- Author: Jeannette E. Warnert
A critical part of the workshops is the U.S. Environmental Protection Agency's proposal to cancel the pesticide chlorpyrifos in agricultural production. EPA is accepting public comment on the proposal until Jan. 5.
Chlorpyrifos is a widely used pesticide and part of integrated pest management in many crops. Under the trade names Lorsban, Lock-on and in generic formulations, chlorpyrifos is used to control ants, stink bugs, aphids, whiteflies and other pests. A 2014 report coordinated by the UC ANR Statewide Integrated Pest Management Program concluded the pesticide is an important tool for California producers of alfalfa, almonds, citrus and cotton.
At the workshops, growers, pest control advisors, UC scientists, state and local regulators and members of the local agricultural community will discuss chlorpyrifos permit conditions and the proposed regulations as well as IPM approaches to managing critical pests.
New decision-making tools for insecticide recommendations and stewardship activities will be shared. Industry members will also have the opportunity to provide input to the California Department of Pesticide Regulation and other regulatory officials about the use of chlorpyrifos in their IPM systems.
Meeting dates, times and locations are as follows:
Jan. 7 – Almonds Central San Joaquin Valley
8 a.m. to 12:30 p.m.
UC Kearney Agricultural Research and Extension Center, 9240 S. Riverbend Ave., Parlier
Jan. 8 - Alfalfa and field crops in San Joaquin Valley
8 a.m. to 12:00 p.m.
Cabral Center, 2101 E. Earhart Ave., Stockton
Jan. 12 – Citrus in San Joaquin Valley
8 a.m. to 12:00 p.m.
UC ANR Cooperative Extension office, 4437 S. Laspina St., Tulare
Jan. 21 – Alfalfa in Imperial Valley
8 a.m. to 12:00 p.m.
Farm Credit Services Southwest, 485 Business Parkway, Imperial
Jan. 26 – Almonds in Southern San Joaquin Valley
8 a.m. to 2:30 p.m.
Kern County Agricultural Pavilion
3300 E. Belle Terrace, Bakersfield
Feb. 5 – Almonds in Northern California
8 a.m. to 12:00 p.m
Chico Masonic Lodge, 1110 W. East Ave., Chico
Pest control advisers will receive continuing education credit. For more information contact Lori Berger, UC IPM chlorpyrifos project coordinator, at firstname.lastname@example.org or (559) 646-6523.
An initiative to manage endemic and invasive pests and diseases is part of UC Agriculture and Natural Resources Strategic Vision 2025.
The intensive, hands-on workshop will be led by Ken Giles, professor in the Department of Biological and Agricultural Engineering at UC Davis; Franz Niederholzer, UC ANR Cooperative Extension advisor for Colusa, Sutter and Yuba counties; and Lynn Wunderlich, UC ANR Cooperative Extension advisor for the Central Sierra region.
The UC ANR instructors will train participants to identify the appropriate spray equipment components, practices and conditions necessary to deliver safe and effective agricultural pest control to a particular location, timing and crop.
The workshop will cover nozzles and atomization, the dynamics of drift and how spray droplets move, factors affecting spray deposition, hydraulic nozzle alternatives (electrostatic, air shear, etc.), measuring spray coverage, pumps, sprayer selection, air-assisted spraying and more.
Before the class, to fully prepare, registrants should view a short, online PowerPoint presentation about basic sprayer calibration. A link to the PowerPoint will be sent in the registration confirmation email. A brief quiz on the material will be given at the beginning of class on Sept. 22.
The training is set to begin at 12 noon on Sept. 22, resuming at 8 a.m. on Sept. 23 and end at 2 p.m.
Registration for the training costs $150 until Sept. 12 and $175 after Sept. 12 and can be paid online at the registration website. Onsite registration will cost $200. The organizers have applied for CDPR Continuing Education units.
To register or to get more information, visit http://ucanr.edu/sites/Spray_Application_Training.
- Author: Jeannette E. Warnert
The study is led by Robert Krieger, UC Cooperative Extension specialist in the Department of Entomology at UC Riverside. Krieger is an expert in environmental and occupational toxicology.
This summer, Krieger and a team of researchers spent nearly three weeks in Santa Maria with workers at DB Specialty Farms. The workers wear gloves as they pick strawberries. Before each break, their gloves are collected and frozen for later lab analysis.
“We’ve found that pesticides are transferred to the gloves during normal work and we’re measuring the amounts that are transferred in hopes that we can use it to measure total exposure,” Krieger said. “The real question is how much exposure occurs, how much is OK, and how little occurs under normal conditions of use.”
The team is also collecting samples of strawberries harvested by the workers and samples of leaves.
In order to understand uptake and excretion, the workers are asked to collect urine for 24-hour periods after working in sprayed fields. To be certain any sign of pesticides in the urine came from work exposure, the researchers have also collected 24-hour urine samples from spouses or roommates of the field workers to assess dietary or home exposure.
“The levels of exposure are determined by how much is applied, how much remains on the crop and how much is transferred to people. We’ve independently measured those and came up with an assessment of how much a person is exposed to during their normal work,” Krieger said.
The research focuses on two pesticides: the organophosphate malathion and the pyrethroid fenpropathrin. After the pesticides are applied, there is a three-day waiting period before harvest gets under way. In the project, as soon as the workers are back in the field, the monitoring begins.
Studies that Krieger has conducted over the past 18 years show that low, safe levels of pesticide are absorbed and rapidly excreted by harvesters. Breakdown products of the pesticides – parts of the pesticide molecule that are not toxic – can be measured in the urine, but it is not known whether the pesticide broke down on the plant, before the workers were exposed, or if the workers’ metabolism broke down the pesticides.
“Those breakdown products are not toxic, but if they are absorbed, they will appear in the urine and we can’t tell whether a plant made it or a person made it and that complicates our analysis and that’s one of the new areas that we’re investigating in 2012,” Krieger said.
By comparing the gloves, fruit, leaves and urine and using sophisticated metabolic chemistry in the laboratory analyses, the researchers will be able to reconstruct how much exposure there was during the work day.
If the research concludes that analyzing gloves is a useful way to measure worker exposure, gloves could become an important tool for farmers and regulators. Another probable area of impact from the study is in verifying the levels of exposure, which the researchers are finding to be very low.
“These workers have very low levels of pesticide exposure. And in fact, they’re the best-studied workers with respect to pesticide exposure in agriculture,” Krieger said. “That gives us confidence that the exposure is not having a health impact.”
Definitive results from the August study are expected in about six months.
The research program has been sponsored by strawberry growers of the California Strawberry Commission and the Personal Chemical Exposure Program, UC Riverside. The current Santa Maria research is possible by the involvement of DB Specialty Farms and Safari Farms of Santa Maria, and PrimusLabs.
The research was approved by the Institutional Review Board of UC Riverside and the California Environmental Protection Agency. All the participation is voluntary and the farmworkers and their spouses or roommates are compensated for the inconvenience of urine collection. They receive $25 for each 24-hour collection and a $100 bonus for completing all 10 urine collections.
In addition to the extra pay, the study volunteers benefit by helping improve pesticide safety for themselves and their colleagues.
“These workers are doing a service to other workers by allowing us to measure the amount of exposure that occurs during normal work,” Krieger said.
View video of the on-farm research below: