Crop Scan AgReport – Big Response to Summertime Heat
August 9, 2021 
Cotton Grower® magazine’s Crop Scan AgReport for early August shows an overall crop that’s responded positively to a few weeks of summertime heat. Insect treatments are taking priority as fields in some geographies move toward cut-out, while west Texas growers are still watching weeds closely.
Chad Harrell owns and operates Harrell Agronomic Services in Northeastern North Carolina. He is a member of the North Carolina Agricultural Consultants Association and serves on the board of the North Carolina Cotton Producers Association.
We are currently at the fourth week of bloom on most cotton, with the later planted cotton being a little behind. Right now, it’s just wet. We have received about 3 to 6 inches of rain over the last week.
The moth flight has shown up but doesn’t seem to be as heavy as years past. All 2-gene cotton has received a treatment for worms while the 3-gene seems to be holding up good so far. We are finally starting to see a decrease in lygus except for hot spots, while stink bug pressure has picked up.
Looking ahead, our cotton crop is setting up very nice. Most areas received adequate rain during July and early August, giving us good fruit retention. The early planted cotton shows to have a really nice boll load. I think we can see some big yields this year if we can avoid any hard lock in September. The crop seems to be on schedule for a normal harvest this year. Due to the leaching rains that we’ve had, I don’t think we will be waiting around on a late top crop. Some of the earlier planted cotton should be ready to defoliate in late September.
Wes Briggs is an independent consultant providing recommendations on weed, disease, insect and fertility management, plus variable rate soil sampling, for growers in Georgia, Alabama, and Florida for more than 30 years. He and his scouting team cover about 10 counties in the tristate area, checking cotton, corn, peanuts, soybeans, and some small grains.
Currently we are watering cotton twice a week in spots, while some areas still have good moisture. We received enough dry weather to allow growers to catch up on weed control and fertility issues. Thankfully, weed control is 95% behind us, drying off just in time before the dicamba July 31 deadline.
Our sandy ground has required extra nitrogen this year. Fertility has been a moving target all year. Early planted cotton is probably two weeks behind normal due to wet conditions earlier. Luckily, having the ability to inject fertilizer through pivots has kept cotton in check, but expensive.
Our Bollgard II has been aggressively managed for corn earworm escapes, triggering sprays based on egg lay. There is no time to make up for damaged bolls and playing catch up this year.
August through the middle of September will most likely determine cotton yields in southwest Georgia, north Florida, and southeast Alabama. August can throw a lot at you – too wet, too dry, extreme humidity, nematodes, fertilizer deficiencies, foliar diseases, plant bugs, and stinkbugs to name a few. If we can somewhat control water requirements during this timeframe, cotton yields are generally 1,200 pounds and better.
Looking forward into August and September, our primary focus is stinkbug management. Stinkbug numbers are higher than the last couple years, and we are currently seeing continued cycles turning in peanuts. I fully expect stinkbugs to be a problem all way to defoliation. We must monitor square retention in both early and late planted cotton this year. We need to finish out our top.
Plant bug management along with timely PGRs will be important. Generally, we make our best cotton when crack boll coincides with cut-out, meaning at 100 to 105 days “crack boll,” we are at two to four Nodes Above White Flower (NAWF). Cotton at five to six NAWF at crack boll generally points to earlier retention problems such as plant bugs or poor PGR management.
Cotton is behind schedule some, but generally we always get enough heat units to finish out a crop. What’s concerning is the wet conditions earlier and the lack of fertilizer to finish out the crop could lead to premature cut-out and early defoliation for some that could not correct issues. On most of what we scout, I would rate yield potential to still be very good. Our growers have done an excellent job turning the crop around in the right direction.
The last four years have not been nice to the Southeast – 2018 and 2020 being some of the better cotton crops in my career with little to none harvested. In 2017 with Hurricane Irma and 2018 with Hurricane Michael, we saw 100% crop loss. In 2019, we had severe silverleaf whiteflies, and Hurricane Sally in 2020 unleashed the sixteenth wettest fall in 129 years. With only one mediocre year out of the last four seasons, yields again this year look promising, but we need warm weather thru Mid-September with the ability to manage water.
I rate our cotton crop today as 50% average to above, 30% excellent, and 15% to 20% below average. Probably 10% of below average is too far gone to turn around as it was just too wet for too long. This season has been challenging, but we’ve not lost this crop. If we can get good weather through August and September, we’ll be ok.
