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Alabama Cotton Shorts

December 15, 2020

December 15, 2020

Situation. Average yield and total production for the 2020 Alabama crop were estimated to be 852 lb/A from 445,000 acres for a total production of 790,000 bales according to the December USDA report. We’ve seen significant, weather-related declines since August. The initial USDA estimates were 981 lb/A and 950,000 total bales. In late summer, we were convinced that we had a good, if not very good crop. Hurricanes, tropical systems, and prevailing rainy, cloudy conditions have hurt both yield and quality.
 
Bales ginned and fiber quality data are tabulated below for the week ending December 11 and for the overall seasonal average.
The number of Extraneous Matter (EM) calls of seed coat fragments (SCF) is unprecedented. There’s never been a crop with this much SCF. Extraneous Matter calls are made by the human eye and touch, not HVI equipment. Extraneous Matter categories and codes are listed in the table below. Deduction in cotton loan value for Level 1 EM is 4.45 cents per pound; a Level 2 call, which indicates a greater amount of unwanted material or worse overall condition, is a 7.05 cents per pound penalty.
 
 Extraneous Matter Code  Comment
  Bark 11   Shredded stalk, stem material
  Grass 21   Grass, nutsedge vegetative material
  Seed Coat Fragment 31   Seed ground into lint
  Prep 01   Rough appearance
  Other 61   Oil, etc.
  Plastic 71   Shopping bags, bale wrap, plastic twine
 
We’ve shared information and thoughts about SCF with Dusty Findley of the Southeastern Ginners Association and engineers at the USDA Cotton Ginning Research in Stoneville, MS. Our consensus is weather is the obvious, primary factor driving the issue. We don’t believe it is variety related, and we doubt there are significant differences among gins except by geography. About two thirds of the cotton ginned in Alabama go to the USDA Classing Office in Macon, GA. The remainder goes to Memphis. Birmingham is the general (but not absolute) dividing line between what goes east to Macon and what goes northwest to Memphis.
 
Note the DRAMATIC differences in EM / SCF in Macon versus Memphis. Much of the crop in the southern half of Alabama had 20 inches of rain or more on open cotton, with relatively warm temperatures. Seed sprouted and generally degraded. There’s also evidence of immature seed passing through to the lint fraction. Rainfall, warm temperatures, and weathering are the probable causes. Late season regrowth and the thrashing action of Hurricane Sally may also have adversely affected seed development and boll fill. (Brown)
2020 Alabama Row Crops Short Course Video Series
2020 Alabama Row Crops Short Course Video Series. Although we are unable to host the Alabama Row Crops Short Course in person this year, the ACES Crops Team has worked to create a Short Course Video Series to prepare producers for the upcoming growing season. Videos focus on timely topics for improving profitability and feature expert speakers from Auburn and other land-grant universities. Videos are now available at https://cses.auburn.edu/2020-alabama-row-crops-short-course/
 
Topics for the 2020 Alabama Row Crops Short Course Video Series include:
 
