Specialists Speaking
Randy Norton / ARIZONA
Cotton Planting Considerations for Today’s Conditions
Recent warm weather across Arizona has led many to begin thinking about the planting season. While early-season warmth can create opportunities for timely planting, increased weather variability in recent years has made planting decisions more risk-driven than calendar-based.
Soil temperature remains one of the most critical factors influencing successful cotton establishment. Optimum soil temperature at seeding depth is 60°F. This condition is typically achieved when overnight low air temperatures remain above approximately 48°F and daytime high temperatures consistently exceed 80°F. Rather than relying on planting date alone, growers are encouraged to track actual soil temperature trends and evaluate short-term weather forecasts when making planting decisions.
Soil temperature should be measured at planting depth in the early morning, around 8 a.m., when temperatures are at their daily minimum. An inexpensive soil thermometer can provide valuable field-level information, and many growers now rely on digital soil probes or on-farm weather stations. When soil temperatures reach 60°F and a favorable three- to five-day forecast is ahead, planting conditions are generally suitable.
Planting into cooler soils can significantly reduce seedling vigor, leading to delayed emergence and increased susceptibility to seedling diseases. While modern seed treatments provide improved early-season protection, they do not replace the benefits of planting into warm soils that promote rapid, uniform emergence.
Determining appropriate seeding rates and final plant populations is another key consideration. Cotton has a strong ability to compensate for variable plant spacing, and research in Arizona has shown optimal final populations generally range from 30,000 to 50,000 plants per acre. With higher seed costs, achieving an optimal — not excessive — plant population is increasingly important.
Seed size varies among varieties, so planters should be calibrated based on seeds planted per acre rather than pounds of seed per acre. Precision planting equipment is now widely used and allows for improved seed placement, better stand uniformity, and more efficient seed use.
Successful cotton planting ultimately depends on matching planting decisions to field conditions rather than the calendar. Monitoring soil temperature, preparing a uniform seedbed, and using appropriate seeding rates and planting technology can help reduce risk and improve early-season establishment. ∆
Randy Norton / ARIZONA