Monday, November 28, 2022

Prepare For Early Season Pests

ARIZONA | Randy Norton

Randy Norton
Randy Norton
Arizona

Nearly all the 2022 crop is in the ground with some of the earliest planted cotton in the western reaches of the state nearing first bloom. However, most of the crop across Arizona is not even to first square yet. 

Managing very young cotton is critical to the eventual success of your crop. There are many potential pests that can affect early season cotton both seen, such as thrips, flea beetle, etc. and unseen, such as nematodes. Knowing your fields and scouting for early season pests is critical to maintaining a healthy and vigorous crop. Often, a limited amount of early season insect pressure can be sustained without jeopardizing production. However, higher levels of sustained infestation can lead to reduced leaf surface area, split (forked) terminals and generally unhealthy seedlings. 

New technology on the verge of large-scale commercial release will help to manage some of these early season pests (specifically thrips). Knowing your field and the soil before planting and taking appropriate management actions will help you manage the unseen pests, such as nematodes. Let’s also not forget about proper early season crop management from an agronomic perspective. A hot and dry spring and early summer winds can quickly desiccate the soil and lead to water-stressed young plants. 

Proper irrigation management early in the season is critical. This type of stress can result in aborted early season fruit set, increased vegetative growth potential and delays in maturity, among a variety of other management complications. Maintaining a healthy young crop from an agronomic perspective will also make the crop better able to withstand other stresses, such as insect and disease pressure. Information related to these topics, along with many others, can be found on our UArizona website at extension.arizona.edu/crops-soils. rnorton@cals.arizona.edu

TEXAS | Murilo Maeda

Murilo Maeda
Murilo Maeda,
Texas A&M

Planting is right around the corner by the time you receive this issue of Cotton Farming. As of April 8, conditions in the Texas High Plains have not improved much since I last wrote to you. In fact, most of our region has been “upgraded” to extreme and/or exceptional drought on the last drought monitor released on April 7. While the northern High Plains saw a little moisture and some snow, mostly dry conditions are prevalent there as well. At the time of this writing, I see warm weather and some very windy days in the short-term forecast; however, we will continue hoping for enough moisture to allow planting, and subsequent rains to carry us through the season. 

I mentioned last month about requesting warm/cool germination from your seed retailer as you commit to purchasing seed. Even though moisture is still the strongest limiting factor for seed germination and initial crop establishment at the field level, having this information can help you gauge the overall quality of the seed you are purchasing. That, in turn, can help you decide when to plant variety A versus variety B, for example. A recent survey conducted by Extension cotton specialists across the nation indicated that all samples testing below 80% warm germination also tested below 70% in cool germination. The cool germination test is known to be quite variable, but a good rule of thumb is the higher those numbers are, the better. 

While on their own they will not guarantee an adequate stand of cotton, the vigor index (warm + cool germination) can help guide your planting decisions. Simply add the warm and cool germination values you obtained for your seed. If the resulting number is below 120, that seed would be classified as having a poor vigor index. Between 140 and 159 is considered good, and 160 or greater would be classified as excellent. Faced with challenging conditions at planting, starting with higher vigor index seed will help ensure you are giving your crop the better chance. Wishing you all a successful 2022 season! mmaeda@ag.tamu.edu 

TEXAS | Ben McKnight

ben mcknight
Ben McKnight,
Texas A&M

As of the first week of April, not much has changed from last month regarding any substantial relief from dry conditions across the state. Cotton in the Lower Rio Grande Valley and Coastal Bend has emerged if it was planted into moisture. With a dry weather forecast for the coming weeks, any remaining cotton that hasn’t been planted in the Coastal Bend will be dry planted ahead of the insurance cutoff date. Growers in the Upper Gulf Coast have made great progress getting the crop planted thus far, and soil moisture conditions in this region are better than much of the state south of Interstate 10. 

A good friend once told me the highest yield potential a cotton plant will ever have throughout the entire life cycle is when it’s a seed. As soon as that seed is planted into the seedbed, the clock starts ticking and management decisions must be made to preserve as much yield as possible. From a weed competition standpoint, nothing could be more accurate. In the late 1960s, Gail Buchanan and Earl Burns conducted trials in Alabama evaluating weed competition in cotton. The results from their work highlight the importance of keeping a cotton crop weed free for the first eight weeks following emergence to maximize yield. 

