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Open Access Publications from the University of California

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California Agriculture is a quarterly peer-reviewed journal reporting research, reviews and news on California’s agricultural, natural and human resources.

Volume 58, Issue 4, 2004

Issue cover

Articles

Racing for crabs . . . Costs and management options evaluated in Dungeness crab fishery

Dungeness crab support a valuable commercial fishery in California, yet in recent decades the fishery has intensified significantly, with most crab landed during the first 6 weeks of the 7-month season. This study of fishermen’s operating costs and their opinions of new management measures is intended to support discussions and decision-making about policy changes that may affect the economics of the fishery. Our survey results show that a majority of fishermen have favorable views of only two of 12 alternative measures (one trap-limit for all size vessels and daylight-only fishing). However, opinions of these measures vary between owners of different-sized vessels. Experiences in other crustacean trap fisheries around the world suggest that simply implementing these two measures may not significantly decrease total trap numbers fished or slow the race for crab.

Conserving California fish . . . Extension approaches applied to contentious marine-fisheries management issues

We describe three creative collaborations between the California Sea Grant Extension Program (SGEP), the California Department of Fish and Game, the fishing industry and university researchers to improve marine fisheries management in California. These collaborations involved difficult and long-standing issues at a time when many fisheries are declining. The cases studied highlight SGEP’s involvement in (1) implementing California’s comprehensive marine-life management legislation, (2) helping the sea urchin industry identify goals and techniques to achieve them, and (3) using extension methodologies to enhance socioeconomic research related to management of the Dungeness crab fishery. Critical components of SGEP methods were trust, independence and nonadvocacy, a science-based approach, and effective communication. These characteristics are seldom found together among diverse participants involved in contentious fisheries-management situations. We demonstrate how extension programs can partner with constituents and agencies to improve the management and research process; this approach can be applied to the broad range of natural-resource issues facing the state.

Davis school program supports life-long healthy eating habits in children

The school environment can positively affect students in areas beyond traditional academic achievement. An innovative program in Davis, the Farm to School Connection, sought to promote the development of life-long healthy eating habits in children and to create a school environment that made connections among the school garden, cafeteria and classroom, and linked them to local agriculture. This comprehensive program included farmers’ market salad bars, classroom education, farm tours and waste management. We evaluated the effectiveness of the program via interviews and surveys of program leaders, teachers and school staff. Participation in the school lunch program increased with the addition of the salad bars, and numerous partnerships developed among those involved. Components of the Farm to School Connection provide evidence to support comprehensive school nutrition programs and the positive impact they can have on the school environment.

Diet, shopping and food-safety skills of food stamp clients improve with nutrition education

The California Food Stamp Nutrition Education Program (FSNEP) reaches approximately 50,000 families with children and individuals annually. Results from the 2001-2002 fiscal year demonstrated improvements in a variety of dietary and food-safety skills after clients received FSNEP training. In addition, results from a subsample (n = 460) showed significant improvements in the amount of money saved on food purchases, along with improved dietary quality. FSNEP provides food stamp clients with needed nutrition skills and promotes behavioral change to help them stretch limited resources. Program management practices have had positive effects on the program’s overall operation and growth.

Animal Ambassadors . . . 4-H teens learn to lead science program for kids

To improve science literacy among school-age children in the United States, educators must receive effective training and support, and children must be engaged in science at a young age. Animal Ambassadors is a science-education outreach program of the UC School of Veterinary Medicine, Veterinary Medicine Extension, which focuses on the awareness and understanding of animal-related concepts and emphasizes important critical thinking and life skills. Through a collaboration with UC Cooperative Extension’s San Luis Obispo County Youth Development Program, an Animal Ambassadors research project showed positive outcomes relative to interrelated goals involving teen training and youth science literacy.

Low-toxicity baits control ants in citrus orchards and grape vineyards

Effective ant control is critical for controlling honeydew-secreting homopteran agricultural pests such as whitefly and mealybug. Low-toxicity ant baits may more effectively control ants than the broad-spectrum insecticides currently used in California vineyards and citrus orchards. This study focused on developing effective ant baits for use in bait stations to control field ant and Argentine ant, which aggressively tend homopteran pests. In the Coachella Valley, field ant is associated with the vine mealybug, a destructive nonnative pest. We conducted preference experiments for various commercially available ant baits and a bait formulated with anchovy plus imidacloprid. Field ant preferred the anchovy baits above all others tested, and in field trials the anchovy bait with 0.005% imidacloprid significantly reduced foraging activity. Argentine ant is the primary ant pest in vineyards and citrus orchards of California’s nondesert growing regions. We tested the efficacy of several chemical bait treatments, all of which significantly lowered Argentine ant populations.

Weeds accurately mapped using DGPS and ground-based vision identification

We describe a method for locating and identifying weeds, using cotton as the example crop. The system used a digital video camera for capturing images along the crop seedline while simultaneously capturing data from a global positioning system (GPS) receiver. Image time-stamps were synchronized with GPS time so that GPS coordinates could be overlaid onto selected images. The video system continuously mapped nutsedge weeds and crop plants within the seedline, allowing weed locations to be described with centimeter-scale accuracy when using a real-time kinematic GPS (RTK-GPS). This system may be used to develop maps of weed and crop populations as part of precision crop-management decisions.