• Farmer Panel on Cover Crop ManagementAnnie Dee, Matt Haney, and Myron Johnson
• Crop Market OutlookDr. Adam Rabinowitz and Dr. Wendiam Sawadgo, Auburn University
• Herbicide Applications in a World with DicambaDr. Greg Kruger, University of Nebraska
• Nematode Resistant Cotton VarietiesDr. Kathy Lawrence, Auburn University
• Cotton Leaf Roll Dwarf Virus UpdateDr. Amanda Scherer, Auburn University
• Potassium Management for High-Yielding CottonDr. Glen Harris, University of Georgia
• Wild Hog ManagementDr. Mark Smith, Auburn University
• Weed Control in Xtendflex SoybeanDr. Connor Ferguson, Mississippi State University
• Redbanded Stink Bug Management in SoybeanDr. Tyler Towles, Louisiana State University
• Seed Quality Issues in PeanutDr. Scott Monfort, University of Georgia  (Gamble)
AU OVTs Data Available On-line. Results from the small-plot official variety trials (OVTs) conducted on the Auburn University Research and Extension Centers can be accessed at the Auburn University Variety Testing Website. Henry Jordan, Variety Testing Manager, indicates lint yields for all trials are posted and quality data are almost complete as well. Fiber quality comes from analysis at the USDA Classing Office in Memphis.  (Brown)
Bt Cotton Update. The Auburn Cotton Entomology team conducted several research trials in 2020 to help us continue to refine the “Cotton IPM System.” Below are short summaries of some of the work we did to monitor bollworm resistance to the Bt cotton technologies planted in the state. Although 2017 taught us that the threat of escaped bollworms is real, we have not had a significant outbreak since then. Overall, our recommended Bt technologies (Bollgard 2, BG3, WideStrike3, TwinLink Plus) provided excellent control of bollworms. Our current recommendation is to plant the varieties that have the highest yield potential on your farm, regardless of Bt technology. We still need to scout for bollworms and be prepared to treat, but so far that has not been the case very often since 2017.

Establishment of Bollworm Sentinel Plots on Research Farms Throughout Alabama. Bt sentinel plots were established on research stations across Alabama to monitor the in-season efficacy of 2- and 3-gene Bt technologies against bollworms. Plots were planted as non-replicated 4-row strips at least 100 feet long and were managed for bug pests (i.e. plant bugs, stink bugs) using insecticides that do not have activity on bollworms. At the end of the season, a damaged boll count was done to determine how well each technology protected cotton from bollworm compared to the non-Bt check. In 2020, WideStrike3, TwinLink Plus, Bollgard 2 and Bollgard 3 Bt technologies provided excellent protection against bollworms in all locations (Table 9). These sentinel plots support the recommendation to plant Bt varieties that have the highest yield potential on a given farm, regardless of the Bt technology, as each currently provide adequate control of bollworms. 
 
Table 1. Number of damaged bolls found prior to harvest in Bt cotton sentinel plots planted at five research stations across Alabama (2020).
    Number of Bollworm Damaged Bolls per 100 row feet
 Technology Prattville Fairhope Brewton Headland Shorter Average  
  Non-Bt 18.9 8.7 100.0 8.5 7.0 28.62
  WideStrike 4.5 1.7 20.3 2.3 2.0 6.16
  WideStrike 3 0 0 0 0 0 0
  TwinLink Plus 0 0 0 0 0 0
  Bollgard 2 0 0 0 0.7 0 0.14
  Bollgard 3 0 0 0 0.2 0 0.04
Figure 1. Damaged bolls collected from Bt sentinel plots in Brewton, AL (2020).
Monitoring Bollworm for Resistance to VIP Bt Technology. A block of non-Bt field corn was planted on research stations across Alabama to collect natural populations of bollworms to be screened for resistance to the VIP technology (e.g. Bollgard 3, WideStrike 3). Populations were collected and shipped to Dr. Dominic Reisig at NCSU to be screened against the VIP3Aa39 protein in the laboratory. The amount of VIP protein needed to kill 50% of the field population was compared to the amount needed to kill 50% of a lab colony that had never been exposed to the protein prior to testing. The tests showed that bollworm populations from Alabama in 2020 were as susceptible to the VIP protein as lab colonies. This confirms that we do not have VIP resistance as of 2020.  (Graham and Smith)
 
Table 2. Resistance ratios of field collected populations of bollworms collected from non-Bt field corn across Alabama (2020).
 Bollworm Population  Source LC50 (ug/cm2) Resistance Ratio*
  Susceptible   Benzon (Lab) 1.22 -
  Susceptible   Lab SS-Tx 0.38 -
  Fairhope, AL   Non-Bt Corn 0.44 -3
  Prattville, AL   Non-Bt Corn 0.34 -4
  Brewton, AL   Non-Bt Corn 0.38 -3
  Belle Mina, AL   Non-Bt Corn 0.22 -6
 *Resistance Ratio= field collected population LC50 / lab population LC50
  Data from D. Reisig, NCSU
Dr. Ron Smith, Extension Entomologist, Professor Emeritus, (right) receiving a token of appreciation from Blount County farmers Jimmy and Lance Miller.
Looking Back as a Career Winds Down. I began my career as an Extension entomologist at Auburn University on April 24, 1972. To put that in perspective -- Richard Nixon was president and the Vietnam War was still ongoing. I have worked under the direction of eight Cooperative Extension Directors and too many Deans of the Ag School/Experiment Station to count.
 
