Cotton seed companies in the Southeast are pursuing similar goals when it comes to delivering varieties with low micronaire and high strength, without sacrificing yield.
At a panel discussion at the recent Southeast Cotton Conference, representatives of Aventis, Delta and Pine Land Company, and Stoneville Pedigreed Seed, as well as specialists from North Carolina State University, outlined the focus toward fiber quality in recent years.
“During the past couple of years, there's been a shift in emphasis toward quality,” says Keith Edmisten, North Carolina State University Extension cotton specialist. “I think the seed companies have responded and you're going to see varieties that have improved fiber quality.”
It was only a few years ago when high micronaire readings created concern across the Cotton Belt. The cause: A large number of acres planted to varieties that had high yields and high mike readings.
Since genetics and environment affect fiber quality, seed companies and university researchers looked in both directions for answers. They found culprits in the backgrounds of varieties planted in large acreages across the Belt, and re-doubled efforts to close the gap between high yield and high mike. And they also found environmental solutions, such as defoliation timing, to lower micronaire readings.
Aventis has been at the forefront of providing varieties with a focus on both fiber quality and yields: So much so that some have labeled the FiberMax varieties as “Fake California,” a reference to the high-fiber quality produced in California.
FiberMax varieties — such as the full-season 989, the mid-season 966, and the early-season 958 — have “raised the bar for quality” in Virginia and North Carolina, says Jane Dever of Aventis. Gins have taken notice.
FiberMax 958, FiberMax 989 stacked and FiberMax 989 all ranked in the top two of variety trails in North Carolina and Virginia in regard to yield and fiber quality, Dever says. FiberMax 989 and FiberMax 966 will also be available in the Liberty cotton system in the future, with commercial quantities by 2004.
Experimental 0263 will offer a significant increase in fiber strength, as well as fusarium wilt tolerance.
“If you choose a variety that has good genetic potential for fiber length and you get in a drought during the critical bloom period, you have much less risk to drop below the discount range,” Dever says. “That is one reason I think that we should concentrate on developing very good fiber qualities in these varieties, no matter what the market says.”
“As long as you produce in the base range, you can grow all the cotton in the world,” says Dave Guthrie, manager of technical services with Stoneville Pedigreed Seed Co. “It's just when you come in with a 33 or below on length and above a 4.9 on micronaire that serious discounts kick in. Fiber quality is a component of value, but it's not the only component. You still need to pay attention to the total return on your investment.”
Stoneville Pedigreed Seed's recent purchase of the Helena and Germains germplasm is “meant to raise the overall level of fiber quality in our production line,” Guthrie says. Germains is noted for its premium mike, and high fiber strength and length varieties.
In the near future, Stoneville will have three releases that feature high yields and high fiber quality. One experimental line, X9905, is a stacked version of LA 887. ST 457 is a conventional variety with maturity similar to 474 and significantly improved fiber qualities. It consistently runs lower in mike and longer in length. ST 580 is a mid- to full-season variety that will have some role in North Carolina and farther south. “All of these varieties in university tests have yields as good as ST 474, and longer fiber length and reduced micronaire,” Guthrie says.
“The degree of importance of fiber quality is indicated because the entire industry is looking at the issue,” Guthrie says. “Stoneville has a commitment to fiber quality, so we can provide the cotton that the mills, the customer of the farmer's cotton, need.”
Developing solid conventional varieties is the aim at Delta and Pine Land Co., says Dru Rush. “We are developing conventional varieties and when these varieties have been through our testing regime…we'll introduce the transgenic traits, such as Roundup Ready, and Bollgard, into them. We are not breeding transgenic varieties.”
At seven locations in the United States, including two in the Southeast, and stations in Brazil and Australia, Delta and Pine Land Co. cotton breeders are looking toward a more diverse genetic base than in the past, Rush says.
Even with the next wave of technology such as molecular breeding and pollen transformation, the company plans to focus on genetics, yield, fiber quality suited to specific growing environments before introducing transgenics into proven varieties. “This gives us the flexibility to move the various traits into proven varieties as they become available,” Rush says.
Rush acknowledges the historical connection between high yield and increased micronaire, but points to recent breakthroughs at Delta and Pine Land Co. “Recently, we've been successful in avoiding that situation in some of our newer variety releases.” He points to Pearl, a variety that favorable compares with FiberMax 989. An early-season variety, 99MN03, a South American cross, will offer high yield, excellent strength and low mike for the upper Southeast. DPL 491 is a mid- to full-season variety with increased length and strength as well as lower mike. “DPL 491 is one of those breakthroughs that has increased yield and fiber quality,” Rush says.
DPL 555 BGRR, a variety which has a strong Australian fiber quality background, has shown tremendously high yields in four years of testing.
Defoliation timing is one way producers can affect micronaire, says Keith Edmisten, North Carolina State University Extension cotton specialist. “There are environmental effects for length, but they affect length less than micronaire.
“What we saw in the past was a tight fit between mike and staple,” Edmisten says. “Mike and staple would stay pretty close. We rushed into new varieties that we didn't have a lot of experience with and we saw a big separation in length and micronaire.”
Edmisten says it's important to think about how the boll develops. Roughly half of the boll development is spent elongating the fiber or making the length. The second half of develop is spent in thickening the fiber or the micronaire.
“Because length happens early, it's hard to have an effect on it with early defoliation,” Edmisten says. “You can have an effect on micronaire with early defoliation.
“If we could irrigate more cotton, we could have an effect on length and micronaire, too,” Edmisten says.
“To a North Carolina producer who can't irrigate, I'd advise putting the lower staple, high mike varieties on the better land where they're less likely to go into stress,” Edmisten says.
In their continuing search to advise producers on how to reduce micronaire readings, Edmisten and his colleagues last season looked at the effect of foliar application of potash on length. In most cases, it didn't have an effect on length, he says.