As a weed scientist by training, I am a big fan of starting clean and staying clean. Residual herbicides, when used according to label recommendations, can provide tremendous value to weed control efforts on the front end of the season. By reducing early season weed competition with an effective preemergence herbicide program, we are accomplishing two very important goals toward enhancing productivity. First, we are reducing the pressure put on postemergence products applied later in the season, which is an important component to an overall herbicide resistance management program. Secondly, effective early season weed control will reduce yield-robbing competition in the most critical time of the season to maintain a weed-free environment for cotton plants. 

Keep in mind to always check the herbicide label on residual products for important information including rates, crop rotation intervals and moisture requirements for product activation. Additionally, a great resource available for all weed management topics in Texas cotton can be found at https://bit.ly/3JN2ueS. bmcknight@tamu.edu 

OKLAHOMA | Seth Byrd

seth byrd
Seth Byrd,
Oklahoma

As I write this in mid-April, most of the cotton producing areas of Oklahoma are still in need of rain to raise hopes as we creep closer to planting the 2022 crop. While rain is something we can’t control, by and large, pest issues are something we can. There are a variety of ways to address potential pest issues. While diseases are largely mitigated through the use of seed treatments and variety selection (although that doesn’t alleviate all diseases as we’ve experienced in previous years), there are a variety of strategies that can be used to address weeds and insects.

The vast majority of cotton planted across the U.S. Cotton Belt contains a trait that provides auxin resistance, and Oklahoma is no exception.
Although as we all know, these chemistries, much less the traits themselves, have not completely solved weed issues. I’d argue that in many cases it may have made them worse in the long run, but that’s a conversation for another day. A solid pre-emergence program, post-emergent use of residuals and rotating MOAs are all solid methods to address weed issues through chemical means. These are certainly not new approaches, and if you’ve heard a cotton weed science discussion in the last decade, all these are typically discussed as priorities when developing a herbicide program. Tillage or cover crops are other mechanical or cultural methods for suppressing weeds — likely used as an either/or approach. But these two methods could be combined in some systems. The key is to limit the number of weeds that emerge by any means necessary. Whatever method works best for you in achieving that should be the one to go with, as long as it also makes financial sense.

Like seedling disease, we can generally use seed treatments to address early season insect concerns. In Oklahoma, this is typically going to be thrips. Many acres are planted to seed with only a base (fungicide only) seed treatment, leaving them vulnerable to thrip damage. Last year, this not only triggered more oversprays of insecticides due to slow growing conditions but also revealed wire worm infestations in some areas, which resulted in significant stand loss and replants. Insecticide seed treatments can at least mitigate these issues if that option is elected, but in-furrow or oversprays may still be necessary for thrips. For mid-season pests such as plant bugs, flea hoppers and stink bugs that are not addressed by Bt traits, consistent scouting is required to ensure yield-limiting infestations don’t go unaddressed. seth.byrd@okstate.edu

LOUISIANA | Matt Foster

matt foster
Matt Foster,
Louisiana

According to the USDA National Agricultural Statistics Service, cotton acreage intentions in Louisiana are at 200,000 acres, up 82% from the 110,000 acres planted last year. As I write this April 10, substantial rainfall is predicted for most cotton producing areas in the state as the optimal planting window approaches. Cotton planting should begin soon, depending on field conditions. 

Once stands have been established, nitrogen applications are made for the upcoming season. Recommended N rates are 60-90 lbs/ac for coarse-textured soils and 90-120 lbs/ac for finer-textured soils. The lower recommended rates should be used on fields following soybean, corn or legume cover crops or fields with a history of excessive stalk growth. Do not apply excess N that can produce very tall and rank cotton. Increased vegetative growth will hinder reproductive growth and, ultimately, yield. To limit excessive growth, producers will have to rely heavily on mepiquat chloride applications, which can potentially make defoliation difficult at the end of the season. 

Best management practices suggest making split applications of N on sandy soils with high leaching potential or soils with a high saturation potential because of denitrification losses. For split N applications, one-third to one-half should be applied at planting with the remainder applied by early bloom at the latest. 

