2020 Cotton Crop Update

David Wright, Florida
David Wright

Florida cotton has good yield potential at this point. Weather has been mostly good for growing and fruit set. Many of our growers use conservation tillage when planting but may plant into winter fallow weeds while some plant into cover crops.

Our data over the years with cover crops shows that they can help with erosion control and moisture conservation but may not always increase yields.

However, data from the last 20 years of a long-term cotton/peanut rotation shows that if winter covers are grazed, fields that have often been breakeven in yields or less can be converted into some of the top yielding fields while using less nitrogen.

In addition, we have shown that 40%-70% less irrigation is needed, depending on the year, following winter grazing due to enhanced (almost double) rooting of cotton plants. This practice is beginning to be recognized by many of our cotton growers across the Florida Panhandle with cattle producers teaming up with row croppers to make this a mutually beneficial enterprise.
We have emphasized to growers to start with the worst fields that they have.

Every grower who has tried it has come back with positive stories. Yields can be increased by a minimum of 150 pounds per acre of lint up to 400 pounds per acre every year with grazing. We have not seen this with cover crops alone even if it is high residue.

Grazing takes most of the cover crop out but results in higher yields with less input. This gives farmers an incentive to plant cover crops that they would otherwise avoid because of the expense and lack of return in yield in many cases. Likewise, calf gains have been 50-100 pounds per head higher following row crops as fields are usually a little higher in fertility than many pastures.

I have heard many testimonies about ways that cattle and row crop producers are working together to make it profitable for both sides while contributing to soil health and other environmental services. wright@ufl.edu

STEVE BROWN, alabama
Steve Brown

Rapid fruiting describes most varieties in the field in 2020. Given built-in worm control, good plant bug management and favorable growing conditions, fruit retention through early bloom and boll set should be extremely high, perhaps 90% or better.

But we know we can’t retain every position. In 2019, I counted bolls on DP 1646 B2XF that picked almost 1,400 pounds per acre. Percent harvestable bolls versus possible fruiting sites was 43%. That seems low, but I suspect in the Southeast, no matter how good the yield, that number rarely exceeds 55% or 60%.

So how many weeks of flowering are needed for big yields? Last year, we participated in a Cotton Incorporated study in which we monitored growth stages and heat units. At three sites, days from first bloom to cutout (as measured by NAWF 4) was 28 days. Yields of DP 1646 B2XF in these trials ranged from 1,399 to over 2,100 pounds per acre.

“Cutout” suggests that the progression of fruiting and flowering is moving up the plant so rapidly that few additional meaningful, harvestable bolls will be set in the upper canopy. In the long seasons of the southernmost areas, some think that cotton may stay at 4 NAWF for a couple of weeks or so.

Granted, 2019 was extraordinarily hot, so plant processes were accelerated. Still, this indicates that in four to five weeks of bloom, we can make a very good crop.

Another implication is that in good growing conditions— and as of mid-July our Alabama crop looks extremely promising because of favorable rainfall — extra vigilance is needed through the first several weeks of bloom. While we might name several important management factors, especially critical in August are stink bug control and where possible, timely irrigation.

Every input, every decision builds the crop for boll production. These are key weeks for production and protection. cottonbrown@auburn.edu

Mississippi brian pieralisi
Brian Pieralisi

Mississippi experienced hot, humid and wet conditions for the first part of July. Cotton has responded well to the heat and humidity, which has allowed for later- planted cotton to catch up with earlier-planted cotton.

Consequently, weed pressure has increased tremendously during this time period and will need to be addressed prior to canopy closure. Successful pre applications prior to the wet period seem to still be holding, but I have seen an increase in annual grasses among others.

There will be some Palmer amaranth escapes in fields that will need to be pulled or chopped, which is part of any weed management strategy.

At this point, cotton looks good across the state and the situation is relatively quiet. Most of the cotton is ranging from early to mid-bloom, and fruit retention is high in most locations. I have had a few isolated locations experiencing low fruit retention, which is attributed to a combination of proximity to corn, excessive growth and poor drainage.

Rapid vegetative growth needs to be managed with plant growth regulators, especially given the weather pattern we have been in. It is important to be aware of the rain fastness of PGRs, insecticides and herbicides applied during a pop-up shower weather pattern similar to the one we are in now from both an economic and efficacy standpoint.