Tucker Miller is a Mississippi-based independent private consultant for cotton, soybeans, corn, peanuts, rice, and vegetables. He is a member and past president of the Mississippi Agricultural Consultants Association.
Our oldest cotton is at 23 nodes and fruited up nicely. Our later cotton has made up a week’s time and is at 20 nodes. With no rain in sight, we are irrigating down the row for what I hope is the last time. We really could have used a good rain the first week in August.
We are spraying our second round of bollworm in the Bollgard II varieties at this time. We are getting a heavy egg lay both in the terminals as well as on bloom tags.
Our plant bug control has been good this year except where we have cotton right next to corn. We have struggled to set fruit on these edges by corn. We are applying our last PGR shots on some of the later irrigated fields at this time.
Hopefully we are winding our insect applications down to isolated areas after this week. We haven’t seen any armyworm or loopers yet, and our aphids and mites have subsided. I am looking forward to this season being over. We are probably around two weeks later than normal. With good weather, we should bring this crop on in.
Mark Nemec is a Texas independent agricultural consultant, now in his 27th year of checking cotton, wheat, grain sorghum and corn in the Blacklands and Brazos River Bottom area of Central Texas.
Things in Central Texas have really turned around in the last couple of weeks. The summertime heat finally came, and the cotton responded to it very well. Most of the fields are reaching cut-out now, if not already past it.
Moisture is fading fast now that bolls are filling. Some irrigation is going out in the Brazos River Bottom to try and fill out as much as possible. PGRs have been going out to try and level off some of the growth on the more rank cotton.
We’ve had a pretty good run of stink bug pressure the last couple of weeks, and this could continue especially on later cotton for a little while longer. Worm pressure has been light all year with almost no treatments going out. Some spider mites are popping up in some hot spots with the dry weather now.
We’ve got our fingers crossed for a smoother finish to this crop than we had to start with.
Kerry Siders is Texas A&M AgriLife Extension Agent-IPM for Hockley, Cochran and Lamb Counties, providing education and applied research for weeds, insects, diseases, nematodes, growth regulators and harvest aids in cotton. He is a member of the High Plains Association of Crop Consultants.
Here on the Southern High Plains of Texas, cotton ranges from just beginning to bloom with more than 6 nodes above white flower (NAWF) to past physiological cutout with 3.5 NAWF. Using our IPM scouting fields as a representation of the area cotton crop, we see that 20% of fields have reached physiological cutout (<5 NAWF) this week. For those fields, we need approximately 400 more heat units (HU) to accumulate to be safe from bollworms. With the current weather trend of +17.5 heat units per day, those fields which have reached cutout should be safe from bollworms around August 29.
The remaining 80% of the cotton acreage has such a wide range of maturity levels that it would be difficult to be as certain of when it will be safe from worms. I would approach these later maturing fields from this angle. We historically say our last effective bloom date is August 20. This is a date in which a boll can be formed, have time to mature, and contribute to yield. Therefore, if we continue with this weather pattern into September, and we are accumulating 17.5 HU/day, we can add 23 days to this date. That would give us a target of September 12 for those late fields needing to be scouted and protected from worm issues. The point being, NAWF is an important gauge of maturity and can help project time needed to be safe from worms and even manage irrigation.
Currently, bollworms are just beginning to be found infesting area fields and need to be scouted, particularly those varieties with lesser than Bollgard II or no Bt technology. Lygus, stink bugs, and cotton aphids should be included in those scouting procedures.
Cotton aphids have been the most prevalent insect in many acres. To date, beneficial insects such as lady beetles and lacewing have kept up and cleaned up most of the infestations. Remember, cotton aphids thrive in skippy cotton and excessive/late nitrogen. Late nitrogen can also delay cotton maturity.
More information on managing cotton insect in Texas can be found in this online report.
Here’s my priority list for the rest of August and going into September:
- Keep a close watch on cotton bollworms, larva pests in general, cotton aphids and lygus. Scout, apply economic threshold, and act on good information.
- Continue with late season weed control: residual herbicide, cultivate, hoe…whatever it takes to keep the pigweed from going to seed. It is a numbers game.
- Be careful when irrigating not to cause additional vegetative growth resulting in delay of plant maturity. The goal is to be done blooming before the end of August.
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