Also, after crop emergence, producers should concentrate on managing the cotton plant from the first- through fifth-leaf stage. Reaching the fifth true leaf stage with minimal damage from thrips is a key factor in producing good cotton yields. Seed treatments for controlling early season insect pests play a valuable role in getting the cotton plant off to a rapid start. Depending on environmental conditions, seed treatments may last anywhere from 14-28 days. Oftentimes, under cool spring temperatures, reaching the fifth true leaf stage is delayed and seed treatments may lose their effectiveness. Under these conditions, foliar sprays may be needed. Automatic or convenience applications should be avoided if economic thresholds haven’t been reached. Best of luck during the upcoming season. mfoster@agcenter.lsu.edu

ARKANSAS |Bill Robertson

Bill Robertson, University of Arkansas
Bill Robertson,
Arkansas

The Prospective Plantings report released in March by USDA-NASS estimated cotton planting intentions at 520,000 acres, up 8% from the 480,000 acres planted last year. This estimate is in line with the NCC estimate released earlier this year.

In our recent crop budget revisions, we see input costs for cotton increasing close to 40%. It is even more critical to do things right the first time. Oftentimes, we feel the need to plant as early as possible. The last two years have demonstrated that we can still optimize yields with delays in planting. When planting into cold soils, it is imperative to use the highest quality seed. As seed size decreases, seed quality becomes more critical when planting in marginal conditions.

When determining if replanting is necessary, many factors should be considered. First, it is important to evaluate the current stand of plants that will survive. Establishing the occurrence of skips greater than three feet in length — especially when this occurs simultaneously in adjacent rows — is critical. The ability of cotton to adapt and maintain yield potential at lower plant populations is often underestimated. If the decision to replant is difficult, it is usually best to keep it.

The period from planting to first square is a critical time for the cotton plant. While water and nutritional requirements for the plant are low, cotton is not a very good competitor. Allowing weeds or other pests to overcome pre-squaring cotton will impact yield potential. It is easy to sometimes overlook the importance of early season weed control when we have the tools to clean up a weedy mess down the road. brobertson@uada.edu

MISSISSIPPI | Brian Pieralisi

brian pieralisi
Brian Pieralisi,
Mississippi

Cotton acres in Mississippi are expected to increase 11% from last year. With an increase in both acres and cotton prices, one can bet an abundance of early season pests will try to cause problems for seedling cotton. Planting season was unusually tough last year due to excessive cool, wet weather throughout May. As I write this, the 2022 planting season remains untarnished with hopeful expectations of planting during the optimal window of May 1-10. Growers should focus on management tactics within their control and take advantage of any favorable planting opportunities.

Thrips are the primary early season pest affecting Mississippi cotton. Over the past several years, thrip pressure has been unusually high, causing multiple applications in some cases. This can likely be attributed to slow growing cotton, met with environmental conditions favorable for this pest. Typically, by the three- to four-leaf stage, cotton plants are past the most susceptible stage for economic injury or delays in maturity. However, a sound management plan is in order to mitigate injuries from thrips. 

Early season thrip management typically consists of imidacloprid-treated seed or in-furrow treatments, followed by foliar applications. In-furrow treatments of 1.1 lbs. acephate, or 8 oz. imidacloprid, should be directed on or below the seed for most effective control. Under high reniform nematode populations, 3.5-5 lbs. aldicarb is another option. Most current cotton varieties are pretreated with recommended fungicides; however, using in-furrow insecticides increases susceptibility to cotton seedling diseases. Be sure to plant seeds treated with a recommended fungicide.

Lastly, most cotton grown in Mississippi is conventionally tilled and cutworms are not an issue. However, with an increase in both cover-cropped and no-till acres, cutworms could establish on existing vegetation. Cover crops should be terminated at least three weeks prior to planting to avoid risks associated with stand reduction. If vegetation is not terminated three weeks prior to planting, a pyrethroid should be used at planting time, which will protect early season cotton seedlings from stand reductions. bkp4@msstate.edu

TENNESSEE | Tyson Raper

Tyson Raper, Tennessee
Tyson Raper,
Tennessee

In my opinion, the 2022 season represents a high risk, high reward scenario. My colleagues and I have spent the winter months talking about decisions that minimize risk and increase your likelihood for remaining profitable in 2022. When boiled down, the three most important decisions to make right now are seeding rates, residual herbicides and nitrogen rate. 

