Farm Progress

California is facing a sticky cotton problem that has been triggered this year by the worst whitefly infestation in more than a decade.

Dennis Pollock 1

October 2, 2013

5 Min Read
Larry Godfrey, right, entomologist with the University of California at Davis, with Mike Davis, professor of plant pathology at UC Davis, who is flanked by graduate students Amanda Cianchetta and Hung Doan.

With retirement just months away, longtime California cotton industry leader Earl Williams gave heartfelt thanks to researchers who say they could be as close as two years from development of cotton varieties that are resistant to a problem that has nagged the state for about two decades, Fusarium Race 4.

Williams, president and CEO of CaliforniaCotton Growers and Ginners Associations, then proceeded to deliver frank and impassioned concerns about another problem facing the state’s industry this year: “sticky cotton.”

As pleased as Williams was about progress being made in the battle against Fusarium, which he said has been “the No. 1 enemy” of California cotton, he appeared just as concerned about the sticky cotton issue that has been triggered this year by the worst whitefly infestation in more than a decade.

Sticky cotton results from honeydew secreted by white flies and cotton aphids.

Williams warned that sticky cotton can sour markets in the U.S. and abroad.

“When we had sticky cotton in a few areas last year, we had one of the largest mills in China that registered complaints,” he said.

He urged cooperation among all of cotton’s players to address the issue.

“We need cooperation from growers,” Williams said, “We need cooperation from (pest control advisors). We need cooperation from the ginners who are going to be ginning this crop. We need cooperation from the merchant community that’s going to be putting this crop into channels around the world. Our reputation is dependent upon it.”

Williams said the stakes are even higher today, given that the total acreage of cotton in California has dwindled to 275,000 acres from the more than 1 million acres it once covered.

“It’s more important to protect markets,” Williams said. “The smaller the crop, the bigger the microscope.”

Williams and others said there is still time to address the issue, given that the cotton harvest is several weeks away.

One way to address it is to spray before picking.

Among those addressing Williams and others for a cotton research update was Steve Wright, a University of California farm advisor for Tulare and Kings Counties. He said harvest preparation this year can include spraying for the pest at the same time defoliants are applied.

A report presented to participants in the Five Points field day at the California West Side Research and Extension Center stated: “There may be advantages to stepping up the timing of harvest aid application to start the process of removing leaves that encourage continuing population of whitefly and perhaps aphids. If you are not likely to gain a large amount of yield waiting for very late bolls on the plants, the advantages of limited whitefly populations and sticky cotton potential likely outweigh the value of yield gains.”

Resistant varieties

Wright said growers still need to take into account that the best conditions for effective defoliation come during moderate to high air temperatures, relatively low plant and soil nitrogen levels, moderate soil water levels and times when there is uniform crop development.

The first mention of the whitefly issue came from Larry Godfrey, entomologist with the University of California at Davis, who said aphids and leafhoppers have also been a problem.

Godfrey warned that the industry could see its arsenal of pesticides weakened with additional restrictions on older classes of chemistries such as organophosphates, coupled with some restrictions resulting from efforts to protect bee populations.

The good news on development of resistant varieties came mostly from Mauricio Ulloa, with the U.S. Department of Agriculture’s Agricultural Research Service in Lubbock, Tex., and Allen Van Deynze, a professional researcher at the Seed Biotechnology Center at University of California, Davis.

Van Deynze said developments in use of cotton genetics mean that it does not take six generations to develop a new variety. A single generation can give “a pure breeding line,” thanks to breakthroughs in understanding of markers and sequencing.

Ulloa said researchers have identified 150 markers for disease resistance and he and others said PhytoGen could be within two years of releasing Fusarium resistant varieties for commercial growers.

Williams said he was “leaving this meeting proud and encouraged that we are on the cusp of a real answer and a solution to this problem.”

There was still other good news out of the meeting.

Larry Olagues, agricultural pest control supervisor for the California Department of Food and Agriculture’s Pink Bollworm Program, said this was the second year when there have been no finds of the bollworm in California.

That’s the first time in the 45-year span of the program in which there have been two consecutive years of no finds.

“We’re halfway to eradication,” Olagues said, noting that four consecutive years of no bollworm finds would amount to the eradication designation.

And Pete Goodell, UC integrated pest management advisor, said a breakthrough may be near on development of a sex pheromone for use to draw lygus bugs.

Goodell said lures for pheromone-baited traps could be part of “an early warning system” that could help in proper timing of sprays for the pest.

He said “world class chemistry” is being used to develop the traps, and one of the researchers who have been a key in their development is David Hall, with the Natural Resources Institute in Greenwich University, England.

The traps are already being used for early detection in fruit orchards in England.

Now the challenge is to come up with the right blend of volatiles that will attract the female lygus, and traps are being tested successfully in alfalfa at the Kearney Ag Center in Parlier. Goodell said testing of traps will likely begin in cotton next year.

“The ability to detect the first lygus arriving in an area could improve our decision-making, timing and choice of insecticides as well as improving our understanding of regional population development,” Goodell said.


Sticky cotton


Bob and Steve; Bob Hutmacher, left, University of California Cooperative Extension specialist, and Steve Wright, a UC farm advisor for Tulare and Kings Counties.

Don and Earl: Don Cameron, left, a Fresno County cotton grower and chair of the California Cotton Alliance, and Earl Williams, president and CEO of CaliforniaCotton Growers and Ginners Associations.



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