SJV whitefly stickiness report card due

San Joaquin Valley cotton producers, pest control advisers and an army of supporting cast members have taken the final exam for Sticky Cotton Prevention 101.

Final grades are not in yet. However, no one will pass. There will be sticky cotton bales from the 2002 SJV cotton crop, but certainly not as much as could have been before the industry and its leaders faced head on an issue that threatened to bring down the much-touted SJV quality cotton industry.

Following the 2001 crop when textile mills complained loudly about sticky SJV cotton, industry leaders decided not to ignore the problem in hopes it would go away. That was tried in the past. Not this time. Earl Williams, president and CEO of the California Cotton Ginners and Growers Association, led a massive public relations and educational effort to convince producers to control honeydew-excreting insects like the silverleaf whitefly to prevent sticky cotton.

“The jury is still out,” proclaimed Williams at a recent meeting in Tulare to look back on 2002. “There is still a lot of cotton to ship to textile mills, but merchants say so far stickiness is way down from last year.”

Supima Association of America president Jesse Curlee says mills are looking for stickiness, too. He made late December trips to mills in Japan, Thailand and Hong Kong and heard no lint stickiness complaints from the early 2002 shipments.

“And, they were looking awfully hard. There is still not a lot of new crop in the mills yet, but what they received they checked pretty quick” to see if they could expect a repeat of 2001.

Somewhat relieved

“So far, so good,” he said. Curlee is somewhat relieved since by mid-summer reports were circulating that some producers were doing nothing to control whitefly to keep from spending money.

Williams and University of California integrated pest management specialist Pete Goodell acknowledge there apparently where producers who did nothing last season to mitigate stickiness-causing whitefly populations.

“Nevertheless, we have made serious progress in addressing this serious issue,” said Williams. “We know that one year” of education and public relations “will not solve the problem.”

Williams pledges to continue preaching the “No Sticky Cotton” gospel. He also is campaigning to make measuring for stickiness part of the USDA cotton classing process. Right now there is a zero stickiness tolerance. That may not be necessary, he said.

However, that is a peripheral issue to the more pressing issue importance of controlling stickiness-producing whitefly.

Whitefly were heavy last season. Maybe not as heavy as 2001, but certainly the No. 1 pest in the valley.

“I have seen more whitefly in the past two years than I have had in the previous 20,” said Los Banos, Calif., consultant Mark Carter who works primarily on the West side of the San Joaquin Valley.

Light insect year

“Last season was a very light pest year for the typical cotton pests — spider mites, lygus and aphids. “Whitefly was the most serious pest growers and pest control advisers faced. It did require management to produce a quality crop. I am not sure I'd call it a severe whitefly problem, but there were areas where doing nothing created sticky cotton.”

That was true for primarily the southern portion for the valley: Kern, Kings, eastern Tulare and for the first time western Fresno County where whitefly is typically a problem. The California Department of Food and Agriculture's pink bollworm program monitored whitefly levels as part of its PBW trapping program last season and confirmed that the whitefly continues to move north.

“There were places where growers did not have to do anything and still produced clean cotton. Others treated once with an insect growth regulator and controlled whitefly for the season. Others still treated more than once, at very low threshold levels over a wide area to preclude any chance of stickiness.

When the all-out assault was declared on the problem, California turned to Arizona for control strategies. In the early ‘90s, Arizona's cotton industry was brought to its knees by the same pest, but now the stickiness issue is past thanks to extensive research and subsequent control efforts, primarily relying on a pair of insect growth regulators, Knack and Courier (formerly called Applaud.)

Good Arizona job

Arizona has done such good job that last season Arizona short staple cotton was sought by mills as replacement for sticky SJV cotton.

Not unexpectedly, the cookie cutter approach did not work exactly.

Goodell said Arizona entomologists were not surprised at the differences discovered in 2001 between SJV whiteflies and Arizona whiteflies.

Nevertheless, Goodell said the Arizona models are the best available and he was glad they were available to California in a time of crisis. The role now is to tweak the Arizona system to fit SJV conditions.

“In Arizona it seems if they can control the incipient whitefly population in a field with the IGRs, they can delay on outbreak for weeks — until defoliation where they can use a pyrethroids to kill adults,” said Goodell.

That does not seem to be the case in California where populations seem to build earlier. “We are getting adults on a regular basis after mid-July in higher numbers than in Arizona,” said Goodell. There also seems to be a higher reproductive rate of whiteflies in cooler California.

“Some California pest control advisers think the Arizona model is triggering treatments too early,” added Goodell.

Some contend that the greater crop diversity in the San Joaquin makes whitefly more plentiful by migration among crops.

“I don't think we have to re-invent the wheel based on what we saw last year. We don't have the time or resources for that,” said Goodell. “What you have to remember we never had the opportunity to validate the Arizona model in California until we started advocating it valleywide.”

Pressure too great

King County UC farm advisor Bruce Roberts said whitefly pressures are too great in California to start over. “What we have to do is validate what works to control whitefly and what does not under a wide array of conditions,” he said.

“In 2001 when we had the big problem was unique. 9-11 grounded planes and the economics were so bad with cotton there was no money to treat for insects,” Roberts said. That was not the case last season.

Roberts said a variety of things came together in 2002 to address the problem. Raising the awareness level was the first step. CDFA sampling for whitefly helped identify problem areas and will be critical in managing whitefly levels on a regional basis.

“CDFA's information is vital in identifying where problems may be surfacing during the season,” said Roberts.

The San Joaquin Valley Cotton Board joined the anti-stickiness army by asking Shane Ball, University of California cotton specialist who manages its variety evaluations, to also monitor lint stickiness.

Last year Ball reported a dramatic drop in overall stickiness; 46 percent less in Acalas and 75 percent less in Pimas than the year before.

However, his data also showed dramatic ranges of lint stickiness by testing location and by variety within locations.

Although lint stickiness problems in mills has been traced mostly to whitefly-secreted honeydew, there are other factors that may come into play, like natural plant sugars, according to Roberts.

High natural sugar

“If there are varieties that have high natural sugar levels that could be a factor in heavy whitefly pressure situation, growers may want to avoid those varieties if they expect a whitefly problem in a specific location,” said Roberts.

“The information Shane has developed is another critical element in the total complex issue of dealing with silverleaf whitefly and stickiness,” said Roberts.

Roberts said one of the most perplexing entomological issues surrounding whitefly is the role lygus — more specifically, the lack of lygus — plays in the whitefly-stickiness problem.

“The lack of lygus over the past two years has helped us achieve significant yields in the valley yet whitefly pressure has been heavy those same two years,” said Roberts. “The whitefly and lygus are two different critters, yet the question is have we been suppressing whitefly when we have to treat for lygus.”

Questions on table

That is just one of the many questions still on the table in the all-out war declared on the whitefly and sticky cotton in the San Joaquin Valley. It is a brand new era for valley producers that will continue from now on.

Goodell said the stickiness controversy has moved cotton into the produce world where appearance and quality are paramount.

“To make sure SJV cotton stays in the game we have to prove we can deliver quality cotton fiber,” said Goodell.

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