Cooperative Extension San Joaquin County
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Cooperative Extension San Joaquin County

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“Smart” orchard sprayers reduce pesticide use, protect waterways

Technology that allows orchard sprayers to skip the space between trees can protect the environment while saving growers money.

The idea is simple: when orchards receive dormant and in-season sprays of agricultural chemicals, the spray should only fall on the trees where it is needed, rather than on the ground, where it is not.

Orchard sprayers can be retrofit with target sensors that activate spray nozzles only when a tree is present.

A target-sensing smart sprayer travels between the rows of a Modesto almond orchard.
A review of research on this “smart” sprayer technology, published in the April-June 2011 issue of the University of California’s California Agriculture journal, found that the financial and environmental benefits of the technology are substantial.

“By reducing the application rate of the pesticide mix, each tank load of material covers a greater land area, effectively reducing the number or refills, ferry trips and time spent spraying each orchard,” wrote author Durham Giles, UC Davis professor of biological and agricultural engineering, in California Agriculture. “This provides additional economic return to growers by reducing labor and fuel costs.”

Based on field tests, the authors estimated that reductions in pesticide and operating costs with smart-sprayer technology ranged from $58 per acre for peaches grown in the San Joaquin Valley to $31 per acre for prunes grown in the Sacramento Valley.

At the same time, reductions in the total amounts of pesticide sprayed ranged from 15 percent for a mature prune orchard near Chico, to 22 percent for a mature almond orchard near Modesto, to 40 percent for a younger (more open) prune orchard near Oroville.

The trees themselves received the same amount of pesticide in the smart-sprayed orchards, but a lot less pesticide ended up on the ground than in the control. “For the almond and more open prune orchards, the reductions were 79 percent and 59 percent, respectively,” Giles and colleagues wrote.

Likewise, when the amount of pesticide in water running off from the younger prune orchard was measured, the reduction was 54% in the smart-sprayed orchard compared to the control.

Despite its obvious benefits, the study authors noted that “use of the smart-spray technology is growing but remains a small part of the spraying equipment market.” The retrofit spray sensor and control equipment cost about $15,000, with an estimated payback period of 2 years or less, given documented cost reductions.

Furthermore, the U.S. Department of Agriculture’s Environmental Quality Incentives Program (EQIP) can provide up to $30 per acre for a total of $15,000 per contract when the new equipment provides a 20% reduction in spray, which as been documented in peer-reviewed research such as the California Agriculture article.

“The amount is sufficient to adequately cover the cost of purchasing a typical target-sensing system for an orchard sprayer,” the authors note in California Agriculture journal.

Posted on Wednesday, April 20, 2011 at 8:31 AM
  • Author: Janet Byron

Keeping child care centers safe with integrated pest management techniques

With the early childhood eating habits of toddlers and young children, it is no surprise that preschools and child care centers often have problems with ants and cockroaches. Schools for the state’s youngest residents may also have concerns about black widow spiders, yellow jackets, mosquitos, rodents and other pests.

Many of the centers respond to the problem with pesticide sprays and foggers that could expose children and staff to residues on surfaces and in the air, a 2010 survey by the California Department of Pesticide Regulation revealed.

California’s Healthy Schools Act requires DPR to collect information about pesticide use and pest management in child care centers. The 2010 survey found that 55 percent of child care facilities use pesticides and 47 percent use foggers. One in five of the centers scheduled pesticide applications on a weekly or monthly basis, a strategy that is not recommended because applications may take place even when no pests are present.

The Healthy Schools Act also requires DPR to develop programs that encourage the facilities to voluntarily adopt integrated pest management practices, which emphasize pest monitoring, exclusion and safe treatment.