Plant bug pressure has been relatively light at this point. However, I look for this to increase in the next week or two, especially with corn maturing and peak bloom in cotton. It is after July 4, so I anticipate egg laying to begin in the next week to 10 days as well.

It is still early, and the fate of this crop is still in the hands of the weather. bkp4@msstate.edu

Keith Edmisten
Keith Edmisten
North Carolina

We often say there is no such thing as a normal growing season for cotton in North Carolina, and this year is certainly no exception.

Most of the crop is at least two weeks behind schedule due to cooler weather in May. Some of the crop is as much as six weeks behind, especially where we have had excess moisture in combination with cooler temps.

This means our effective bloom period is shorter than usual. A fairly safe assumption is that you will have enough time and heat to mature a boll if the bloom occurs by Aug. 25. It would be a good idea to go out Aug. 25 to determine on what node your crop is blooming. This might help you later in determining what bolls are worth waiting for in the fall.

A short bloom period means fruit retention is more important than a normal crop that has time to set fruit over a seven- or eight-week period. Unfortunately, late crops are also more attractive to insects. We need to make sure we don’t let our guard down in terms of scouting and timing sprays where needed.

Mepiquat applications can help with maturity, but don’t overreact and make them where conditions are not favorable for growth as they could reduce potential fruiting sites on the plant. keith_edmisten@ncsu.edu

Tyson Raper, Tennessee
Tyson Raper,

As I write this July 20, our crop remains 10 to 14 days behind. Much of the area struggled with high temperatures over the past week and only scattered rainfall. I still think yield potential for this crop is good to very good, but I’m banking on a rain within the coming week.

More plant growth regulator applications have been made in the past 10 days, but selecting rate has been difficult given our lack of rain. Retention has been good, but as our corn crop matures, we have seen increases in plant bug numbers.

Field days will obviously be much different this year than in years past. The 2020 Milan No-Till Field Day is no exception. Recordings of all tours have been completed, and the entire event will be virtual. By the time you read this, all content will be posted online.

Our Cotton Tour is likely going virtual also, but the final decision on that event has not yet been made.

I would, however, encourage you to contact your local county agent if you are interested in walking any variety trials. Most will be able to provide a plot map and give you directions to the trial locations. Walking these trials will provide the opportunity to see new cultivars in action even during the pandemic. traper@utk.edu

Calvin Meeks, Missouri
Calvin Meeks,

The Fourth of July brought us some flowering cotton here in the Missouri Bootheel. But the latest Crop Progress and Condition Report shows only 24% of the cotton is squaring, putting the crop behind the five-year average of 64%. However, we are slightly ahead of the 2019 squaring percentages. Our warm days as of late should help build heat units nicely, especially with such cool weather to start off May.

The cotton appears to have great yield potential, but I have concerns about the cool May start delaying maturity. Cotton crop conditions were rated extremely variable in the Crop Progress and Condition Report due to the issues we faced with the cool May weather.

This variability will play havoc with irrigation needs. Keep a close eye on crop growth stage on a field-by-field basis.

With the bloom period upon us, water needs will increase from an inch per week to 2 inches during the third and fourth weeks of bloom. Peak bloom will occur the last two weeks of July for fields that had blooms July 4, and water demands will taper off as we progress into August.

Cotton during this period will transition from needing 2 inches of rain per week to 1-1.5 inches during the final stages of bloom.

missouri cotton
“With the bloom period upon us, water needs will increase from an inch per week to 2 inches during the third and fourth weeks of bloom,” says Missouri cotton specialist Calvin Meeks.

Regardless, the crop is currently growing very rapidly, and a final plant growth regulator application will be needed to ensure sufficient crop earliness, especially if higher temperatures hang around. For the remainder of the season, plant bug and bollworm control should be on everyone’s minds as well as keeping an eye out for stink bugs.

