San Francisco Chronicle

Pesticides hinder pot crops’ move to farmland

- By Jackie Flynn

California’s recreation­al pot market begins commercial licensing in January, and industry leaders have long expected cannabis farms to go from clandestin­e to convention­al.

That means abandoning the steep hills in the remote mountains of Humboldt and Mendocino counties for the traditiona­l agricultur­al lands in the Central Valley. There, the ground is flat and connection­s to city markets are abundant.

But one large obstacle to such a move looms: the rampant pesticide use across California’s farmlands. With the state’s de facto organic standards for legal cannabis, it could mean the best place for pot farmers is the wildlands where they started.

“We won’t be able to grow cannabis next to traditiona­l, full-scale agricultur­e. It just won’t be practical,” said Hezekiah Allen,

executive director of the California Growers Associatio­n. “I live in Yolo County. I see the crop dusters. It’s not going to work.”

“This is going to lead to huge conflicts,” said Chris Van Hook, director of Clean Green Certified, a sustainabl­e cannabis certificat­ion program that operates in place of the U.S. Department of Agricultur­e’s organic program. “We have had farmers who have had their entire year’s crop rejected because they were next to a blueberry field.”

For Steve DeAngelo, 59, executive director of Harborside Farms, broccoli was the likely culprit in a similar contaminat­ion. DeAngelo was one of the first large-scale pot farmers to set up shop in one of California’s most productive farmlands — the Salinas Valley.

In 2016, he establishe­d 200,000 square feet of cannabis greenhouse­s and grew weed following organic standards, but the farm’s first harvest failed testing due to pesticides — chemicals he said he never applied. He suspected contaminat­ion by pesticides blown over from crop dusters on a neighborin­g broccoli farm.

Pesticide drift is rampant in modern agricultur­e. According to a 2016 review in the journal Comprehens­ive Analytical Chemistry, up to 30 percent of pesticides sprayed on crops don’t end up where they’re supposed to.

“If you looked at a map of agricultur­e in the Central Valley, just the sheer concentrat­ion of industrial farming — you’d see the problem immediatel­y,” said Dominic Corva, founder and social science research director at the Center for the Study of Cannabis and Social Policy, a nonprofit based in Seattle.

Farmers in California’s Central Valley, the state’s largest agricultur­al region, applied more than 150 million total pounds of pesticides to crops in 2015 (the most recent year data are available). That’s an average of 3,500 pounds per square mile and makes up more than 75 percent of all pesticides applied across the state, according to data from the California Department of Pesticide Regulation.

Meanwhile, state pot regulators plan to set contaminat­ion failure levels in the ranges of a few parts per million. Because scientists generally don’t know the risks of inhaling burned pesticides, the state has proposed some of the country’s tightest limits on more than 60 popular cannabis pesticides.

“Unlike agricultur­al crops, when it comes to cannabis goods, scientists have rather limited knowledge of how much an average person may ingest or inhale or use a cannabis product on a daily basis,” said Charlotte Fadipe, assistant director of California’s Department of Pesticide Regulation, in an email.

One pesticide threatens cannabis growers more often than any other. Farmers apply myclobutan­il — often called Eagle 20 — to a variety of crops to prevent powdery mildew. Myclobutan­il isn’t deemed harmful if eaten, but if smoked, myclobutan­il turns into cyanide gas, which could be dangerous. Thus, regulators have proposed limiting myclobutan­il on cannabis to levels that are as little as one five-hundredth of what’s allowed on other crops.

Pesticides drifting over from a convention­al farm to a cannabis farm are only part of the problem. When farmers spray pesticides as well as residual pesticides in soil and water are also major problems for pot growers eyeing regular farmland.

In the Central Valley, farmers spray pesticides on almonds and stone fruit just before the fall pot harvest, the “exact worst time for cannabis,” Allen said.

“This is a delicate flower,” said Swami Chaitanya, of Mendocino County’s Swami Select Cannabis. “If you’re going to spray Eagle 20 on this, you’re never going to get it off.”

And pesticides don’t break down easily in the environmen­t. Some can persist in soils for up to 20 years, according to Reggie Gaudino, vice president for scientific operations and director of intellectu­al property at Steep Hill Labs, a cannabis testing facility based in Berkeley.

“The dirtier or more agricultur­ally inclined a place is, the more pesticides will get into the water,” he said. These hidden pesticides can be taken up by cannabis, a plant that is naturally good at pulling chemicals out of the environmen­t.

At Harborside Farms, DeAngelo did two major things to prevent contaminat­ion. First, the farm began growing weed from seed, rather than buy cuttings, which are often dipped in pesticides. Second, Harborside installed enormous ventilatio­n systems to push filtered air through its greenhouse­s and keep pesticides from drifting in.

It worked. After six months of transition time, Harborside Farms grew contaminan­t-free cannabis.

“It is not impossible for convention­al agricultur­e and organic cannabis to co-exist,” said DeAngelo.“We’re doing it now. I just harvested 2,000 pounds of clean cannabis.”

But DeAngelo said his farm has resources smaller farms don’t, including fulltime lawyers to talk to neighbors and county regulators.

Even with tight pesticide rules, there should be enough clean cannabis for all of California’s consumers — eventually. California­ns use about 2.5 million pounds of cannabis annually, while the state produces an 11 million-pound surplus for export.

“We have no problem producing clean cannabis in California. We just need to make sure it’s that cannabis that gets on the shelves,” Allen said. “At the end of the day, these are the best practices.”

Van Hook said the industry’s pesticide struggles should yield new solutions for other crops.

“There will be agitation and conflict, but we’re moving toward cleaner practices,” he said. “Hopefully five to 10 years from now, it will lead to safer pesticides and safer applicatio­n.”

 ?? Michael Macor / The Chronicle ?? Chris Van Hook (left), director of the Clean Green Certified program, meets with Swami Chaitanya and Nikki Lastreto before inspecting their cannabis farm in Mendocino County.
Michael Macor / The Chronicle Chris Van Hook (left), director of the Clean Green Certified program, meets with Swami Chaitanya and Nikki Lastreto before inspecting their cannabis farm in Mendocino County.

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