To help meet this requirement, DPR funded a Pest Management Alliance - including UC San Francisco’s School of Nursing, UC Berkeley’s Center for Children’s Environmental Research and the UC Statewide Integrated Pest Management Program - to develop a comprehensive pest management curriculum and outreach materials. The information is designed to help the centers minimize the risk of pesticide exposure and increase their use of safer pest management alternatives. This team created a detailed checklist that preschool directors can use to identify pest problems and find safe solutions, a 39-page curriculum, and four laminated posters:

  • Steps to a pest-free indoor environment
  • Steps to a pest-free outdoor environment
  • How to choose a safer pesticide to manage pests, with pictures of the best products to use and those that should be avoided
  • Clearly illustrated instructions for reading a pesticide label

The curriculum, which is available in English and Spanish, also includes 10 “health and safety” notes that detail pest problems and IPM strategies specific to common pests, plus a health and safety note that explains “green cleaning.”

The IPM strategy for ants, which pose the most common childcare center pest problem, begins with, “Don’t spray!”

“Spraying pesticides may kill ants, but spraying will expose staff and children to harmful chemicals and doesn’t eliminate ants in their nests,” the document says. “Pesticide residues can build up indoors where children spend a lot of time.”

Instead, users are advised to keep ants out by caulking cracks around foundations, removing plants and mulch that are within 12 inches of building foundations and removing ants’ food, water and shelter opportunities inside the facility. If other action must be taken to control the pest, IPM suggests the use of baits, not sprays, and as a last resort, hiring a pest management professional.

The curriculum can be downloaded for free from UCSF’s California Childcare Health Program website,

IPM techniques make child care centers a safer place for children.
IPM techniques make child care centers a safer place for children.

Posted on Wednesday, April 13, 2011 at 8:08 AM

Better living through green chemistry

We’ve all noticed the changed landscape on the grocery shelves: eco-friendly brands like Mrs. Meyers, Seventh Generation and even Clorox’s Sierra Club-endorsed Green Works sit next to conventional stalwarts like Tide, Cheer and those ferocious scrubbing bubbles. The new products are the consumers'-eye-view into a quiet “green chemistry” revolution taking shape in university and commercial labs across the country, and in education and public policy.

Even if the proliferation of green cleaning products, office supplies, packaging and appliances make the planet and its inhabitants healthier, the fact remains that more than 80,000 chemicals with uncertain health and environmental impacts currently are registered with the Environmental Protection Agency, with more discovered every day.

“Green chemistry involves discovering and implementing chemical processes and products that are safer, cleaner and more efficient,” said John Arnold, professor of chemistry at the University of California, Berkeley, and director of the campus’s Berkeley Center for Green Chemistry (BCGC).

Last month, the center hosted the sold-out event Green Chemistry: Collaborative Approaches and New Solutions,” the first national conference to take a multidisciplinary approach to this developing area of study. Speakers and panelists came from the EPA, California state government, private industry, departments across the Berkeley campus, and universities across the country, including the 2005 Nobel laureate Robert Grubbs of Cal Tech.

“The Berkeley Center for Green Chemistry has created a multidisciplinary team that represents all aspects of chemistry, from research and development to consumers and the environment,” Arnold said. “Through research, education and engagement, we aim to facilitate change by embedding the principles of green chemistry into science, markets and public policy.”

The BCGC already has begun redesigning undergraduate and graduate student education to include green chemistry by creating greener laboratory experiments and launching an interdisciplinary graduate course in green chemistry funded by California Environmental Protection Agency. But the center aims for a broader impact – on public policy as well as on the chemical industry. “We’re trying to promote activities that address more than one aspect of green chemistry, that also look at economics, business, law, toxicology or public health,” Arnold said.

Green chemistry programs are not new at universities or in the research labs of chemical companies, but most focus only on innovations in chemistry, such as developing catalysts or safer solvents, according to Alastair Iles, a UC Berkeley assistant professor of environmental science, policy and management and a center member. Iles said that these technical developments are critical to achieving sustainability, but they won’t be as effective or be widely used without also finding societal innovations in policy, law, environmental health and business.

“In contrast, BCGC has a vision of integrating multiple disciplinary fields with chemistry so that chemists can work with toxicologists, business experts, regulators and economic experts to develop technologies and products that are non-toxic and sustaining,” Iles said.

