2021 Cotton Crop Update

David Wright, Florida
David Wright,

August is a key month to finish off the cotton crop. Most of the crop management (fertilization, herbicides) is through, and it is important to protect the fruit from stinkbugs and plant bugs. We had a wet July, which allowed the crop to make excellent growth.

In some places, the plants were too tall as wet soils stopped growers from getting across the field to apply growth regulators. Most of the sidedress nitrogen goes out in late June or July, and cotton petiole nitrate continues to goes down as a normal occurrence in August.

Late N applications (after the third week of bloom) does not result in yield increases and often decreases yield as plants continue with new growth, making the crop harder to defoliate.

Irrigation needs are less in late August and should be adjusted as bolls begin to open at the bottom of the canopy. Many of the new varieties have three Bt genes and set fruit earlier due to insect protection. We often debate whether to harvest early or a little later for best yields.

But the best time to harvest is to have open bolls and good weather to coincide. However, none of us knows when that will be, so keeping on a normal schedule is the best we can do in most years. wright@ufl.edu

camp hand
Camp Hand,

As one of the newest specialists at the University of Georgia and in the cotton specialist group, I am still learning. One thing that I have been trying to do lately is spend time every week with some of the best county agents in the country and see what the crop looks like across the state (this has been my favorite part of my job so far).

Based on what I have seen over the past few weeks, I would say the Georgia crop looks great. Of course, there have been some fields I have visited where the grower says to the county agent, “Don’t take him there, that’s some of our worst cotton.” And after looking at it.

I tell them I think the field looks really good! Meanwhile, I have Dr. Phillip Roberts ride with me to my studies on the station where I think there is an issue. After examining the field, he says, “Oh you’ll be fine, this cotton will still make 3 bales.” He’s been at this a whole lot longer than I have, so I trust his judgment.

At the time this is published, the majority of our crop should be right around peak bloom. In general, plant growth regulator applications should be winding down. Keep in mind, the bigger the plant gets, a higher rate might be necessary to manage growth. We also need to have boots on the ground scouting insects (stink bugs and silverleaf whiteflies) and foliar diseases (target spot and areolate mildew).

If there are any questions, reach out to your local UGA county Extension agent. They, along with myself and the other specialists, are here to help! camphand@uga.edu

Keith Edmisten
Keith Edmisten,
North Carolina

August is normally a laxer time for cotton growers agronomically speaking. For the most part, we should have finished sidedressing nitrogen applications as well as plant growth regulator applications. God realized this and gave us insects to keep us on our toes in August.

The crop is late overall, and protecting fruit from insects is more important with late crops. Cotton is great at compensating for some levels of fruit loss, but a late crop may not allow for a lot of compensation.

Insects should be our focus in this month although there are always people promoting late growth regulator applications. We have several years of research and have seen no benefit to growth regulators after the second to third week of bloom.

It would be a good idea to go out and tag some blooms around Aug. 20. Doing this can give you an idea of what bolls may be worth waiting for when we get to defoliation time.

Blooms after Aug. 20 are less likely to result in harvestable bolls than earlier blooms. This is also a good time to evaluate your varieties in terms of desired stalk height and row closure on your soils. keith_edmisten@ncsu.edu

Tyson Raper, Tennessee
Tyson Raper,

As I write this July 13, blooms are just now becoming a little easier to find in Tennessee. It may still be another five days before the average field reaches the first week of bloom.

Many of the conversations I’ve had of late tend to migrate toward last effective bloom date and its proximity in time to us. As you likely recall, last effective bloom date is calculated as the date in which the probability of a new flower developing into a harvestable boll drops below 50%.

We calculate that date with historical weather data and the assumption that a flower will require 750 to 850 heat units to mature. This date is particularly important since it can help us identify the last harvestable fruiting position and understand when we may begin terminating insecticide applications.

Usually, we reach the last effective bloom date with a minimum of four good weeks of bloom. This year, it appears some fields may reach last effective bloom date with less than three weeks of bloom. This sets us up for a difficult decision. We can either accept the short flowering window and stop protecting fruit that flower after our last effective bloom date OR accept a higher level of risk by continuing to protect fruit that flower after our last effective bloom date to potentially recoup lost time.

As we move deeper into August, check our blog (news.utcrops.com) for a refresher on insecticide termination guidelines and for more information on last effective bloom date. traper@utk.edu

STEVE BROWN, alabama
Steve M. Brown,

I had a garden this year. In fact, I participated in multiple gardens, three small and one large. One in particular comprised a few rows in a very, very prominent and shared spot alongside my university peers. When I planted my four rows of green beans, I knew my reputation was on the line.

Most cotton producers have a field or two in a highly noticeable spot, or at least one they see every day, multiple times a day. Maybe the presence and prominence of that field(s) puts the farmer’s reputation on the line, so to speak. The field can provide a great sense of satisfaction or something less.

I always chuckle (to myself, of course) that it seems that screw ups often happen in these exact fields. That visible, prominent field could possibly be more than a “show-off” plot.

