Growers are most likely to trust their county's agricultural commissioner, Farm Bureau and UC Cooperative Extension office for information about water-quality management, according to a peer-reviewed study published in the July-September 2007 issue of the University of California's California Agriculture journal (http://californiaagriculture.ucop.edu).

Mark Lubell, UC Davis associate professor, and Allan Fulton, UC Cooperative Extension advisor, surveyed more than 1,200 growers in the Sacramento River Valley about how they make production decisions regarding water-quality management. The surveyed growers had the lowest levels of trust in the U.S. and California environmental protection agencies, and the state water board.

The survey also found that Sacramento River Valley orchard growers need an average of nine contacts with a "diffusion network" of peers, private advocacy groups and public agencies before they will adopt a new best management practice (BMP) to protect water quality. The authors define a diffusion network as a social system for communicating information about agricultural practices, through both formal and informal connections and interactions. BMPs include sustainable practices such as calibrating pesticide sprayers, providing habitat for beneficial insects, and planting filter strips to control runoff.

The research has important implications for policymakers and Central Valley growers as they grapple with water-quality regulations. In January 2003, the Central Valley Water Quality Control Board (Region 5) adopted the so-called "Conditional Waiver," which regulates water quality across a vast swath of California agricultural land. The Conditional Waiver is still contested today; one way that growers can comply is by joining a watershed management coalition, in this case a diffusion network called the Sacramento Valley Water Quality Coalition.

The survey found that "the more producers interacted with diffusion networks, the more likely they were to be satisfied with watershed management policies, participate in policy activities and adopt environmentally sound practices, as long as they were cost effective," Lubell and Fulton wrote.

Also: The July-September 2007 issue of California Agriculture journal includes four peer-reviewed articles on obesity, including a systematic analysis of dietary factors that influence obesity; new research on possible links between food insecurity and childhood obesity in low-income Mexican-American families; new research on an association between overweight and obesity, magnesium deficiency and asthma rates; and case studies of coalitions working to prevent obesity in California communities. Another peer-reviewed study compares the quality characteristics of late-season navel orange varieties.

California Agriculture is the University of California's peer-reviewed journal of research in agricultural, human and natural resources. For a free subscription, go to: http://californiaagriculture.ucop.edu, write to calag@ucop.edu or call (510) 642-2431 x33. For a hard copy of California Agriculture, media should e-mail janet.byron@ucop.edu or call (510) 642-2431 x19.