Shedding More Light on Cotton Increases Yields

Planting Midsouth cotton a month earlier to shift the peak flowering period yields more cotton bolls and fiber, a recent Agricultural Research Service study suggests.

ARS scientists at the Cotton Physiology and Genetics Research Unit in Stoneville, Miss., investigated earlier planting times because cotton in the Midsouth region in particular suffers from insufficient sunlight or light deficiency. The region includes Mississippi, Arkansas, Louisiana and western Tennessee.

In the first year of a multi-year field study, the ARS scientists planted cotton during the first week of April, a month earlier than usual. This “ultra early planting” shifts the peak flowering period closer to the summer solstice--the longest daylight period--when plants can soak up more light.

Ultra-early-planted cotton produced 11 percent more fiber, known as lint, than cotton planted at the normal time.

Cotton planted in April also flowered approximately 2 weeks earlier than the other crop. This would let growers harvest and get the crop to market earlier. Prices are higher then because available supplies are lower. Another advantage of early maturity: Growers can avoid the greater insect pressures that occur later in the season.

One disadvantage to ultra-early planting is that some plants may suffer early-season cold stress. But studies so far show that, even if the plants are cold-stressed, yields can be about the same as for normal planting. The scientists are trying to identify more cold- tolerant varieties.

Scientific contact:William T. Pettigrew, Cotton Physiology and Genetics Research Unit, Stoneville, Miss., phone (601) 686-5234, fax 686-5218, bpettigr@ag.gov.