NEW PRODUCTION SYSTEM FOR COTTON YIELDS BIG RESULTS
During the past 15 years, cotton yields in Mississippi and throughout the
Cotton Belt have stagnated. The yield plateau is generally believed to
result from lack of genetic progress in improving varieties, stress during
the growing season or other unknown factors.
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 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 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 application.
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