Specialists Speaking
Midseason Crop Management ALABAMA Steve M. Brown
Conditions have improved markedly since early May. Maybe I’m alone in wondering, “Will it ever rain again?” O, me, of little faith. I’ve had that mindset before, but it has always rained… eventually. How easy to think “this time” is different; indeed, it is not. Our every-year pests that are predictably troublesome include 1) thrips, 2) palmer amaranth and 3) stink bugs. Unique challenges. Pest problem No. 1 is obviously in the rearview mirror, but it’s helpful to acknowledge that we had heavy thrips pressure in many places this season and that countless fields would have benefited from better, upfront control measures and/or timely foliar sprays. Good thrips control can boost yields by 100 lbs./acre or more — a strong return with cotton prices exceeding $1. We’re still trying to gain the upper hand on pest problem No. 2: glyphosate-resistant pigweed. Product shortages and expanding herbicide resistance increase the difficulty of dealing with Palmer amaranth. Farmers have spent hundreds of millions in dollars fighting pigweed, yet we still lack an easy, sure solution. No doubt some fields will warrant hand pulling. July brings us to pest No. 3: stink bugs — a complex of multiple species that feed on seed in bolls and significantly reduce yield and fiber quality. Three stories about stink bugs. Late in the season of the first year for Bt cotton, I walked fields on back-to-back days with my entomologist colleague and saw good worm control but devastating stink bug damage. I stood still in mature cotton and observed stink bug movement that looked like airplanes over Atlanta. The “light bulb” went off: stink bugs are now a key pest. I recall walking a research trial with the same entomologist. A failure to communicate on a worm control experiment led to a neglect of stink bug control, resulting in yields of 100 lbs./acre rather than 1300 lbs./acre. An area farm tour took our group into a field to examine fertilizer treatments. As we walked into the cotton, the stink bug numbers and damage were shocking — even to an agronomist’s eyes. Upon our departure, it didn’t take long to get a sprayer in the field. Scout for stink bugs! cottonbrown@auburn.edu
ARKANSAS Bill Robertson
The Prospective Plantings report released in March by USDA-NASS estimated cotton plantings in Arkansas at 520,000 acres, up 8% from the 480,000 acres planted last year. The Arkansas Boll Weevil Eradication Foundation had mapped more than 530,000 acres one week into June. We are seeing a lot of new growers this year, and that is reflected in our acre expansion. As the 2022 cotton crop began to square in early June, plant progress was ahead of last year but still slightly behind our five-year average. Cooler temperatures and cloudy conditions slowed the pace of our crop. Our biggest concern in the field to this point has been weed control. This shifts to irrigation late June and early July. We expect to see flowers by July 4 on May 1 planted cotton. Most of our crop was planted the second week of May. At first flower, we like to find nine to 10 first-position fruit above the first white flower. This helps ensure the foundation exists to achieve high yield and fiber quality potentials with our growing conditions. Our goal is to maintain no less than 80% retention going into first flower. To optimize efficiency, we must concentrate on the basics. This includes avoiding excessive nitrogen
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COTTON FARMING | JULY 2022
rates and striving for well-timed irrigation. Maintaining a balance between vegetative and reproductive growth will help to optimize earliness and preserve yield and fiber potential. After cutout, we begin the process of our heat-unit based crop termination strategy. brobertson@uada.edu
ARIZONA Randy Norton
The majority of the state is well into bloom, with some of the state, particularly the western part, approaching or just past peak bloom. For most of the crop around the state, the next four to six weeks are critical for making cotton. Everything we can do to protect the fruit is critical for developing the yield potential that is there. And as of this writing, the early season fruit set looks very promising. So, what are the factors that can affect the crop going into the next several weeks? There are a whole host of things, including proper fertility management, plant-water relations management and pest control, among others. Actively managing these factors that can affect crop development is important. We have control over many of these factors. There are some things, however, that are out of our control — such as days of elevated heat stress. Depending on a variety‘s susceptibility to this heat stress, these events can have a significant impact on fruit load. Monitoring fruit retention and height-to-node ratios will help you manage the crop more effectively. A sudden drop in fruit load will often result in a plant that tends to go into a more vegetative growth phase. Controlling this with plant growth regulators is important to maintain a balance for late-season crop management efficiency and defoliation. For more information on these topics, go to our University of Arizona Cooperative Extension website at extension.arizona.edu/crops-soils. rnorton@cals.arizona.edu
FLORIDA David Wright
Cotton is planted on 110,000 acres in Florida in 2022. Growers have gotten off to a good start this year with stands, although some midseason drought is affecting the crop. Commodity prices are high, and growers using good rotations and management practices can especially make good on yield, pest control and profits. With production prices going higher each year and almost doubling in 2022, it is necessary to do everything possible to make a good crop. Only 25 % to 30% of cotton in Florida is irrigated, so rainfall is critical in crop production in most years. In the several years of below-average rainfall we’ve had, our research with rotations and winter grazing before cotton shows that yields of non-irrigated cotton can often be as high or higher than irrigated cotton in rotations without grazing. Winter grazing prior to cotton results in greater cotton root mass, making the crop more drought tolerant. The additional root biomass can add an average of 150-250 lbs./acre of lint to the cotton. We've also seen high yields at relatively low nitrogen rates if these practices (rotation, winter grazing, etc.) are adopted. As we get more regulations on N use to limit nitrates in wells and springs, low water and N use will help us maintain, and even increase, cotton yields while pumping less water. Cotton being a southern crop can withstand high levels of stress and still produce good yields if we have good weather conditions in July. We are just getting into the rainfall periods for cotton and hope that we see record yields this year with the newer varieties we saw in 2021. wright@ufl.edu COTTONFARMING.COM
