various other states. They are normally a highly susceptible species, and we typically can kill VBC with just about anything. We will put out a test to ensure that this was only an isolated case.”
Brandon Phillips, Phillips Ag Services, LLC, Fitzgerald, Georgia:
“We started defoliating a little cotton last week, and more applications will go out this week. Next week, a whole bunch would be ready. For now, though, we’re holding back to see what this storm (Dorian) out in the Atlantic decides to do.
“We will treat 10% to 15% of our late May- and June-planted cotton for whiteflies. When you mention whiteflies, everyone immediately thinks about 2017. However, they’re not exploding this year like they did two years ago.
“We are treating for target spot on some later planted cotton. We sprayed only 10% to 15% of our fields this year for target spot, which is about half what we usually treat. It showed up later this year, so we didn’t need to make as many applications.
“Our irrigated cotton crop went from excellent to good after boll rot ate our lunch. Rain is a double-edged sword. Some of our crops needed it, but others didn’t. It’s hard to put a number on the yield loss. If an irrigated field was going to make 1,500 lb/acre and we have 10% boll rot, that’s 150 pounds we lost. For the most part, our dryland yield will be about 750 lb/acre.
“In peanuts, the issues include worms, white mold and spider mites. We seem to have had a never-ending flight of velvetbean caterpillar for the last month to six weeks. We treated with Prevathon, which held them for about 28 days. Now, we have to treat again.
“We will start digging a majority of our acres late next week and will be surprised if we average what USDA predicts, which is about 4,400 lb/acre. We have some really healthy irrigated peanuts but also have some rough looking dryland peanuts in places. If we average 3,000 lb/acre on dryland, we’ll be amazed.
“On a brighter note, our corn crop turned out well, and we’ll probably averaged 220 to 230 bu/acre.”
Dominic Reisig, NCSU Extension Specialist, Entomology, Plymouth, North Carolina:
“A majority of our soybean acres have lower-level populations of corn earworms, stink bugs and kudzu bugs. With a small percentage of acres, we’re dealing with kudzu bugs, which hasn’t happened in recent years. The heaviest concentration was in Johnson County, which is normal with this insect.
“For each of the last six years, except for 2017, people have reported soybean fields with yellow, curling leaves. Many think it’s potato leafhopper burn, but it’s not. This is showing up in multiple states, mostly in Group VI and VII soybeans, and it varies by year. Nobody can figure out what is causing this, although my gut feeling is it’s an environmental-germplasm interaction.
“Now, it’s time to pray for good fall weather.”
Eddie McGriff, Regional Extension Agronomist, Northeast Alabama:
“A slow, soaking rain fell on north Alabama early this week, which boosted late-planted beans and will help us finish up the cotton. Dryland corn yields vary widely, from 30 to 200-plus bu/acre.
“Stink bugs are the one thing that can cause us problems right now in our cotton. Brown marmorated stink bugs are persistent, and they will attack an older boll. They definitely can damage the borders of a field.
“In all crops, the impact of nematodes is showing up late. This is an opportune time after the rain to take nematode samples. In particular, sample weak spots in the field. Compaction layers that are two to three inches deep constrict the roots and amplify the effects of nematodes and drought stress.
“We will start desiccating soybeans early next week, mostly the early-planted Group IVs.
“Peanuts look healthy. The only insect issue has been potato leafhopper burn. A grower might notice it on field edges, but I haven’t seen any yet that warranted a treatment.”
“It’s been a challenge to manage this cotton crop, considering the wide variability in development within fields. On the other hand, insect pressure has been light, which has given us a huge break. We started defoliating a few acres this week. That said, about 30% of our cotton won’t be ready for harvest until December. The deciding factor in making that crop will be when the first frost hits.
“In peanuts, growers have treated the odd field for lesser cornstalk borers. Plenty of caterpillars are around, mainly velvetbean caterpillars, but most are running below threshold. Digging will start in about the next 10 days. By the end of September, we will have dug about half the crop. We should harvest the more timely-planted peanuts in the first two weeks of October, I suspect. However, our late-planted peanuts this year are still some time from being ready.”
Steve Bullard, CCA, BCT Gin Co., Quitman, Georgia:
“Stink bugs and scattered incidents of whiteflies are the only pests putting pressure on cotton. In young cotton, we will need to put out another PGR treatment and possibly a stink bug spray. We hope to squeeze by without treating some of this older cotton – so we can spend that money on defoliant.