Hopefully, the 2020 Missouri cotton crop will catch fall weather similar to what was observed in 2017. We had rain during August that year to help finish out the crop, followed by a warm, dry start to the fall that allowed for timely defoliation applications and harvest season. meeksc@missouri.edu

Bill Robertson, University of Arkansas
Bill Robertson,

The Prospective Plantings report by the U.S. Department of Agriculture-National Agricultural Statistics Service estimated cotton plantings in Arkansas to be 590,000 acres. The 2020 planting season was difficult on and off the farm. The Arkansas Acreage Report estimated acres at 500,000. Mid-June, our crop was running almost two weeks behind on average and with the current market situation, we must concentrate on the basics.

Tracking nodes above white flower (NAWF) from first flower to cutout (NAWF=5) can offer great insight on the crop’s condition and potential. As we approach this time of the season, we are interested in using this tool to aid in crop termination. The first fields planted are not always the first to reach cutout.

In Arkansas, the latest possible cutout dates using a 50% probability of collecting 850 heat units (HU) on a 30-plus year data set are: Aug. 9, Keiser; Aug. 14, Marianna; and Aug. 17, Rohwer. If we use the last five years’ weather data, these dates may be extended slightly (three to five days).

Establishing the cutout dates is important in identifying the last cohort or group of bolls that will contribute significantly to yield and profit. It is on this group of bolls and their development that we base our end-of-season decisions.

General termination guidelines include plant bug, cutout + 250 HU; bollworm and tobacco budworm, cutout + 350 HU; stink bug, cutout + 450 HU; fall armyworm, cutout + 500-550 HU; defoliating insects, cutout + 650 HU; harvest aid initiation, cutout + 850 HU.

As we go into August, we must continue to manage this crop in a timely fashion to maintain yield potential while keeping expenses in check. For more information on crop termination, contact your local county Extension agent. brobertson@uaex.edu

ben mcknight
Ben McKnight
Texas A&M

Growers in the Lower Rio Grande Valley and Coastal Bend will soon be gearing up for the approaching harvest. Much of the early planted cotton in these regions is heavy with open, cracked bolls. As of this writing July 10, first shots of defoliants will be applied on the early planted cotton in these areas in the coming week or weeks.

After a very dry start to the season, expectations for the crop in the Coastal Bend are drastically different than what was expected much earlier in the season. Abundant, timely rains fell in this area, and many are talking of exceptional yields this year.

The condition of the cotton crop along the Upper Gulf Coast is also promising, and most of the acreage in this region is at cutout. The area experienced a large moth flight in June. Timely scouting and management decisions in susceptible varieties aided growers in minimizing damage from the pests.

It has been a dry start to July in Southeast Texas following periods of heavy rain and an extended period of cloudy weather in late June. A significant amount of fruit shed was observed in this region following nearly a week of overcast skies. High temperatures are projected to be more than 100 degrees Fahrenheit with dry conditions in the coming days. Irrigated acres will receive another shot of water. Most of the crop in this region is at 6-7 NAWF.

The Blacklands has also been dry, and another round of rainfall is greatly needed. Without another substantial rain soon, cotton will be approaching cutout on the dryland acres in this area.

Rainfall in the Rolling Plains at the beginning of July helped cotton that had emerged following a hot June. The condition of irrigated acres in the Rolling Plains looks good as of the first weeks of July, and many fields have squaring cotton. bmcknight@tamu.edu

Murilo Maeda
Murilo Maeda
Texas A&M

Early cotton season in the Texas High Plains has been challenging, mostly because of moisture (or lack thereof). It is unbelievable to think July is already gone. All things considered, though, this may (or may not) be quick enough!

Generally speaking, most of West Texas remains dry, with only limited spots receiving any recent rainfall. Moisture came too late to do any good for our dryland, but it will certainly help out in keeping the irrigated crop going.

As I write this in mid-July, dryland cotton is scattered across the region and good-looking fields are few and far between. Irrigated acres that escaped blowing dust and hail early on look to be in great shape overall and may be running a few days to a few weeks late.

While it may be fair to attribute the late start to the widespread lack of moisture during planting, it is worth noting that in many cases even irrigated fields (where water is limited) have struggled to get a good stand this year. Yes, it’s truly been that hot and dry.

Looking through the end of July, weather forecast indicates high temperatures will be hovering around 100 degrees Fahrenheit with virtually no precipitation in sight. As we begin the crop’s reproductive phase, that forecast is far from ideal. From here on out, our attention has to be on high square retention, so keep an eye on possible sources of stress.