Maybe it could be considered a “show-me” field, one in which the grower proves to himself just how efficient he can be, how much cotton he can make with his most careful, timely management. Soil scientist talk about the “4 Rs” —right source, right rate, right time and right place. That’s the spirit of such an effort.

August is the home stretch in the Southeast. We’re dealing with stink bugs, finishing with plant growth regulators, maybe adding a final foliar fertilizer, and, if possible, supplying irrigation. In regard to all these inputs, doing the right thing at the right time maximizes potential.

Given the rains in June and July and the relatively moderate temperatures, a good August just might push us to a record yield. We’ve got a ways to go, but this crop’s prospects look strong. cottonbrown@auburn.edu

brian pieralisi
Brian Pieralisi,

Mississippi cotton growers have experienced challenges since the beginning of planting season. We have dealt with extremes from cool, wet weather early to excessive rainfall and backwater flooding.

These conditions have plagued cotton from late April through the middle of June. As a result, many of our cotton acres have a poorly developed root system, small stature and are a couple weeks behind in maturity. A combination of these setbacks have only confounded management strategies as we move into the reproductive stages.

Plant bugs are increasing across the state, requiring many repeat insecticidal applications — in some cases three to five days apart to manage the adult pest. Multiple trips across the field have allowed growers to fine tune their plant growth regulator management strategies.

This year, cotton growth is highly variable from farm to farm, field to field, and even within fields. I have reports of cotton not growing the way it normally does, which is likely due to a poor root system from the prolonged early wet weather, compounded with plant bug induced poor square retention. Depending on variety and vegetative potential, the eight- to 12-node PGR application has been left out or applied only to vigorously growing cotton.

Some farmers are applying variable-rate PGRs based on zones where rates range from zero, medium and high (relatively speaking). Also, multiple trips have allowed cotton growers to “spoon feed” PGRs to keep plants growing vertically.

As I write this, most of our cotton ranges from early squaring to mid-bloom. Daylight hours are getting shorter for younger cotton, and its success will depend on the fall we experiene. Since all of the cards for this crop haven’t been played yet, I remain optimistic we can still make a crop! bkp4@msstate.edu

matt foster
Matt Foster,

As I write this July 13, about 80% of the cotton crop is squaring and 30% is setting bolls, which is behind the five-year average of 90% and 50%, respectively. This growth stage variability is due to high rainfall received in April, May and into June. Planting dates ranged from early April to the third week of June.

June planted cotton is growing off fast and is about a node above last year’s crop at this point in the growing season. Square retention was good as we approached first bloom.

Irrigation started in some areas of the state during the latter part of June. Despite unfavorable weather conditions encountered early on, most of the cotton crop throughout the state looks good.

For the remainder of the season, growers and consultants will focus on plant bug and bollworm control. Insect pressure from plant bugs has been high in June and July, and bollworm numbers are starting to increase.

Currently, mepiquat chloride applications are being made to manage plant height. Variability in planting dates, excessive rainfall and heavy plant bug pressure has made the 2021 cotton crop extremely variable. But I am optimistic we will have a good crop this year. mfoster@agcenter.lsu.edu

Bill Robertson, University of Arkansas
Bill Robertson,

In mid-July, our crop is currently 10 days to two weeks behind. A big part of the delay is a result of the record-breaking cold temperatures experienced during Memorial Day weekend.

Tracking nodes above white flower 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 use the 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 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 dates of cutout is important in identifying the last cohort or group of bolls that will contribute significantly to yield and profit. It is 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.

Going into August, we must continue to manage this crop in a timely fashion to maintain yield and quality potential. For more on crop termination, contact your local county Extension Agent. brobertson@uaex.edu

seth byrd
Seth Byrd,

As of mid-July, the cotton crop for much of Oklahoma has fared well. There have been pest concerns as of late, namely fleahoppers and even some plant bug issues, but the majority of the crop will be well into bloom by the time this issue of Cotton Farming reaches you.

Although weather systems bringing rain to the state haven’t been as frequent, we’ve been able to make it to July with fairly minimal heat and water stress for much of the crop.

With the early moisture much of the crop received and continues to get intermittently, there will likely be plant growth regulator applications occurring on a large number of acres during July and potentially through August, even for the most conservative PGR users, like myself.

This is particularly true for irrigated cotton. Keep in mind variety growth and maturity characteristics, as well as the traditionally recommended measurements or factors, such as internode length between the fourth and fifth internode, forecast, soil type, NAWF and fruit retention.

For more information on PGRs in cotton, refer to our factsheet at https://bit.ly/2VUFCH7. seth.byrd@okstate.edu

ben mcknight
Ben McKnight,
Texas A&M

As of mid-July, wet conditions prevail for most of Texas. Rainfall, in some cases abundant, continued throughout most of the state last month. Most cotton in the Lower Rio Grande Valley is at cutout or quickly approaching.

