I usually release variety trial results with little to no narrative, just a few sentences indicating results are now available. But this year, there are several points of emphasis that warrant more. In this post, I try to explain what happened in 2024 as a way to guide interpretation of the variety trial results. It is a long post, but I believe this is a must read for those who intend to use the 2024 TN Variety Trial Results in their variety selection decisions for 2025.
No one within Tennessee who claims to know anything about agriculture would suggest 2024 was a ‘typical’ year. Sure, I’ll concede that abnormal is normal, and there is never a ‘typical’ year. But what we experienced through May really was abnormal. This was the first year in recent memory where we were unable to plant almost a third of our intended cotton acres. The rainfall amounts and pattern through May and June crippled if not eliminated taproot development and severely damaged the crop’s ability to endure the drought stress which we experienced through August. And while God gave a few counties a ‘million-dollar’ mud-rain in late July, many of us watched that rain pass by just beyond our fence row.
Then came the hurricanes. I’ve heard people repeatedly say hurricanes wrecked our early crop, and while I’ll again concede that the hurricanes didn’t help, I’ll argue both hurricanes mainly masked the crop’s response to our drought. Our earliest planted acres, which were far too wet for their first 50 days then far too dry for their next 50, generated some of the smallest bolls I’ve observed in the Midsouth- many with as few as 3-5 seed per lock. In my opinion, with or without rainfall in a cracked boll, locks with so-few seed rarely fluff well enough to allow the picker to harvest them- hardlock was coming with or without Helene and Francine.
Understanding the environmental conditions which drove the crop response is critical in properly interpreting the 2024 Tennessee Cotton Variety Trial Results. As you begin flipping through this document, you will observe abnormally low yields from some locations. You will also note higher coefficients of variance- that is a measure of how much unexplained variability was present within the trial results. The low yields and higher variability, particularly in the Jackson locations, were both driven by drought response. Unfortunately, when yields are low, CVs are naturally higher. While we attempt to ‘rep-out’ or avoid inconsistent areas of a field, a drought as severe as the one we experienced in parts of West and Middle TN allows soil properties- mainly plant available water as limited by sand content- to become the dominant factor in small plot yield response and dwarf variety response. Small plot research can be extremely challenging in drought environments at locations where soil properties vary even in the slightest bit. The noise present in these locations does limit variety separations, but when pooled in the overall average table, separations do become stronger. When reviewing the overall averages table, keep in mind that the responses reported represent variety response in all six OVT locations- this includes the1,400+ lb per acre Grand Junction and Ridgely locations and the 800lb and 600 lb per acre early and late planted Jackson locations. Subsequently, an A group variety on the overall list is a variety that proved to have both a backbone and top-end yield potential.
Our large plot testing program, as you might expect, followed our Tennessee cotton acreage number and was also off by almost 30 percent on number of trials established. Even so, the variety separations generated by the CST program were some of the strongest that we’ve been able to generate, with very low CVs. Fortunately, large plot data is generally less sensitive to small spatial variations in soil properties. Although we only have just shy of a dozen varieties included in the overall average table, I believe most will find substantial value in these responses. We have also struggled in the past several years to find cooperators who will plant trials that are not XF. While we did report two locations including mixed technologies in 2024, I do not think we have a large enough dataset to generate a table reporting variety performance across the technologies with the CST data. For head-to-head performance across tech platforms, you will need to look at the OVT data.
Two final thoughts. First, I would like to thank the cooperators from the 2024 season and put in a plug for participation in the 2025 testing program. I know many who read this or pick up our trial results have participated in the program in the past or may currently be participating in the program. Thank you! To those who have not participated, please consider reaching out to your county agent to let them know you would be willing to participate. This is an agent-led, grower focused program. Our ability to generate quality variety responses and ultimately separations is linked to the number of growers committed to generating the data. Without your participation, the value of this data will be extremely limited.
Finally, despite the challenges associated with cotton production during 2024, the state average cotton yield is still going to fall very close to 1,000 lb per acre. I watched the mud rain miss Jackson and spent days walking cotton that fell short of 800 lb per acre. Those who asked heard me estimate state cotton yields through the end of Sept and even into Oct to be near 900 lb. I underestimated the scale and impact of that single rain event in July and I will happily stand corrected. As we look towards what appears to be thin margins in 2025, keep in mind that even in a really tough year, for most of us, cotton produced. Within the next few months, I’ll be sharing some thoughts on how we might agronomically navigate these tight times. This will be the central theme for Cotton Focus, which is quickly approaching on Feb. 11th at WTREC. As always, please reach out to your county agent if you have any questions on this or anything else pertaining to cotton production. I hope you have a successful 2025 and look forward to seeing you during this meeting season.
