To overcome this problem, Bill Pettigrew, a plant physiologist with the Agricultural Research Service's Crop Genetics and Production Research Unit in Stoneville, Miss., developed a production system that could allow cotton yields in the Mid-South, and perhaps other areas, to resume their historic upward trend. The key is an earlier planting schedule that boosts yields because the plants receive more sunlight at the right time.
Normally, peak cotton blooming occurs about the second week of July. By planting earlier, growers can shift this peak blooming closer to June 21, the longest day of the year, when potentially more sunlight is available.
Also, cotton bolls should benefit from more rainfall in June and early July than is available later in the summer.
To test his system, Pettigrew planted different upland cotton varieties during the first week of April and the first week of May from 1996 to 2000. He compared crop growth, development, lint yield and fiber quality in early and normal plantings. Pettigrew found plants bloomed sooner four out of five years when planted earlier. Yield also increased 10 percent, on average, those four years. And though an early-season cold period stunted the early-planted crop in 1997, yields from both crops were equal.
His system, called the Early Planting Cotton Production System, provides greater lint yield and avoids many late-season stresses — such as insects, high temperatures and low moisture — while reducing the need for late-season irrigation and insecticide applications.
Drawbacks could include increased risk of seedling exposure to cold stress and increased seedling infections by soil-borne pathogens in cool and damp conditions. However, several fungicides now available help control seedling diseases. Pettigrew is exploring other techniques to minimize cold weather hazards.
ARS is the U.S. Department of Agriculture's chief scientific research agency.