Cotton seed breeding must improve It will take an immediate renewed public breeding effort to attack the problem of stagnant cotton yields and decreasing fiber quality, cotton producer Jack Hamilton of Lake Providence, La., told growers attending the 2001 Beltwide Cotton Production Conference.
According to Hamilton, the U.S. upland cotton yield average has varied between about 500 and 700 pounds per harvested acre over the last 20 years. The low during this period was 580 pounds per acre in 1983 and the high was 780 pounds in 1994.
"Clearly a significant problem exists with current cotton yields," he says. "In recent years, yields have become increasingly variable and highly unstable. In addition to stagnant and volatile yields, the quality has deteriorated as well. This is a double whammy for producers who are struggling to stay afloat financially before they receive the discounted prices, without realizing any offsetting yield increases."
The two qualities of cotton that have shown the most decline and are causing the most problems for producers and textile mills, Hamilton says, are micronaire and staple length.
Over the last 10 years, the average micronaire of U.S. cotton has both fluctuated from year to year, and continued to steadily increase. "The implication for producers is that a larger portion of production is now falling in the higher micronaire range and is either receiving no premium or is being discounted for being too high," Hamilton says.
A similar but opposite trend is occurring for staple length, which has been stagnant to lower over a 10-year period. The last three years are of the most concern, Hamilton says, because the trend has been sharply lower. "This has really impacted producers and is hitting our pocketbooks because there is a significant price discount for short staple cotton."
"The area I am from in northeast Louisiana has also seen short staple lengths over the last few years. In the 22 crop years since 1979, there have been only five years in Louisiana where the percentage of our crop with a staple length below 1-1/16 inches has exceeded the double digits," he says. "These years were 1980, 1991, and the last three years - 1998, 1999 and 2000. In fact, in the last two years over 36 percent of our crop have had a staple length below 1-1/16 inches. The average for the other 17 years was 2.2 percent of the crop with a staple length below 1-1/16 inches."
Although weather information for these years tends to indicate rainfall and temperature had a great effect on staple length, it's obvious varieties also played a big part, Hamilton says. "The first and foremost reason for cotton yield and quality problems is a definite lapse in cotton breeding efforts. Where, in the past, cotton variety work was often done by private companies in the public interest, it is now primarily in the hands of major chemical companies. Their main interest of course is to sell chemicals, not to develop outstanding cotton varieties."
Another reason for the downtrend in quality and yield, according to Hamilton, is producers' request for shorter-season cotton varieties. Producers have asked breeders to develop shorter-season cotton in order to decrease both input costs and the chance of detrimental weather. However, he says, today's cotton varieties tend to be more determinant and less able to overcome weather extremes during a compressed growing season.
The third factor, Hamilton says, is the inability of genetic engineers to translocate genes into the popular varieties. "These engineers translocate the genes into Coker varieties and then backcross into the more popular varieties, but some of the plant material may remain and this could be causing part of our problem."
The answer to the double-edged problem of yield and quality, he says, is to immediately regenerate the public breeding program. "Many of our land grant colleges and universities have cotton breeders in their research and Extension departments. Additionally, the Agricultural Research Service with USDA has always had cotton breeders on staff. We feel that this breeding work is not being coordinated among the different researchers and the results are not reaching the commercial cotton farms in this country.