It has been quite a journey to have been a part of the most evolutionary period ever in cotton insects. I began my career when boll weevils were the key and dominant cotton insect in Alabama and as part of the new USDA-Extension cotton IPM educational initiative. Each cotton producing state received new federal funding to add one additional cotton entomologist. Two states, North Carolina and Arizona, added an additional entomologist a year earlier, in 1971. The special funding for this program effort continued for more than 30 years. The goal of this new program was to increase the awareness of a management approach to controlling cotton pests. The Extension cotton scouting program and use of economic thresholds, which forms the basis of a management approach, was initiated by Drs. Walter Grimes and Roy Ledbetter with the aid of Mr. Frank McQueen (survey entomologist) in the late 1950's and early 1960's. During the early to mid-1970's our primary cotton insecticide tool was the organophosphate class of chemistry. The organophosphates such as methyl parathion and Guthion were characterized by fast acting activity but short residual. In addition, most chemicals in this class had acute human and mammalian toxicity. The phosphate chemistry had excellent activity on the boll weevil but brought on resistance in the tobacco budworm and secondary pests such as spider mites and whiteflies. The heavy use of phosphate insecticides also caused major problems with delayed crop maturity. This problem with delayed maturity was so pronounced that a special session was added to the Beltwide Cotton Research and Control Conference in January of 1976.
 
In 1976, the pyrethroid class of chemistry became available, first under an EPA-issued emergency use permit (EUP). In 1978, pyrethroid insecticides received full but conditional registration and became the major player in cotton insect control for the next decade. For a few years, pyrethroids were highly effective on most all cotton insects. Insect losses were very low, yields reached a new higher plateau, and maturity issues disappeared. Due to extended residual from the pyrethroid insecticides (Ambush, Pounce, and Pydrin) application intervals for the boll weevil could be extended from 5 to 7 days. However, during the decade of the 1980's, depending on the area of the Cotton Belt, tobacco budworms became resistant to the pyrethroid class of chemistry.
 
It was during this time period that the final plan to eradicate the boll weevil was being formulated. This program had been in the development for more than a decade. One of the big driving forces to eradicate the weevil was the possibility that boll weevils might develop resistance to the organophosphate class of chemistry. This possibility would have wrecked the cotton industry in the U.S. Pyrethroids had activity on the weevil but were not as effective as the phosphates and were initially significantly more expensive. The boll weevil never developed resistance to the phosphates; in fact, the phosphate insecticide malathion was the primary insecticide used for eradication.
 
In the fall of 1986, the organized boll weevil eradication initiative reached Alabama. This program was first started in northeastern N.C. (Chowan Co.) a few years earlier. Twenty one counties in southern Alabama were included in the first eradication zone. During the following 7 years the program was expanded throughout the remainder of the state (Central AL -1992, NE AL-1993, and TN Valley-1984). By the summer of 1995, no economic losses to the boll weevil could be found anywhere in the state.
 
During the eradication program period (1986-1995), insecticide resistant tobacco budworms and impossible-to-control beet armyworms caused yield losses beyond anything ever observed or previously recorded. During one season, yield losses to beet armyworms alone were estimated to be about $40 million across the state. At the end of the 1995 season the outlook for the future of cotton production in Alabama was bleak.
 