From a management standpoint, input timeliness is crucial moving forward. Managing the crop for earliness (e.g. growth regulators, fertility and irrigation) can minimize potential negative effects of an early freeze. With all the uncertainties of 2020 thus far, it is important to set realistic expectations. If I may give you one piece of advice this year, avoid trying to push your crop too hard if you had a late start. mmaeda@ag.tamu.edu

Randy Norton
Randy Norton

With most of the 2020 crop on the back side of peak bloom, decisions will soon be made regarding terminating the crop and preparing for harvest. The 2020 situation at this stage of the season is significantly better than where we were one year ago.

Heat unit accumulations are much more in line with normal, and the fruit load on most of the crop looks good.

Research plot assessments across the state indicate above-average fruit retention going into the final weeks of the growing season. Insect pressure up to this point in the season has been minimal, and beneficial/predator populations have continued to help keep insect pests at bay.

One area of concern is the growing populations of glyphosate-resistant pigweed seen in fields across the state. Since the first glyphosate-resistant pigweed was discovered in Arizona in 2012, they have spread to all cotton-producing regions of the state.

Use of alternate chemistries, residual chemistries and crop rotation are among some of the strategies to assist in combating this problem in our cotton fields.

I am optimistic about the prospects for the 2020 crop, if we can continue into late summer and early fall with optimum conditions for finishing it out. rnorton@cals.arizona.edu

Bob Hutmacher
Bob Hutmacher

Available irrigation water allocations have been reduced significantly in most valley irrigation districts, and growers may be making hard decisions about when and where to use water on their farms. August is typically when the final irrigation of the growing season is applied in many cotton fields, particularly in water-short years.

This will still be true in many of the earlier-planted (March through mid-April) fields this year. But growers with sandy loam soils or late-planted fields might end up considering final irrigation in September. Where limited water and late-season water costs are concerns, it will be important to decide:

• How long you need to maintain plants in a non-stressed or better than mildly-stressed condition.

• How much of the later-developing bolls or “top crop” you can afford to mature out.
Managed water stress levels have a definite place in crop management. But during the critical flowering and fruit setting period, you still need to avoid severe stress that could damage flower set and early boll retention. This is the vital “window” to set fruit and avoid having to extend the crop way Into the fall to go after a late top crop.

For growers using leaf water potential (LWP) measurements in Pima cotton, our research suggests avoiding LWP values greater than about -21 to -22 bars during flowering and early boll set. This applies if you are using a stress management (bloom-it-to-the-top) approach in scheduling irrigations (about -19 to -20 bars in Upland varieties).

If you don’t use LWP measurements, here is a general guideline. During the four- to five-week period following first bloom while you are trying to set a lot of bolls, don’t allow extended periods where the plants have visibly wilted leaves during all or most of the hotter afternoon hours.

Significant wilting means little evaporative cooling and little photosynthesis will be occurring during those hours.

These processes are needed for plants to be productive. This is especially true if there are extended periods with daily high temps in the 103-110-plus Fahrenheit range. In addition, more severe water stress during the four- to five-plus-week period following first bloom tends to risk square and flower loss and even cavitation of small bolls.

If water remains limiting, higher levels of plant water stress (LWP of -23 to -25 bars in Pima, -21 to -23 bars in Upland) can be tolerated during boll maturation after cutout with less impact on fruit retention or fiber quality.

LWP target values can be somewhat different if you are using drip irrigation (sometimes 1.5 to 2 bars lower), so contact your University of California Cooperative Extension adviser or specialist if you’d like to have some additional discussion about that subject.

If late-season water supplies are limited or costly, it is more important than ever to assess the top crop for additional yield potential.

Decide if it represents cotton of adequate value to warrant costs for that last irrigation. Much of the primary fiber development affecting length and strength takes place in critical periods of about the first three-plus weeks after each flower blooms.

Negative effects of stress on fiber quality will be much less if severe water stress is avoided through about five weeks after that flower blooms. Making the best crop under limited water situations requires good knowledge of where and when bolls were set on your crop to assess likely impacts of water stress severity and timing. rbhutmacher@ucdavis.edu

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