Center executive director Marty Mulvihill said that green chemistry is already being taken up by industry because it’s cheaper, it doesn't produce as much waste, it uses less energy, and it creates products that are safer, without the worry over what's going to happen at the end of a product's life.

“It just needs to be taken up by the entire industry in a transparent way that gives businesses and consumers the information they need to make choices,” said Mulvihill.

A key 2008 study led by UC Berkeley environmental health scientists and their UCLA colleagues, formed the technical basis for the state’s Green Chemistry Initiative and new legislation authored by Senator Joe Simitian (D-Palo Alto) and Assemblymember Mike Feuer (D-Los Angeles). Those new laws, and their implementing regulations, could improve public access to information on the sale of chemical products in the state and reductions in some uses of the most toxic chemicals, according to Michael Wilson, BCGC associate director for integrative sciences and an environmental health scientist at UC Berkeley's Center for Occupational and Environmental Health.

As members of the state’s Green Ribbon Science Panel, Wilson and his co-author Megan Schwarzman, the center’s associate director of health and environment, have worked with the DTSC to shape the Green Chemistry Initiative, with the hope that it will improve transparency and accountability in the chemicals market.

“Ultimately, in society, what we would like to see is the design of chemicals and products that don’t come at the expense of humans or the environment,” said Schwarzman. “That would mean creating chemicals that are short-lived and degrade in the environment so they don’t show up in breast milk 30 years after they have been banned, and industrial processes that use benign substances. I think we have the ingenuity and the know-how to do that, and we have to prioritize it as a society.”

Posted on Wednesday, April 6, 2011 at 7:28 AM
  • Author: Ann Brody Guy

Agricultural water conservation — a serious look

With this latest set of storms replenishing California’s snowpack and water levels in reservoirs, rivers and streams, it may be hard to think about water conservation issues. But this is a still a semi-arid state, so it is always prudent to prepare for droughts.

So where can we save the most water? Farming in California depends on irrigation, so agriculture seems the largest potential source for cost-effective water savings in the state. Although agriculture’s share has been declining, it still accounts for roughly 75 percent of all human water use, compared to 25 percent for urban uses.

The recent book, Managing California’s Water: From Conflict to Reconciliation, examines agricultural water conservation extensively and points out the complexity of this issue.  The book’s findings are based on scientific and economic research and field experience in California and worldwide.

Much agricultural water is still devoted to relatively low-value crops:  In 2005, over 60 percent of “net” water use in the agricultural sector – the amount consumed by crops – was for irrigation of pasture and field crops such as alfalfa, corn, rice, and cotton, which generated only 14 percent of crop revenues. These statistics imply significant potential for reducing farm water use without incurring overwhelming consequences for the state’s economy.

Contrary to popular understanding, however, improving on-farm irrigation efficiency is usually a poor way to achieve real agricultural water savings.  Real conservation usually requires shifting to crops that use less water or reducing crop production, such as by fallowing farmland. This is because much of the irrigation water applied when farmers use “inefficient” techniques like furrow irrigation is returned to streams or aquifers, where it becomes available for reuse.

This is the international scientific consensus on irrigation conservation, from studies worldwide. Most groundwater recharge in California’s Central Valley is from irrigation runoff and percolation. This recharge helps to replenish depleted aquifers and serves as a significant source of supply during drought. Only a few areas in California, such as the Imperial Valley, can save large amounts of water by adopting more efficient irrigation techniques. In such areas, the excess irrigation water flows into saline water bodies or contaminated aquifers, where it is unavailable for reuse, so reducing runoff generates real water savings.

Even though improving irrigation efficiency usually does not produce significant real water savings, it can provide economic benefits for farmers.  Farmers usually pay for the amount of water they apply to their fields, not the amount consumed by crops.  When farmers face limited supplies, they often have an incentive to adopt more efficient techniques, such as drip irrigation, to make use of every possible drop on their farms.

