The vegetable crops industry in San Joaquin County comprises 86,800 acres and has a farm-gate value of more than $241 million. Major crops include asparagus, processing tomatoes, fresh market tomatoes, potatoes, bell peppers, pumpkins, cucumbers, onions and mixed melons. We annually conduct between 30 and 40 research trials with local grower cooperators seeking to improve crop production and solve pest management (weeds, diseases, nematodes, insects) and plant nutrition problems affecting local vegetable producers. These collaborative research efforts are financially supported by four grower commodity boards (California Asparagus Commission, California Tomato Research Institute, California Tomato Commission, and the California Pepper Commission), and a number of chemical manufacturers and seed companies, which allows the local industry to remain one of the top vegetable production areas of the state.
Research highlights/impacts include the following:
Annual variety evaluation trials in processing tomatoes, fresh market tomatoes, potatoes, and bell peppers have resulted in almost a doubling of production over the past 20 years, and have allowed growers to remain profitably competitive, while still trying to offset foreign imports of many commodities.
Long term asparagus cultivar evaluation trials have included varieties not only from the University of California, but also from around the world. These trials seek to find the best production and quality characteristics for asparagus that will allow this county to remain the number one producing area in California and the nation, while maintaining its status as a major export crop to the Pacific Rim and Europe. Increased imports from Mexico and Chile are a major concern to California growers.
Weed management trials in tomatoes, where we have been one of the principal researchers, involved registering the first new preemergence/postemergence herbicide for tomatoes in nearly 30 years. This herbicide called Shadeout was registered in April 1998 and is saving local growers up to $250.00 per acre through reduced weeding costs and increased production or, based on acreage, $7.6 million savings per year. Also, Sandea, another herbicide for postemergence control of yellow nutsedge, is expected to be registered in spring 2003 due to our research effort. This could result in savings of another $5 million to local growers, plus reducing nutsedge problems and costs on following rotational crops.
Disease control trials in processing and fresh market tomatoes are making significant progress to control/suppress plant disease pathogens such as Fusarium Foot Rot, Blackmold, Late Blight, and Powdery Mildew. Collaborative efforts with other UC researchers and industry representatives are seeking to find both chemical and biological tools to control these plant diseases. We are also looking at weather monitoring crop models that could lead to disease forecast systems which better predict the onset of disease and reduce the number of pesticide applications.
Insect trial work is seeking to find effective control materials for Garden Symphylans in both tomatoes and asparagus with promising results thus far.
