Environmental stresses of the last few years have been tough on cotton varieties and their reputations. Yet at least one seed line appears to have handled the stresses quite well in a limited scope. While Aventis FiberMax varieties have yet to pass the test of time over a larger expanse, the question begs to be answered, “Why?”

According to Jane Dever, cotton breeding and product development manager for Aventis, the story begins Down Under.

That's where cotton lines were selected which led to the development of five current FiberMax conventional picker varieties and four transgenic picker varieties. The original lines were developed by Australia's Commonwealth Scientific Industrial Research Organization (CSIRO) and selected by ACSI (joint venture breeding program of Aventis and Cotton Seed International) for production conditions in the United States.

Characteristics of the original lines, and still retained by their derivatives, reflect Australia's distinct breeding philosophy, noted Dever.

“The export market for Australia demands very good fiber, so excellent fiber characteristics are a high-priority objective in the breeding programs,” Dever said. “And good yield potential is necessary because of high-input production conditions.

“Admittedly, the U.S. market rewards yield over fiber, and input costs vary widely across the Belt,” she said. “Early maturity, to lower input costs, has high priority in the U.S., while fiber quality may have lower priority.”

In essence, “the fact that the demands of the Australian cotton industry made fiber quality a very high priority in the breeding program has been a benefit of the FM varieties for U.S. growers.”

A big challenge for Aventis/FiberMax is adapting Australian lines to U.S. growing regions. They're continuing to make significant progress.

Three strains developed in the ACSI program at Mississippi by Jeff Gwyn were entered into state official variety trials in 2000. Noted Dever, “These potential varieties in our pipeline, averaged over nine locations, had yield increases of 16, 12 and 11 percent over the most widely grown competitive variety in the Delta and yield increases of 9, 5 and 4 percent over FM (FiberMax) 966.

“Fiber length was 1.11, 1.10 and 1.11 compared to the ST 474 at 1.05; strength of 30, 26 and 36 compared to 27 and micronaire of 4.4, 4.3 and 4.4 compared to 4.8. We feel that our pipeline can only improve with local breeding, and it is significant that we are starting with germplasm that underwent heavy selection pressure for fiber quality.”

What does this higher quality mean to growers? Dever says that mills and merchants searching for bales with certain specifications can improve their efficiency by buying from grower associations that pool bales of similar quality.

“Since FiberMax varieties normally produce fiber length and strength above the crop average, and micronaire in a desirable range, growers can improve the probability of meeting contract specifications at the end of the season,” Dever said. (FiberMax growers who participate in marketing associations or pools do it at their own discretion, outside the influence of Aventis).

FiberMax cotton varieties were unveiled during a time of extreme environmental stress in the Cotton Belt, yet stood out in both yield and quality while many other cotton varieties took a hit in those areas.

As to the latter, Dever points out that herbicide-tolerance and insect-resistance are very strong components of variety acceptance among growers. “But these important improvements in cotton varieties did not necessarily mean simultaneous improvement in yield and quality. Some of the new varieties have given existing germplasm a market life longer than the traditional 8-10 year life cycle of a conventional variety.”

Dever says that FiberMax varieties represent a whole new germplasm base for U.S. cotton producers and are now combined with equally exciting new technology — Aventis recently reached an agreement with Monsanto in March to introduce Roundup Ready and Bollgard traits in FiberMax cottons.

While she cautions that FiberMax varieties have been planted only since 1998, and average yield and quality trends should be looked at long term, there is promise.

“What is evident in state trials and production bales is that fiber produced from FiberMax varieties shows improvement relative to current crop averages in length, strength, micronaire and uniformity. FM 958 and FM 966 have improvements in the yield component of weight fiber/seed — an important indication of yield stability.”

If FiberMax varieties performed well in heat and drought, will they do even better when conditions are more favorable?

“All FiberMax varieties are different and should be produced where they have the best agronomic potential,” Dever stresses. “FM 832 has performed well in stress conditions in South Texas relative to other varieties, but was not as well adapted to the high fertility, good moisture conditions in the Southeast and Mid-South. However, we have had very good performance of FM 832 in Louisiana and South Texas.

“Conversely, FM 989 performs well relative to competitive varieties in favorable conditions. In regard to relative performance, each variety has its own ‘favorable conditions.’”

And as cotton producers are all painfully aware, favorable conditions are not necessarily geographically specific.

For example, FM 989 was planted to significant conventional acres in North Carolina in 1999 because of its excellent performance in the state trials. “Hurricanes in 1999 came through at a time that was more detrimental to FM 989 than the early-maturing varieties. Our acreage decreased, but the variety continues to be a good performer there. The introduction of FM 958 was timely as it offered earlier maturity with the same fiber quality package.”

FiberMax varieties have wide acceptance in Texas, comprising 55 percent of the South Texas crop, according to USDA. “South Texas had enjoyed an advantage in the market because of their early harvest,” Dever said. “That advantage had dissipated over the years because the better yielding varieties for that area had less than optimal fiber properties. When FM 832 was introduced, and offered yield, quality and stress tolerance, grower acceptance was very quick.

Two new varieties, FM 958 and FM 966, were recently released for the Mid-South region. Currently, the germplasm is available only in conventional varieties.

According to Dever, the two varieties performed very well in state trials in Tennessee, Arkansas, Missouri and Mississippi. “They have the earlier maturity that we need for this region. In the state trials where yield was very good, these varieties also produced some of the longest and strongest fiber in the tests. In the Tennessee cotton variety test results in 2000, two varieties with high fiber strength and long staple length, FM 958 and FM 966, also had the highest mean yields across locations.”

FiberMax varieties with Bollgard and Roundup Ready genes, “will go a long way toward addressing many grower needs, including profitability,” Dever said. “The addition of Liberty and Buctril herbicide resistance will offer a good range of management options.”

Tests conducted in the United States in 2000 indicate that FiberMax transgenic varieties are similar in yield potential and maturity to their recurrent conventional parents with equivalent fiber characteristics.