These techniques, often combined with laser leveling of fields and more precise doses of fertilizers and pesticides, can improve crop productivity and quality. In recent decades, many San Joaquin Valley farmers have made such changes, which have enabled them to plant greater acreages of higher-value fruit, nut and vegetable crops.

Improving irrigation efficiency also can provide environmental benefits. For instance, agricultural runoff sometimes contains harmful salts and other chemicals, and more efficient irrigation can help reduce these discharges.  This is another reason for the rise in more efficient irrigation techniques on the west side of the San Joaquin Valley, where farmers are required to limit runoff of selenium, a toxin to wildlife. Similarly, by reducing diversions, irrigation efficiency may allow higher streamflows on particular stretches of rivers, improving conditions for aquatic life.

Although counterintuitive, more efficient irrigation techniques also can increase water consumption. By allowing farmers to farm their fields more intensively and to expand irrigated acreage with the water they “save,” techniques like drip irrigation can increase net farm water use within a region, thereby reducing groundwater recharge and nearby streamflow.  Conservation-oriented policies that neglect this possibility can exacerbate groundwater overdraft, as studies from New Mexico to Yemen have shown.

What is the right policy to encourage effective agricultural water conservation? It depends on the objective. To encourage real water savings, the best policy is to let market forces work. Water markets are a flexible and efficient way to encourage farmers to create real water savings for higher-valued uses. California needs to improve the ability to buy and sell water, by reducing state and local barriers, to give farmers better price signals. To reduce polluted agricultural runoff or improve streamflows in some areas, the best policy is to adopt regulations that directly address pollution discharges and instream flows, and allow farmers to choose the most cost-effective way to meet these requirements.

In contrast, policies that impose particular irrigation technologies, or even ban specific crops, are likely to impose higher costs on farmers and society, while failing to save real water. Given the immense variety and variability of conditions in California, rigid regulatory policies to promote agricultural water conservation seem more likely to create more controversy and increased social cost than usable water savings.

Agricultural water conservation is an important part of California’s water future. But simplistic notions of water conservation threaten to mislead California’s water policy debates by presenting the false claim that water saved from on-farm use is necessarily water saved to the system. It is time to take water conservation seriously. In doing so, we also must undertake water conservation scientifically, rather than rhetorically.

(This post is excerpted from the California WaterBlog—“Taking Agricultural Conservation Seriously”.)

Posted on Wednesday, March 30, 2011 at 8:41 AM
  • Posted By: Trina Wood
  • Written by: Jay Lund, Ellen Hanak, Richard Howitt, Ariel Dinar, Brian Gray, Jeffrey Mount, Peter Moyle, Barton “Buzz” Thompson

UC offers webinar series on community forests

If you are passionate about a forest near you then you may want to tune into the UC Cooperative Extension webinar series on Community Forests.  The webinars will begin at 6:30 p.m. Pacific Standard Time on April 7 with additional programs on April 13, 20 and 27. Participants may also want to take part in related field trips to Arcata Community Forest, Usal Redwood Forest, Tahoe-Donner and Weaverville Community Forest.

Community forests are forested lands that are managed to produce what people value. Forests may be valued as a source of timber for lumber, clean water, wildlife habitat, recreational purposes or for all of these benefits in combination.

The webinar series aims to present an overview of community forestry as it is currently being practiced in California. The intended audience is natural resource managers, environmental and forest activist groups, residents of forested regions who might benefit from a community forest approach in their areas and the general public concerned with forest management.

This program is a collaborative effort of the University of California Cooperative Extension and the Northern California Society of American Foresters, with funding support from the USDA Forest Service and the University of California.

Additional information and a link to registration are available at

UC collaborators on the project are natural resources advisors Mike De Lasaux, Susie Kocher, Gary Nakamura and contractor Richard Harris.

A webinar series and field trips will educate the public on community forests.
A webinar series and field trips will educate the public on community forests.

Posted on Thursday, March 24, 2011 at 8:26 AM
Tags: forest (12), Gary Nakamura (1), Mike De Lasaux (4), Susie Kocher (14)

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