Fortunately, genetically altered Bt (Bollgard) cotton varieties, which had been under development and evaluated in select fields for the previous four seasons, became available to growers. This new technology was readily adopted by Alabama growers and 77 percent of the 1996 acreage was planted to Monsanto Bollgard varieties. This rapid adoption was primarily in self­defense following the heavy losses to worms the previous years. However, planting this new technology brought with it rules and regulations never experienced before by growers. Word was spoken that growers would never have to treat for worms again. This proved to be incorrect when in late July 1996, news of boll worm escapes in the Brazos River area of Central Texas spread across the Cotton Belt. It was only about one week later when this escape bollworm and fall armyworm problem was observed in Baldwin Co., Alabama. Some growers wanted to give up on this new technology immediately. However, over the following years entomologists and growers learned more about what to expect from Bollgard cotton varieties and how to manage escaped bollworms, which could be controlled with a minimum of well-timed pyrethroid sprays. The following 10 years proved to be good for growers with overall improved yields and minimal insect losses and control costs.
 
It was during this low spray environment that the bug complex became more damaging to yields. In north Alabama it was the tarnished plant bug that had to be monitored and managed more closely. In central and south Alabama, as well as the remainder of the Coastal Plain of the Southeastern U.S., it was the stink bug that became the dominant economic insect of cotton. Entomologists in the Carolinas, where the weevil was first eradicated, had reported that stink bug damage increased. However, populations of the southern green stink bug in the southeastern U.S. caused even greater damage than did the green stink bug species in the Carolinas. It took several years for growers and fieldmen to realize how devastating the stink bug could really be.
 
By the time better stink bug management was adopted, the Bollgard technology, with one Bt gene, began to lose its effectiveness and escape bollworms were more widespread . Experts had warned that this phenomenon would happen since the single Bt gene was never 100 percent effective on the bollworm species, as it was on the tobacco budworm. Anticipating this, Monsanto had begun work on stacking a second gene. This second Bt gene entered the market in 2009 and reduced this escape bollworm problem by about 90 percent, followed by Bollgard III in 2018. WideStrike genes from Dow AgroSciences (PhytoGen varieties) first became available in 2005 and were followed by the third gene (WideStrike3) in 2014.
 
Cotton insect control overall from 1996 to 2020 has been good with no boll weevils or tobacco budworms and minimal escape bollworms in the system. However, sucking pests such as thrips, aphids, whiteflies (silverleaf) and spider mites have required monitoring and management. In addition, due to reduced tillage trends, certain sporadic or new pests have had to be contended with. Some of these are grasshoppers, cutworms, snails, slugs, and early season spider mites. However overall, the past two decades have required careful monitoring and selective management and control skills, but insect losses and control costs have been historically low and have served to keep the cotton industry profitable in Alabama.
 
The evolution of cotton insect management is so great that fire ants are now considered as the number one beneficial insect against escape bollworms in our reduced tillage systems. It is felt by several entomologists that fire ants are playing a big role in allowing Alabama growers to continue to plant two-gene varieties, primarily DP 1646, without the need for costly diamide chemistry (Prevathon and Besiege) oversprays. The diamide chemistry, developed by Dupont, is highly effective when applied timely on most worm species. What would have been a significant development, had it not been for the introduction of genetically modified genes back in 1996, was the introduction (1996-98) of spinosad (Tracer) chemistry by Dow AgroSciences. For the first time since the development of synthetic pesticides in the 1940's, caterpillar pests could be controlled with this selective chemistry while lady beetles and other beneficial insects were not affected and remained in fields.
 
More recent years of cotton insect control have been dominated or characterized by the emergence of sucking pests, such as aphids, spider mites, thrips, and whiteflies (silverleaf), and the bug complex (plant bugs, stink bugs, and leaf-footed bugs). As we moved into this reduced foliar spray era following the elimination of the boll weevil and tobacco budworm, our chemical tools became more selective. Our new caterpillar insecticides do not control sucking pests or the bug complex and the sucking pest insecticides do not control the bug complex or escape bollworms. Insecticides targeted for the bug complex give limited control of sucking pests or escape caterpillars. Tank mixes of two or more insecticides are again often necessary. In the 1950's and 60's, most insecticides were formulated as mixtures at the distribution level. Now, these mixtures are prepared on the farm as the sprayer is being loaded.
 
