It's sulfur season, but don't be alarmed.

Anyone in Lodi who lives or drives near vineyards is likely to see sulfur or hear it being applied these days.

Agricultural sulfur is critical to the production of premium wine grapes, and the fine, whitish powder is used almost universally by growers to prevent the onset of mildew during warm-weather months.

Some new area residents not familiar with agriculture fear the fluffy white powder, mistaking it for a toxic substance.

Others, who elected to purchase homes near vineyards, are disturbed by the seasonal noise and smell of the applications.

Now, a campaign is underway to educate growers about a set of application techniques that are less annoying to neighbors - and more cost-effective.

Sulfur has a surprisingly interesting place in history.

It was the first pesticide discovered by mankind, used in the vineyards of Persia more than 2,000 years ago to stop mildew.

Gladiators used it as an antibiotic to heal the gaping wounds suffered in the fierce combat of the Roman coliseum.

Local grape growers are quick to tell you the benign, chalky powder kicks up quite a fuss every spring when they start applying it to their vines.

"Every year, somebody rides or walks past a cloud of sulfur, and they're sure they've been poisoned," Lodi grape grower David Lucas said.

Pesticide experts agree that sulfur is the safest material available to combat mildew and point out that it is harmless enough to have been certified by the state for use in organic farming.

Despite the fact that most growers observe the rules of common courtesy and common sense when dusting their vines, the growing clash between agriculture and urban sprawl has added dramatically to complaints from the public in recent years, Lucas said.

"We want to educate people who are fearful that they're being exposed to some kind of toxic substance," he said. "Any time you see dusting going on, it's sulfur. Nothing else is applied that way."

Nonetheless, complaints come rolling in every year - usually before the dust has settled from the first wave of applications in early April.

"We get a number of complaints each year," said San Joaquin County Agricultural Commissioner Scott Hudson, who added that those complaints invariably take one of three common forms.

First are complaints from people who have been exposed to sulfur drift and are concerned about what the substance may be - and whether or not it is toxic, Hudson said.

"Once I explain what it is, that usually puts their mind at ease," he said, adding that each complaint received by his office is thoroughly investigated.

Next come people who suffer from allergies, whose condition is exacerbated by sulfur dust.

Third are people who don't want mystery dust on their car or in their swimming pool - toxic or not, Hudson said.

His office has received 16 formal complaints about sulfur drift in the past three years.

Hudson was unaware of any complaints so far this year.

"But they haven't been dusting very long yet," he said.

No permit is required to apply sulfur in vineyards, but under state law, fines for its improper application can run as high as $1,000 per violation, Hudson said. However, such fines are extremely rare, he said.

Spurred by concerns from within the agricultural sulfur industry, the state department of pesticide control formed an alliance three years ago to formulate a comprehensive pest management strategy for vineyards.

Doug Okamura of the state department of pesticide control said the alliance, comprised of sulfur producers and members of the agricultural community, was formed in response to a rash of complaints in Madera County involving school buses.

The alliance cobbled together a guideline which includes such information as the best times and methods of application, along with the most low-drift methods for applying sulfur in vineyards, Okamura said.

"I was impressed with both what they accomplished and how fast they accomplished it," he said. "I've rarely seen this kind of effort before."

Members of Lodi's wine industry formed a local task force in July 2000. Among that group is Lodi vineyard expert Cliff Ohmart, who holds a doctorate in viticulture from the University of California, Davis.

Sulfur is the safest, most cost-effective material available for the control of mildew in vineyards, Ohmart said.

"There are a couple of man-made products out there," he said. "But nothing is as effective as pure, elemental sulfur. Grape growers simply couldn't function without it."

And unlike with the synthetically created materials, mildew is unable to develop a genetic immunity to the effects of sulfur, Ohmart said.

"The funny part is, we still don't understand the specific biological mechanism that makes sulfur so effective. We just know that it works."

Typically, sulfur is applied to vineyards from early April until the end of June, when grapes contain enough sugar that they are no longer vulnerable to mildew.

Growers apply sulfur as needed every six to 14 days, Ohmart said. The "popcorn" sulfur used by farmers - so named because of its strange resemblance to the ubiquitous snack - costs about $8 for a 50-pound bag. It takes between 10 pounds and 15 pounds per acre to treat grape vines, Ohmart said.

Local growers are confident that the grassroots effort to inform growers about the best techniques for applying sulfur will pay off in the end.

"This is a very important issue for us because without sulfur we would effectively be out of business," Lucas said.

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