Pesticide use in Merced County is on the rise, according to the annual report from the California Department of Pesticide Regulation.
The bump followed a statewide trend that saw an increase in pesticide use after four years of decline.
Merced County now ranks as the seventh-highest user of pesticides in the state. According to the most recent statistics, in 2010, the county applied more than 7.7 million pounds of pesticide, an increase of just less than 2 million pounds from 2009.
The levels of pesticides farmers use are significantly affected by weather conditions, among other factors. According to the state, 2009 and 2010 were relatively cool and wet years, conditions that can increase mildew and other problems treated with chemicals.
The trend continued this year for Scott Hunter of Hunter Farms, who looks after more than 1,400 acres of almond trees. He said applying pesticides is a last resort.
"It takes a lot of manpower and costs money," he said. "This year, because of the wet spring, I had to apply extra fungicide spray. I had three extra sprays I had to put on because of weather conditions."
The type of crops that farmers choose to grow also can affect pesticide use. In Merced County, almond farmers applied the most pesticide, mainly because they use the most acreage. But sweet potato farmers, by far, used the most pesticide per acre, according to state statistics.
Almonds were among a number of crops that saw an increase in pounds of pesticide applied, including wine grapes, carrots and cotton. Crops such as rice, processing tomatoes and alfalfa saw a decline in pesticide applied.
Many farmers weren't only spraying more intensely, they were treating more acreage. From 2009 to 2010, acreage treated with pesticide statewide increased by 9.7 million acres, or 15 percent, to 75 million acres treated, according to state regulators.
In Merced County, the number of acres treated with pesticide increased from roughly 3 million in 2009 to more than 4 million in 2010, an increase of close to 1.2 million acres.
Paul Towers, a spokesman for the Pesticide Action Network, a nonprofit advocacy group, said the state could more safely handle such increases in agricultural production if pesticide alternatives were pursued and embraced.
"California is stuck on a pesticide treadmill," he said. "State officials should take necessary steps to take these products off the shelf while providing research training and support for greener, healthier alternatives."
Although many pesticides come with limits on local use and strict permitting processes, use of several chemical fumigants, which worry environmentalists, have substantially increased.
Dichloropropene, a fumigant commonly used on almonds and sweet potatoes, shot up by 2.4 million pounds, or 37 percent. Metam-sodium and metam-potassium also have increase in use.
Many farmers have rushed to use these fumigants as once-popular methyl bromide continues to be phased out under an international treaty to protect the ozone layer.
"Many pesticide manufactures and biotech (companies) have convinced rural communities that we need to continue to use these outdated practices," Towers said. "We need to break through this wall of misinformation."
However, the idea that alternatives to pesticides, and specifically fumigants, aren't being pursued is false, said Maxwell Norton, a scientist at the University of California Cooperative Extension in Merced.
"Pest management has more resources dedicated to it than any other field of agriculture research," he said. "Agricultural researchers are putting a lot of resources into alternative systems. The research reports are there in the hundreds for people to read. We will eventually come up with alternatives."
In 2010, the San Joaquin Valley was the biggest user of pesticide in California. The counties of Fresno, Kern, Tulare, San Joaquin and Madera topped the list.
Reporter Joshua Emerson Smith can be reached at (209) 385-2486 or firstname.lastname@example.org.