Data collected through the Mid-South suggests we may be able to reduce seeding rates. Planting too thick will likely not increase yields but will increase your financial risk by more than just the cost of seed. Stands that are too thick have the potential to delay maturity, increase the need for plant growth regulators and decrease penetration of foliar-applied inputs like insecticides or defoliants. 

Second, residuals are key for 2022, and you should plan to overlay them to minimize reliance on other products that may be difficult to find. Finally, properly select your nitrogen rate and be sure not to over apply. I’d carefully consider a substantial reduction in nitrogen during 2022 since an over-application of N often increases the need for so many other inputs. As we move into planting, I encourage you to reach out to your agronomist to make sure you’ve optimized each of these numbers. traper@utk.edu

NORTH CAROLINA | Guy Collins

Guy Collins, North Carolina
Guy Collins,
North Carolina

As I write this April 4, there’s no way to know what the weather will be during planting season. It’s hard enough to assess the weather forecasts even within a few days during this time of the season. Every year seems to be different but challenging in its own way.  

Planting will likely be underway by the time this article is published. We’ve harped on the importance of having seed tested by NCDA quite a bit, so hopefully most growers have used that resource to know the warm and cool germ of seed they purchased and use it to make better planting decisions. The Cotton Planting Conditions Calculator can be found on the NCSU Cotton Portal website (https://cotton.ces.ncsu.edu/) under “Calculators and Decision Aids” or directly at https://products.climate.ncsu.edu/ag/cotton-planting/. 

We encourage growers to check this calculator every morning and every evening during planting season. It uses National Weather Service forecasts and provides a real-time assessment and rating of the five-day forecasted planting conditions for cotton. The calculator applies both predicted temperatures and heat unit accumulation, as well as the likelihood of rainfall. Checking it every morning and evening will allow growers to see how subtle changes in weather forecasts may affect the rating for planting conditions. This is especially true during periods when conditions are less than ideal but are still acceptable — or when the predicted heat unit accumulation is right on the cusp of one category versus another. Using this resource, along with knowing the warm and cool germ of seed, will help you navigate through planting season with the best decisions possible.  

Last year illustrated the importance of proper planting depth. As the planting season progressed, our top soils got drier, which in turn, encouraged growers to plant deeper in order to “chase” moisture. For cotton, this is a mistake that often leads to poor stands and necessitates replanting.  Most of our cotton is grown in strip-till or no-till systems without a bed.  Needless to say, soils remain cooler than cotton grown on beds. When chasing moisture by planting deeper, we actually cause more stress on cotton seedlings by prolonging the time and energy required for emergence and potentially placing seed in cooler soil zones. In these situations, moisture is already limited, therefore what moisture remains may be enough to sprout the seed but not enough for it to emerge. To compound matters further, any badly needed rain is likely to cause crusting in many of our Coastal Plains’ soils, which further exacerbates the problem. Planting cotton at a ½-inch deep (or the minimal depth required for soil coverage) in completely dry soil may require waiting on a rain. But in nearly all cases, it results in much better stands once rains return and is less likely to necessitate replanting. guy_collins@ncsu.edu

GEORGIA | Camp Hand

camp hand
Camp Hand,
Georgia

As I write this April 12, it is a beautiful, sunny afternoon in Tifton. I think I might plant some cotton tomorrow, but I hope that if you are a grower in Georgia reading this that you waited longer than me. I can’t wait any longer!

In my last rendition of Specialist’s Speaking, I addressed starting the season on the right foot in terms of seeding rates. One major way we can make sure we start the season off right is by managing early season pests. I mentioned in the latest UGA Cotton Team Newsletter I have been thinking a lot this year that we need to control the things we can control. How do we do that in terms of early season pests? 

First thing for me is weed management. We can’t control the product shortages that folks have been talking about for months, but we can control what we do at planting. Putting residuals behind the planter is a way for us to control the things we can control. It buys us time, gets the crop off to a good start and allows us to use other inputs as efficiently as possible. The second thing is thrips. Dr. Roberts tells me these are one of the most consistent pests we face, and they can cost a grower a half a bale of cotton. At-plant insecticides, coupled with a seed treatment, are an easy way to protect your crop and allow yourself that good start. Lastly, are nematodes. Dr. Kemerait tells me that once the furrow is closed, you watch from the sidelines in terms of nematodes. If they are a problem in your field, let’s make sure to handle that by using a nematicide or planting a resistant variety. The last thing we want to do is hinder our crop right out of the gate and not use our inputs efficiently. 

