In February, you might be feeling the pressure as growers ask for cotton varieties that not only deliver better yields and fiber quality but also withstand rising temperatures. Heat tolerance matters, of course, but it’s not the only trait your growers should consider when choosing varieties this winter.
While it’s a misconception that cotton plants are heat-proof, some varieties tolerate heat better than others. Here’s how to guide your growers through seed selection with heat stress in mind.
How heat stress impacts cotton yield and fiber quality
Heat stress can have several physiological effects on cotton, particularly on fruit retention, boll development and fiber quality. Here’s the low-down to pass along to your growers:
When cotton plant varieties are marketed as heat tolerant, these traits don’t eliminate the impacts of heat stress, but they can help reduce losses when high temperatures become problematic.
More heat-tolerant cotton varieties may maintain better fruit retention under stressful conditions. Research shows boll retention can decline sharply when temperatures exceed 95 F. At 104 F, boll retention dropped to nearly zero in the conditions studied as plants aborted squares and young bolls.¹
This fruit loss can delay maturity and reduce overall yield. Heat stress can also trigger a shift back toward vegetative growth, known as regrowth, as plants redirect resources away from reproductive development.²
High temperatures can also interfere with fiber development, potentially reducing fiber length, strength and overall quality. Heat tolerance can help reduce these effects, but it doesn’t guarantee that a variety will maintain yield and fiber quality under extreme conditions.
How to help growers evaluate heat-resistant cotton varieties
Finding the best cotton varieties for each grower starts with evaluating their soil types, growing conditions and herbicide programs. While yield potential is a major consideration, several other factors influence overall profitability. Here are a few starting points to review with growers before they choose a variety.
Start with local cotton variety trial data
Local variety trials, often conducted by local extensions through on-farm variety trials, can help you determine whether a variety’s heat tolerance translates into reliable yields. Look for replicated trials conducted under growing conditions similar to those your customers experience, particularly during hot, dry seasons.³
Rather than focusing on the highest yield from a single trial, compare results across multiple locations and years. Consistent performance can be a better indicator of how a variety will perform when growing conditions become challenging.
Match cotton varieties to irrigation capacity
Heat tolerance doesn’t eliminate the need for adequate moisture. Even early-season water stress can reduce yield potential long before the crop reaches peak water demand.
North Carolina State University researchers reported yield losses of 400 to 600 pounds per acre when irrigation was withheld during a critical week of squaring, despite proper irrigation during bloom.⁴
Help growers consider their irrigation capacity, soil moisture-holding characteristics and expected rainfall when evaluating heat-tolerant varieties.
Consider maturity windows and fiber premiums
When discussing variety options with growers, consider how maturity windows may influence profitability. Varieties that mature within the available growing season may have a better chance of completing boll development before late-season stress or harvest termination.
Remind growers that fiber quality deserves equal consideration. Characteristics such as micronaire, fiber length and strength can drive premiums and discounts, so evaluate a variety’s overall economic performance rather than yield potential alone.⁵
Heat tolerance is valuable, but no single trait guarantees a successful cotton crop. Help growers evaluate local performance, irrigation availability, maturity and fiber quality alongside heat tolerance to select varieties suited to their fields and profitability goals.
Experts are available to help you make the best cotton variety recommendations. Reach out to a nearby extension office agent or a seed company professional like your regional BASF representative.
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Endnotes
- Naveed, Salman, et al. “Insights into Cotton Regrowth and Management.” Land-Grant Press, Clemson Cooperative Extension, 19 Aug. 2024,https://lgpress.clemson.edu/publication/insights-into-cotton-regrowth-and-management/.
- Naveed et al. “Insights into Cotton Regrowth and Management.”
- Barrow, Billy. “2025 Cotton Variety Trial Results.” N.C. Cooperative Extension, Bertie County Center, North Carolina State University, 26 Nov. 2025,https://bertie.ces.ncsu.edu/news/2025-cotton-variety-trial-results/.
- Collins, Guy, and Keith Edmisten. “Cotton Is Still Small.....Do We Even Need to Think About Irrigation?” NC State Extension, North Carolina State University, 14 June 2024,https://cotton.ces.ncsu.edu/news/cotton-is-still-small-do-we-even-need-to-think-about-irrigation-collins-edmisten/.
- Sidhu, Sudeep S., Gabrielle A. Comitre, and Hardeep Singh. “Understanding Cotton (Gossypium hirsutum L.) Fiber Quality for American Upland Cotton: From Field Factors to Market Consequences.” UF/IFAS Extension, University of Florida,https://ask.ifas.ufl.edu/publication/AG503.
