Pesticide use declined in California for a third consecutive year in 2008, according to Department of Pesticide Regulation Director Mary-Ann Warmerdam. Approximately 162 million pounds of reported pesticides were applied statewide, a decrease of nearly 10 million pounds – or 6 percent – from 2007.
Pesticide use in production agriculture fell by 9.6 million pounds and in most other categories as well, including structural pest control and landscape maintenance. Reports are mandatory for agricultural and pest control business applications, while most home, industrial and institutional uses are exempt.
“California experienced another dry winter and spring in 2008, which helps explain why fungicides showed the greatest decrease in use by both pounds and acres treated,” Warmerdam said. “Herbicide use also fell by pounds and acres treated, indicating fewer weeds.”
Insecticide use dropped by pounds applied, but grew slightly by acres treated, a change DPR scientists said reflected more growers shifting from broad-based insecticides to newer products more specific to the pest and less toxic to people and the environment.
Warmerdam emphasized that pesticide use varies from year to year depending on a number of factors, including weather, pest problems, economics and types of crops planted. Increases and decreases in pesticide use from one year to the next or in the span of a few years do not necessarily indicate a general trend.
Sulfur was again the most highly used pesticide in 2008 both in pounds applied and acres treated. It is a natural fungicide favored by both conventional and organic farmers used primarily to control powdery mildew on grapes and processing tomatoes. By pounds, sulfur accounted for 25 percent of all reported pesticide use. Its use decreased by 5.7 million pounds – or 12 percent – from 2007 to 2008 and accounted for most of the reduction in reported pesticides.
The pesticide with the greatest rise in pounds applied was the fumigant potassium n-methyldithiocarbamate, also called metam-potassium, which increased by 1.7 million pounds, or 45 percent. It was used primarily as a replacement for other fumigants used to treat soil for growing tomatoes and carrots.
Major crops or uses that showed an overall increase in pounds of pesticides applied included carrots, processing tomatoes, fresh market tomatoes, tangerines and public health purposes such as mosquito control. The data showed a decrease in pounds applied to wine grapes, table and raisin grapes, cotton, lumber and oranges.
The top five counties in order of most pesticide pounds applied in 2008 were Fresno, Kern, Tulare, Monterey and Madera. All are major producers of agricultural products.
Other details from DPR’s 2008 pesticide report that compares 2007 and 2008 data:
● Use of organophosphate and carbamate pesticides – most of which are older compounds of high regulatory concern because of their toxicity and detection in surface water – continued to decline. In 2008, their use dropped by 720,000 pounds and 590,000 acres treated, or 12 percent.
● Use of chemicals classified as reproductive toxins declined by 1.7 million pounds and 182,000 acres treated, or 10 percent. These chemicals are used on a variety crops.
● Use of chemicals classified as probable or known carcinogens declined by 1.7 million pounds and 600,000 acres treated, or 7 percent and 17 percent, respectively. These chemicals are used on a variety crops.
● Use of chemicals classified as toxic air contaminants, another category of regulatory concern, declined by 50,000 pounds and 370,000 acres treated, or 0.13 percent and 12 percent, respectively. These chemicals are used on a variety crops.
● Use of most chemicals classified as groundwater contaminants declined by 270,000 pounds and 300,000 acres treated, or 17 percent and 25 percent, respectively. These chemicals are used on a variety crops.
● Use of oil pesticides declined by 214,000 pounds, or less than 1 percent, but increased by 100,000 acres treated, or 3 percent. Most oils serve as an alternative to highly toxic pesticides and are used by organic farmers.
● Pounds of fumigants applied increased slightly by 228,000 pounds, or 0.6 percent, but decreased by 3,100 acres treated, or 0.9 percent. Fumigants are gaseous pesticides that farmers mostly use before planting to control disease, weeds and pests in the soil. They are primarily used on strawberry, carrot and processing tomato fields. Fumigants are also used for structural pest control.
DPR has the most extensive pesticide use reporting system in the United States and supports one of the most comprehensive pesticide regulatory programs in the world. These data support a variety of regulatory efforts, including compliance efforts for clean air and water laws, estimating dietary risks, protecting workers in the field, preserving endangered species, assisting product registration and review and helping local pesticide law enforcement.
One of five departments and boards within the California Environmental Protection Agency, DPR regulates the sale and use of pesticides to protect people and the environment.