The future will likely continue to be dominated by our current conditions. New advances may be limited. Few new chemistries will be developed. Development cost of chemistry cannot be recouped from cotton usage alone, as was done in the earlier years. New chemistry developed today must find market share with all row crops along with vegetables, fruits, nuts, and other grain and food crops. New advances will likely come in the form of genetics. These advances take years of research and development and as many or more regulations as chemicals. A thrips-lygus gene is nearing the marketplace in 2021. Based on research, this gene may prove most effective on thrips with moderate activity on plant bugs. It will not help on stink bugs, which are likely to continue to be the dominant economic insect in Alabama and the Coastal Plain of the Southeastern U.S. Rather than advancing the discipline of row crop and cotton entomology, our future may be described as a "keep up with resistance" in the decades ahead. Resistance issues are present today in the following species: thrips, plant bugs, bollworms, spider mites, aphids, and possibly other species. The greatest challenge in entomology today is staying ahead of resistance and managing sporadic pests such as slugs, snails, cutworms, grasshoppers, three-cornered alfalfa hoppers, leaf-footed bugs, and others. Reduced tillage has been a great advancement; however, this practice has created numerous cracks that are being filled by sporadic pests that require the attention of entomologist and fieldmen advisors.

In summary, the past 48 years of cotton production and insect management have evolved in many -- and in some instances -- unexpected ways. Examples include:
  • The change from intense cultivation to reduced tillage and heavy dependence on herbicides.
  • The development of major resistance issues with weeds and numerous insect species.
  • The development of Increased problems with nematodes and, potentially in the future, plant viruses.
  • A shift from boll weevils to the stink bug complex as the most economic insect.
  • A switch from phosphate chemistry to the pyrethroids and now the diamide chemistry.
  • The change from 5-day insecticide application schedules for boll weevils to 2 to 4 seasonal foliar sprays.
  • The escalation from nominal seed cost to very expensive seed and trait costs.
  • The change from moderate expenses per acre spread across the season to high, front-end budget inputs.
  • A shift from a few secondary pests to numerous new sporadic pests.
  • The change from Extension ag agents in every county to a regional agent with responsibilities spread over as many as 15 counties.
  • The shift from primary information sources of Extension agents/specialists and insecticide distributor salesmen to private consultants and well-trained commercial agrifieldmen.
  • The change from print media to electronic tools.
What an evolution and what a ride for an Extension entomologist! Always a challenge, always an additional idea on how to educate or have a more positive impact on cotton pest management. Job never complete nor finished, but most rewarding job in the world. Spent a career trying to help my friends manage their insects. Knees are worn out but the mind is still going. Desire to be involved for a few more years in some capacity.

I will end with a thought and a quote from one of my all-time favorite books, Red Hills and Cotton-An Upcountry Memory by Ben Robertson, 1940. 

"Cotton is the greatest crop heaven ever gave to a country,"

(Dr. Ron Smith, Extension Entomologist, Professor Emeritus, All-Around Great Cotton Man)

This issue contributors:
Dr. Audrey Gamble, Extension Soil Scientist
Dr. Scott Graham, Extension Entomologist
Dr. Ron Smith, Professor Emeritus, Extension Entomologist
Dr. Steve M. Brown, Extension Agronomist  (Editor) typos and other mistakes are mine 

About the Alabama Cotton Shorts Newsletter
Alabama Cotton Shorts is a newsletter designed to keep cotton producers in the know. From planting dates to crop inputs—there are many factors to consider. The Alabama Cooperative Extension System is dedicated to providing science- and research-based information, derived from field experience and observations. A team of Extension specialists are working to provide Alabama farmers with timely information throughout the growing and harvest seasons.

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