2002-2004 Specialty Crops Research Program
University of California

Principal Investigators: Mark Gaskell, Ben Faber, Ramiro Lobo, Elizabeth Micham

Project title: Development of Off-Season Fresh Market Blueberries as a
New Crop for Coastal California

We propose to establish field trials and laboratory postharvest studies to evaluate the factors limiting successful production of off-season fresh market blueberries in mild coastal California growing areas in San Diego, Ventura, and San Luis Obispo counties.

Preliminary field trials with blueberries growing in mild climate zones of California have demonstrated the potential for harvesting blueberries during early and late season market windows when blueberry prices are high. Results from these trials have led to the expansion of new blueberry plantings by California growers seeking alternative profitable crops (Faber , 2001; Gaskell, 2001a; M. Jimenez, personal communication), but there is little research-based information to guide new California blueberry growers. Estimates indicate between 400 and 1000 newly planted acres, with new plantings continuing. Blueberries require intensive management, are suitable for small-scale production, and are attractive to growing numbers of small-scale farmers in California.

Limited data is available from early field trials, but the most important information needed to guide commercial growers is not available. Information is needed on appropriate cultivars for the different growing areas, the optimum planting density for best production, and the potential for using covered tunnel production for earlier harvest, as is currently practiced for raspberries and blackberries in Southern California for off-season production. There is also a need to determine the production patterns for the different cultivars in the different growing areas to guide growers in targeting profitable markets.

There is no information on the postharvest performance of blueberries grown in California, and cultivar, climatic conditions, and cultural practices can have a large influence on fruit quality and storage life and, thus, marketability of the crop. The ability to extend the storage life of the fruit using modified atmosphere packaging with high carbon dioxide atmospheres, could be very profitable in extending the late market window. Also, the sensory quality of fruit can vary considerably by cultivar and production area, thereby influencing consumer acceptance.

There is an established market for blueberries in the U.S., so there is potential for expanding production without threat of over supply during early or late season production periods. As an example, the volume of blueberries in the US market in July is typically 20 to 40-fold the volume in March or April (Market News Branch, USDA-AMS, 2001).

Production, postharvest management, and marketing of blueberries is similar to other small fruits so blueberries are a new crop which complements the established small fruit industry of Southern and Coastal California.

This project proposes to establish three types of field trials in three growing areas (San Diego, Ventura, and San Luis Obispo Counties) with potential for off-season blueberry production. These trials will evaluate these critical aspects of blueberry production:
• Most suitable cultivars for the best productivity, fruit quality, and postharvest performance,
• Optimum planting density for intensive production,
• Production cycles of fresh market blueberries under covered field
tunnels compared to open-field culture.

The results from these field and storage trials, and related market price summaries will be presented to growers in a series of grower meetings featuring blueberries.