USDA cotton geneticist Todd Campbell is testing cotton breeding lines that incorporate the best qualities of several different cotton species native to locations as far away as Africa and South America.

Giving cotton a global look, Campbell says, is all part of trying to provide cotton breeders and ultimately cotton growers with the best possible varieties for growing upland cotton in the Southeast.

Speaking at a recent field day at the Florence, S.C. facility, Campbell said future cotton varieties will need to go global to meet the demands of foreign cotton buyers.

Campbell conducts most of his field research at Clemson University’s PeeDee Agricultural Research and Education Center in Florence, S.C. Additional field work is conducted at the Clemson Edisto Agricultural Research and Education Center in Blackville, S.C.

He has a conventional cotton breeding program, a second program to look at genetic variability, and a third program to look at specific genetic qualities desired in cotton varieties in the Southeast.

The goal of the research program is to increase cotton genetic diversity and develop high yielding and high quality germplasm lines that can be used to develop commercial varieties.

The breeding program has already produced five breeding lines that have produced yields comparable to the gold standard for cotton varieties — DPL 555.

In tests at both Florence and Blackville in 2009, four of these varieties, all numbered breeding lines, averaged between 1,365 and 1,397 pounds of lint per acre. All four varieties had a fiber length of 1.15 inches, all had between 32 and 34 grams fiber strength and had gin-outs of 41 to over 43 percent.

Good quality, big yield
Campbell says all five of the varieties he is testing in South Carolina have fiber length, strength and micronaire desired by foreign mills. Plus, these varieties have high yield potential in the Southeast.

“We’ll know later this year whether we will try to release one or more of these breeding lines as a new variety. Or, we’ll decide whether to continue testing these varieties another year,” Campbell says.

Yield is always important, but in today’s global market quality can be an over-riding factor. Foreign buyers are looking for fiber length, strength and other quality factors different than domestic textile mills. Unfortunately, less than 10 percent of the cotton grown in the U.S. goes to the declining domestic market.

In another part of his program, Campbell is adding some genetic twists to commonly used upland cotton varieties. He explains that virtually all cotton grown in the Southeast is upland varieties. The scientific name for upland cotton varieties is Gossypium hirsutum.

Sea Island or Pima cotton, grown primarily in the southwestern U.S., has some excellent fiber qualities that could benefit Southeastern growers. The USDA researcher is transferring genetic material form Pima cotton to upland varieties and testing breeding lines at the two South Carolina research sites

It’s a major scientific challenge to make sure these Pima traits show up in upland cotton varieties. Then it’s even more challenging to determine whether these traits are beneficial to Southeastern growers.

Campbell also is looking at a cotton species native to Hawaii called Gossypium tomentosum and at several upland cottons native to South America and Africa. The hope, he says, is to find some genetic qualities for heat and drought tolerance that will be helpful if incorporated into upland varieties.

Corn breeders have had success in recent years in taking advantage of hybrid vigor and Campbell is trying to find some of the same advantages by making hybrids from popular upland cotton varieties.

In his South Carolina tests, he has evaluated a number of upland cotton hybrids. The results, he says, have been good so far. In each test, several of the hybrid cottons out-yielded the average of either of their two parent lines.

Campbell is part of a multi-state team seeking to improve mapping of the cotton plant genome. Once this is more complete, it will make development of hybrid varieties much more common.

The demand for different cotton fiber qualities is there and the scientific tools are available to give cotton varieties a more global look in the future. Putting all the pieces of the puzzle together will take time, Campbell says.