One last thought: Dr. Glen Harris and I have talked a lot about fertility this year, particularly as it relates to nitrogen. Pre-plant nitrogen is one thing that would be easy to cut, but I wouldn’t go with nothing up front. It scares me to do that because of what happened last year (delayed sidedress because of rain). What if we can’t be timely with a sidedress application? Once you’re behind, it’s hard to catch up. 

Although inputs are high, the cotton price is high, too. Let’s set the crop up to be successful early, and we’ll be in good shape. Your local UGA county Extension agent and specialists are here to help! Reach out if you have any questions. camphand@uga.edu 

FLORIDA | David Wright

David Wright, Florida
David Wright,
Florida

May is the key month for cotton growers in establishing stands and protecting the tender plants from pests. April is often too wet or cold, while May tends to be dry. In the past few years, growers have had dry weather conditions to contend with at planting into May. 

A target of killing cover crops four to five weeks in advance of planting is a good idea for moisture conservation, as well as reduction in insect pests that could damage young cotton seedlings. Many growers strip rows off several weeks ahead of planting to spread the workload and to allow a smaller tractor with planters to come in for the planting operation. All of these can work to ensure that new weed growth does not occur between time of killing cover crops and planting, or strip tilling and planting. 

Generally, 2,4-D-type materials applied five weeks ahead of planting will kill many of the broadleaf weeds that may be harder to control with glyphosate. Many growers are using residual herbicides in the burndown application to keep weed growth from coming on before planting. If moisture is conserved from the late March killing of the cover crop, cotton can be planted at almost any time in mid- to late April to early May with good results. 

Starter fertilizer usually helps cotton yields on sandy fields and is more efficient than broadcast applications. This should be considered if high amounts of phosphorus are required. Take care with nitrogen to keep it 1 inch away from the row for each 10 lbs./acre of N applied as a starter. Phosphorus has been shown to be more effective when applied as a starter in a band near the row, or 2” X 2” as compared to broadcast applications. Therefore, consider starter applications if high amounts of P are required for the cotton crop. Test this on your own farm by splitting fields with broadcast applications vs. banded starter applications. We do not recommend “pop-up” fertilizer in row. It will reduce stands in many cases. wright@ufl.edu

ALABAMA | Steve M. Brown

STEVE BROWN, alabama
Steve M. Brown,
Alabama

Planting season always brings a RUSH — both the excitement of starting a new crop and the compelling urgency to get seed in the ground. Delays caused by a wet, cool spring further heighten the need to hurry.

The busyness of planting should not distract us from watching and managing emerging cotton. Thrips continue to be a key pest, one that threatens seedling cotton typically up through the fifth leaf stage and, infrequently, slightly beyond.

At-plant options for thrip control include premium seed treatments, in-furrow sprays and in-furrow granular treatments. The former two usually involve imidacloprid, and the best of the best in-furrow granular product is aldicarb (AgLogic). Under moderate thrip pressure, seed treatments are often insufficient, and sometimes even the “Cadillac” treatment of aldicarb needs a follow-up foliar spray. 

Damage from thrips in a young terminal.

As cotyledons unfold, the tiny, new terminal is vulnerable to the rasping effects of thrips, especially if significant numbers are present or if crop growth is inhibited by cool weather, herbicide injury or other stresses. It’s easy to scout from the truck or tractor and simply look at the overall growth of the seedlings and the health of the new leaves, but the important place — where the action occurs — is the tender terminal. The terminal is next week’s new leaves. If thrips are active in the terminal, the developing leaves will looked ragged in a few days. That ragged appearance may trigger a spray, but it’s one that would have accomplished far more had it been made several days earlier.

Properly timed, needed foliar sprays for thrips affect the bottom line. They make cotton.

There is no substitute for walking, looking and careful examination. The Thrips Infestation Predictor for Cotton from NC State (https://products.climate.ncsu.edu/ag/cottontip/) is an additional tool that can alert you to the likelihood of significant thrip pressure.

Effective early season thrip control is among the keys to a good start. cottonbrown@auburn.edu

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