In the Coastal Bend, cotton that had recovered from extremely saturated conditions in previous months was met with another round of heavy rainfall in early July. Delayed maturity can be expected in areas that remained flooded or saturated for extended periods of time.

Reports indicate that with the current crop condition, yields may be slightly above average for this region.

Cotton in the Upper Gulf Coast is progressing nicely following recovery from saturated conditions. Fields that did not drain uniformly following inundation were left with plant uniformity issues when conditions improved, especially in low spots. While not completely caught up with cotton plants in higher areas, the crop looks much better.

Most of the crop in the Upper Gulf Coast is at six- to nine-NAWF. In the Blackland Prairie, conditions are wet in some areas, making PGR applications difficult. Cotton in this region looks better than it did in the previous two months and has started to bloom.

Rainy conditions hindered timely herbicide applications, but growers took advantage of gaps in the rainfall, and weed control has improved compared to May and early June.

The Rolling Plains experienced warm, dry conditions in mid- to late June, but rainfall in early July has the crop looking good. Wet conditions have made timely herbicide applications difficult, and recent rainfall has brought on another flush of weeds.

Some of the later planted fields in this region have cotton with only a few true leaves while earlier planted fields have six to eight leaves. bmcknight@tamu.edu

Murilo Maeda
Murilo Maeda,
Texas A&M

As I write this the first half of July, much of the cotton across West Texas looks good. Due to delays during planting season mostly related to excessive rainfall, we currently have quite the spread in crop stages. Irrigated fields are just beginning to bloom and dryland cotton is at four to five leaf with everything in between.

While we have missed a few acres due to the cool and wet start north into the Texas Panhandle, we have a lot of good-looking dryland acres this year, especially in areas south of Lubbock.

We have had reports of hail damage throughout the region the latter part of June and early July, ranging from minimal to complete field loss. These storms seem to have been more isolated than widespread with only a few reports of complete wipeouts. Rainfall has been timely in recent weeks, and we are well positioned to make a good crop this year.

A main concern will be overall crop maturity going into the fall. While we may be OK if it turns hot and dry from here on out, a few more rains and cooler weather may have us a little short on time to finish the season.

Generally speaking, weather has been rather on the cool side compared to what we usually expect this time of year. With all things considered, I am always told the weather around here can quickly change. Just make sure you have a plan A and B, depending on what the weather decides to do. mmaeda@ag.tamu.edu

Randy Norton
Randy Norton

The cotton crop in Arizona is in varying stages of development. As of this writing, we have cotton in the southwestern part of the state that is heading quickly toward cut-out. As I walked plots and other production fields in the area recently, the crop looks to be in very good shape.

The intense heat experienced throughout mid-June had an impact on the crop, and evidence of small boll shed due to these events was clear. Despite the heat-induced fruit shed, fruit retention in general was still in the mid-70% range for everything I evaluated.

For this time of year and for the growth stage of the crop, it is in very good shape. Final irrigation decisions will be made soon, if not already made at the time this writing. I am optimistic about the crop in that part of the state.

Central and eastern Arizona are similar in their growth stage with most of the crop at the time of this writing heading full steam into peak bloom. The heat experienced in mid-June appeared to have only a minimal effect on the crop as it was in the very early stages of bloom while a good portion of the crop had not even begun blooming yet.

The heat stress we are currently experiencing will have a much larger affect. Monitoring the crop for excessive fruit shed will be critical to successful management of the vegetative reproductive balance. Be prepared to slow down vegetative growth with healthy doses of plant growth regulator.

Insect pressure has generally been light so far. Most of the fruit shed you observe will likely be due to environmental stressors such as heat and/or moisture stress. Monitoring crop growth and development can be achieved through simple plant mapping on a regular basis to determine where the crop is with respect to normal as it relates to fruit retention, height-to-node ratios, and nodes above white flower.

For more information on this topic and others related to cotton crop management, go to cals.arizona.edu/crops. rnorton@cals.arizona.edu

Bob Hutmacher
Bob Hutmacher,

In a typical year for San Joaquin Valley cotton, most fruit is set during late June through early August flowering. August is typically when the final irrigation is applied in most fields.

With irrigation water supply limits this year, this may still be true in many March- and April-planted fields. In sandy loam soils or late-planted fields or fields that had fruit losses due to high heat stress periods, growers may consider final irrigations that extend into 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.
With the potential for sporadic hot weather to affect fruit set, it will be important to assess boll distribution sometime in August.

In mid-July, some fields had good early and mid-canopy fruit retention but showed signs of reduced vigor (declining height:node ratios and NAWF) and may not end up with a large, late-developing top crop unless you push them with water and nutrients this month.

Where yields were reduced by earlier heat or water stress and you want to push for later bolls, or in fields where continued boll set is strong right through August, you may not want to sacrifice significant top crops.

In a year like this, there may be good yields out there for growers who properly assess developing boll loads mid- and late August and adjust water applications to fill out later-developing bolls. rbhutmacher@ucdavis.edfrui

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