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Open Access Publications from the University of California

Volume 64, Issue 1, 2010

Volume 64 Issue 1 2010

Issue cover

Research and Review Articles

New Zealand lessons may aid efforts to control light brown apple moth in California

New Zealand’s major fruit industries are dependent upon producing high-quality crops for export with a very low incidence of pest damage. Light brown apple moth was an economically important pest within the fruit sector in the 1960s through the 1980s, and it developed resistance to broad-spectrum insecticides. The increase in its pest status focused research on biological control, and existing native natural enemies were augmented with new introductions from Australia in the late 1960s. By the early 1990s, this effort resulted in substantially reduced leafroller populations and fruit damage. The implementation of integrated pest management (IPM) programs in the New Zealand fruit sector in the mid- to late 1990s practically eliminated the use of broad-spectrum organophosphate insecticides, further enhancing natural control. Today light brown apple moth is successfully managed in IPM and organic programs through a combination of biological control and threshold-based applications of selective insecticides.

Airborne particles in the San Joaquin Valley may affect human health

Air quality is a primary concern for many San Joaquin Valley residents. In addition to rapid population growth, a widening interface between urban and agricultural communities, and increasing traffic along the I-5 and Hwy. 99 corridors, farming practices in the San Joaquin Valley subject agricultural workers to high concentrations of airborne particulate matter potentially associated with adverse health effects. We created a research team and mobile field unit equipped with a special inhalation system, particle monitoring and characterization abilities, and housing for the transport and care of animals to examine the effects of particulate matter throughout the San Joaquin Valley. With this system, a variety of biological endpoints can be examined to determine respiratory, systemic and neurological responses to short-term particle exposure. Field research of this nature coupled with biological assays and location-specific inhalation studies can help researchers and regulators to better understand potential health effects due to environmental and occupational airborne-particle exposures faced by workers and residents in the San Joaquin Valley.

Research and outreach can lessen the overall burden of diabetes in farmworkers

Type 2 diabetes is increasing rapidly in the United States and Latin America and contributes significantly to the rise in health care spending. Diabetes increases the risk of cardiovascular disease, renal failure and blindness, and leads to other complications. Type 2 diabetes and its complications can be delayed in high-risk individuals through a healthy lifestyle and ongoing medical care. Some research suggests a relationship between diabetes and other underlying metabolic conditions, either as predisposing factors or as adverse outcomes of occupational exposures in farmworkers. UC Cooperative Extension can have a greater impact on the health and safety of California’s workforce by filling in research gaps and strengthening collaborations.

High risk of depression among low-income women raises awareness about treatment options

Depression in young women living in poverty has devastating consequences if left untreated. Low-income women are at a higher risk for depression than other income groups, and the majority of these women are untreated. The Center for Epidemiologic Studies Depression Scale was used to assess depression symptoms in women under 45 years old in five California counties. More than 45% were identified as depressed, and the highest level of depressive symptoms was found in Sonoma County. We also found a significant negative association between the number of people in the household and depressive symptom scores, that is, with fewer people in the household depression increased. This result may indicate the need for a support system that is more accessible to individuals in smaller households or it may be an artifact of Hispanics having larger families and lower depression scores. Our results indicate that there is a critical need to provide mental health resources to low-income women, especially those with young children.

Nurseries surveyed in Southern California adopt best practices for water quality

A variety of good management practices have been recommended to minimize the impact of water runoff from production nurseries. However, studies have not been conducted to gauge which management practices nursery producers are most likely to adopt in response to education and increased government oversight. We surveyed 85 production nurseries in Southern California about their existing practices to limit the impacts of runoff from their facilities. Of these, 65 in Ventura County were resurveyed with the same questionnaire within 2 years. The positive response rate for following good management practices was 65%, compared to 57% in the initial survey. There were significant increases in every category of practices surveyed, and significant changes in the adoption of 38 specific practices. This suggests that nurseries are amenable to adopting management practices within a short time span in areas where there is increased governmental oversight and educational opportunities for growers.

Pruning reduces blister rust in sugar pine with minimal effects on tree growth

Sugar pine trees from nine stands in two California study areas were assessed to determine the effects of pruning on the incidence and growth of white pine blister rust. Lower limbs up to 8 feet high were removed on alternate trees. Six years following treatment, the number of infections in pruned trees was reduced compared to unpruned trees at one study area, but no blister rust was found at the other area. The results suggest that artificial pruning of sugar pine may be part of an effective, integrated strategy to maintain this species in mixed-conifer California forests.

Strawberry breeding improves genetic resistance to Verticillium wilt

Since 1994, more than 480 genotypes from the UC strawberry breeding program have been screened for resistance to Verticillium dahliae Kleb., an important soil pathogen of strawberry. Genotypes for parents of subsequent generations have been chosen using a multiple-trait strategy that incorporates their Verticillium resistance rating. This selection strategy has increased resistance scores for the parents by 60%, and increased the percentage of moderately resistant genotypes from 35.0% in the original germplasm to 78.5% in those used as parents for the most recent crosses. Selection has reduced genetic variation for the resistance score, and genotypic coefficients of variation (GCV) decreased in the breeding population from 34.4% to 11.6% from 1994 to 2008. Inspection of genotypic scores suggests that the GCV change pattern may not be due to a scarcity of variation, but rather to limitations in the detection test. Our results suggest the need for broader testing of the more-resistant types identified in naturally infested soils and improved understanding of resistance mechanisms. Ultimately, this work seeks to provide a Verticillium-resistant cultivar to growers if access to effective soil fumigants becomes more limited.

Wine-grape production trends reflect evolving consumer demand over 30 years

The California wine industry has been in the midst of a prolonged boom for more than 30 years. In 1975, California was home to approximately 330 wineries; by 2006 there were nearly 2,500. There has been a dramatic shift in demand toward higher priced and higher quality table wines, as reflected in the total revenues and crush shares of the state’s four major growing regions. We examine the major trends in the California wine-grape industry over the last 30 years, specifically differences that are arising between the coastal and inland growing regions and migration of the various wine-grape varieties grown throughout the state.


Light Brown Apple Moth - A Letter Report by the National Research Council

The presence of Light Brown Apple Moth (LBAM) has resulted in a federal order that restricts the interstate movement from affected counties of several regulated articles, including specific agriculture commodities as well as their byproducts. The United States Department of Agriculture’s Animal Plant Health and Inspection Services (USDA-APHIS) is responsible for taking actions that exclude, eradicate and/or control plant pests and has classified LBAM as an actionable quarantine-significant pest. To classify a pest as actionable, its presence must have potential significant economic importance. Early last year, APHIS responded to requests to reclassify LBAM as a non-actionable pest. The National Research Council reviewed the APHIS response in a report released September 2009 and found that APHIS was within its authority to classify LBAM as actionable; however, it suggested the agency re-focus on the question of why this pest is important to the US and to base their response on a detailed economic analysis and a clear justification of their choice of regulatory actions.