“We started defoliating a small number of acres last week. Mostly, we’re finished with treating insects, and cotton is opening in nearly every field.
“We started blasting peanuts this week, and they probably need another 12 to 14 days before digging. We are seeing white mold hits, but nothing alarming.
“Some fields missed out on timely rain, but our crops look good overall. Now, we need a dry and a safe harvest season.”
Sally Taylor, Virginia Tech Extension Entomologist, Tidewater REC:
“Corn earworm numbers are up in many parts of the state. Infestations in soybeans are spotty, vary by location and even vary by maturity groups within the same area. Keep in mind that broad-spectrum insecticides kill predators that work on stink bug eggs and small caterpillars, so spraying without scouting can increase late-season pest pressure.
“Peanuts and cotton are largely safe from insects now. Even though you can find high numbers of adult moths in some cotton, that doesn’t necessarily translate into bollworm damage. Remember that those late-maturing bolls represent 10% or less of your total yield, so an application this late in the year will likely not pay off.”
Kevin Cotton, High Cotton Consultants, Leesburg, Georgia:
“The big thing right now is target spot, and it’s blown up in some fields. It has provided a little benefit by cleaning leaves out of the bottom where boll rot has developed. A good deal of our cotton also has lodged and is twisted and tangled due to the weight of bolls.
“The crop still has good potential, but much depends on what our weather does from this point. Dry weather is certainly needed. I’m going to be optimistic – hopefully, the Lord will smile down on us and we will harvest good yields.
“Peanuts are healthy and producing well in fields where we could go with a better disease management program. We have velvetbean caterpillars and loopers in the peanuts and have treated a few fields. The rain this week will help with spider mites in peanuts. Certain fields probably should be treated, but between the rain and being so close to the end, we will hold off at this point.
“This won’t be a record-breaking crop, but it should be decent. We will start digging late next week.”
Ron Smith, Extension Entomologist, Auburn University:
“The stink bug complex, along with the leaffooted bug, continues to be the issue that could decrease yields. We have never had pressure this heavy this late in the season. Leaffooted bugs are showing up in more areas of the state than ever. Brown marmorated stink bugs (BMSB) are in fields from the Gulf Coast to the Tennessee Valley.
“With BMSB, you have to spray your field borders multiple times a year to keep them from inflicting damage. As long as we have young bolls that we expect to bring to harvest, pay attention to this overall complex.
“Velvetbean caterpillar (VBC) exploded in scattered soybean and peanut fields this past week. Low numbers of soybean loopers are in the mix, but I rate VBC as the primary problem. If you’re not watching those fields, you could end up with a lot of stems and no leaves. The greatest area of concern is in the southern tier of counties in Alabama and in the Florida Panhandle.”
“When do you terminate insecticide treatments? Many growers begin asking that question every year at about this time. The answer depends on which insect is in the field.
“We need to protect cotton from whiteflies until all the leaves have dropped. That’s what it takes to preserve quality. I know we don’t want to spend any more money on this crop, but when whiteflies are the issue, we can’t afford to let them go.
“Recent rains have slowed whitefly development, but rain will not eliminate the problem. A thunderstorm will knock down some of the adult population, but rain has little impact on eggs and immatures.
“Generally, we are continuing to treat whiteflies in our historic areas. We also see whiteflies building in many areas outside their typical range. Quite likely, whiteflies will move into our June-planted cotton in the next couple of weeks. Watch and scout. It’s critical to stay on top of whiteflies, to prepare to treat and react without delay when it’s time. If whiteflies get ahead of us, it’s expensive and challenging to play catchup.
“For stink bugs, protect cotton until the last harvestable boll is 25 days old. You know a boll is 25 days old when it is fully sized and it’s hard to burst between your thumb and forefinger.
“Overall, we’re still in great shape insect-wise. Just stay on top of things, don’t let your guard drop. Defoliation is starting. Where applications have gone out, that cotton looks like it will yield well, and we sure need every pound this year.”
This weekly report is distributed during the cotton production season. It is available to United States residents engaged in cotton farming, field scouting and other qualifying ag professions. Mailing address: 142 Westlake Drive, Brandon, MS 39047. Office: 601-992-9488.