Organic Apple Production in California: On-farm Research and Extension Partnership Produces First
Regional Production Guidelines

Sean L. Swezey

In 1992, a USDA Western Region SARE grant for a project entitled "Comparative Performance and Farm-Level Function of Organic Apple Production Systems in California" was made to an interdisciplinary team of four University of California specialists and farm advisors: Sean Swezey, Paul Vossen, Janet Caprile and Walt Bentley – each with research and extension duties in major California apple production areas. The objectives of this project were to: 1) establish, with cooperating growers in each production region, comparative on-farm demonstration blocks of organic and conventional apple production; 2) compare yield and economic performance; 3) monitor leaf nutrients, soil characteristics, and key pest incidence, damage and natural enemy abundance; 4) determine the effectiveness of key management innovations important to organic apple production (including codling moth mating disruption, cover cropping and compost application, and sprayable inorganic compounds as organically-acceptable disease control agents); and 5) disseminate research results to the production community, culminating in the publication of the "Organic Apple Production Manual," the first such University of California production system manual.

Three large-scale, multi-year regional comparison sites and seventeen additional component research sites were established statewide. Eleven growers assisted the project in design, procedures, management, and evaluation of results, and an additional group of twelve growers contributed test ground and management skills in specific orchards. On-farm research collaborations at these sites greatly improved our understanding of the mix of key production practices changes important for successful organic apple production in California.

Our research collaboration with growers demonstrated materials and methods effective for organic apple production. Pheromone-based mating disruption, either alone or in combination with other biological and cultural controls, is a successful codling moth management method for California organic growers, especially in low to moderate pressure sites isolated from nearby sources of uncontrolled moth infestation, in cooler coastal climates, and on early harvest varieties. Organic growers should not abandon normal sanitation and other cultural practices for this key pest, and high pressure situations require supplemental controls. Consistent, up-to-date codling moth monitoring methods are critical to the success of codling moth mating disruption in organic orchards. Testing in six on-farm experiments also showed that properly timed sulfur sprays and/or fixed copper materials perform as well as synthetic fungicides for scab control and do not cause excessive phytotoxicity or fruit russeting under appropriate use conditions. Multi-year observations also indicate that it is not difficult to provide adequate nutrients to apple trees under organic management with a cover crop and compost application based program, including supplemental, organically acceptable mineral applications if necessary.

Cost of production studies indicated that farmgate costs for California organic fresh market apple production ranged from $3,300-4,100/acre in the coastal production zones, and in general, labor and materials costs exceeded conventional costs by 10-25%. This cost of production differential was lower in the Northern San Joaquin Valley. When organic premiums were available and yields ranged from 10-20 tons per acre (depending on variety) net returns ranged from $2-6,000/acre for fresh market organic apples. Total accumulated three-year returns for Northern San Joaquin Valley organic Granny Smiths were equivalent to conventional returns, and Central Coast organic Granny Smith production consistently out-earned conventional production over three years.

Our research team published our results in 1994 in a special issue of the University of California’s peer-reviewed journal, California Agriculture, organized and presented our findings to apple growers in eight grower meetings from 1993-1996, and in 1998 at the first University Extension-sponsored short course on organic production for a California commodity ("Organic Apple Production Short Course" in Santa Rosa). We invited ten additional farm advisors and specialist colleagues to co-author University of California, Division of Agriculture and Natural Resources Publication 3403, "Organic Apple Production Manual," the first such production manual for an organically-produced commodity in the state. The farmer-researcher partnership, which included multi-year, on-farm, region-specific research and demonstration, cost of production studies, local field days, a statewide short course, and a published production manual, represents a support model for a growing production practice representing over 4,000 state-registered acres, approximately 10% of the statewide total. The combined value of organic apple production and product processing and handling in California has grown rapidly, to over $14 million in 1998 according to information compiled by the California Organic Program of the California Department of Food and Agriculture.

Sean L. Swezey
Director, Sustainable Agriculture Research and Education Program
Center for Agroecology
University of California
Santa Cruz, CA 95064
Tel: (530) 752-2379
findit@cats.ucsc.edu

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