California ranks first in the U.S. in both the number of farms growing garlic and in harvested acres with over 21,472 acres harvested in 2017 compared to the U.S. total harvested acreage of 24,600.  More than 3,516,713 cwt. of garlic were produced in the state in 2017 with a value of nearly $220 million. California produced approximately 90% of all commercially grown garlic in the U.S. in 2017.  Approximately 40% of the California garlic crop is grown for processing/dehydration, while 60% is for fresh market. Garlic for seed is grown in Nevada, Oregon and Washington and represents over 2,000 acres. Although garlic is grown in several regions in California, nearly 92% of the total garlic grown in the state is in the western San Joaquin Valley counties of Fresno, Kings and Kern.

Integrated pest management (IPM) information is continuously being developed for weed, insect, nematode and disease problems of California garlic. The industry, through the California Garlic & Onion Research Advisory Board, provides more than $100,000 annually in research grants to address production problems, mostly concerning pest management issues.

California is ideally suited to growing high quality garlic. While the major production region is located in the western San Joaquin Valley, minor production regions include the southeast desert counties of Riverside and San Bernardino, northern California counties of Lassen, Siskiyou and Mono, and central coastal counties of San Benito and Santa Clara. Pest issues vary according to area of production, but in the major production areas in the San Joaquin Valley, the key problems in garlic production consist of diseases, weeds, insects and mites and, to a lesser extent, nematodes. These pests have in large part been controlled, or managed, by a program of crop rotation, sanitation, use of certified seed, fertility and irrigation management, avoidance (such as avoidance of known infested white rot fields) and use of pesticides. Organic garlic production in California is estimated to be about 5 to 8 % of the total acreage grown.

The California garlic industry faces significant challenges with the increasing spread of the white rot (Sclerotium sepovorum) organism throughout prime Westside farmland, increase in thrips resistance to pyrethroids, more weed control issues, increasing production costs, and a highly competitive global marketplace. In addition, the industry is concerned that new regulations set forth by both state and federal agencies may significantly impact the availability or use patterns of important crop protection chemicals and water used by growers. While this industry has recognized the need to evaluate, register, and implement reduced risk production practices, there are relatively few new products being evaluated. As the costs to conduct required research and register new materials increases, registrants are less willing to focus on commodities with relatively few acres (as compared to major crops such as corn, soybeans, etc.), simply because their return on investment is significantly lower. Therefore, many minor crop commodities, such as garlic, are more likely to lose pest management tools, with less likelihood they will be replaced by new products. Also, of great concern to the industry is the loss of University of California Cooperative Extension support for the industry and there is a need to replace current specialists and advisors who are retiring or moving on to other positions.

This Pest Management Strategic Plan for California Garlic includes a comprehensive summary of the crop production and pest management practices used by the garlic industry in California. The foundations for this document are the “Crop Profile for Garlic in California” (https://.ipmcenters.org/documents/cropprofiles/CAgarlic.pdf) and the “UC IPM Guidelines for Garlic” (http://ipm.ucanr.edu/).

Key Pests