Annual Reports

2002—IPM in Action:

Water quality in California is a big issue for today’s nursery growers. Regulatory agencies are setting Total Maximum Daily Loads (TMDLs) for various pesticides to limit water quality impacts. As a result, commercial nurseries are taking a closer look at how they can reduce pesticide use as well as water runoff, which can carry potentially harmful materials.

Cheryl Wilen, UC IPM Advisor for ornamental crop production and maintenance in southern California, is conducting a demonstration project to show growers ways to reduce herbicide and irrigation runoff. As part of a Pest Management Alliance grant from the California Department of Pesticide Regulation, Cheryl is using plant containers originally developed for the interiorscape industry and adapting them for outdoor use. The pots have a "well" in their base and the plants are individually subirrigated.

Water runoff is minimized because each pot is irrigated by a single water emitter and the entire irrigation system is connected to a moisture sensor so that the crop is only watered when the potting mix reaches a set level of drying. She is also examining the use of this system in relation to weed control because a drier soil surface would not be a good substrate for blown-in weed seeds to establish.

Keeping an Eye on Grape Pests Along the North Coast

In recent years we have seen an increase in populations of the European fruit lecanium scale in North Coast wine grapes. Although historically a common pest in prunes in the region, the advent of damaging populations in grapes is new. Lucia Varela, North Coast UC IPM Advisor, is studying the biology of this scale on grapes, and has found that, contrary to previous research findings, there is more than one generation per year in the North Coast.

This has implications for the timing of control measures and the effectiveness of natural enemies. She is investigating the timing of reduced-risk insecticides and, in collaboration with Extension Entomologist Kent Daane, is collecting the natural enemies attacking this scale.

Grape whitefly is seen as a pest on grapes grown near chaparral vegetation, where it overwinters in coffee berry. In spring, whitefly adults move to the adjacent grapes where they lay eggs. Once hatched, large numbers of nymphs produce honeydew providing a substrate for a black sooty mold growth, which affects the quality of grape bunches. A complex of parasitoids composed of primary and hyperparasites (a parasite attacking a primary parasite) are associated with this whitefly. Studies are being conducted to determine when whitefly outbreaks might occur and to develop control strategies.

Lucia continues to work on extending information on glassy-winged sharpshooter and Pierce’s disease. She co-authored the publication Pierce’s Disease with Viticulture Advisor Rhonda Smith and UC IPM Advisor Phil Phillips and produced a video titled "Glassy-winged Sharpshooter Identification and Monitoring," available in English and Spanish.

High Temperature Solarization Kills Weeds and Nematodes For warm-climate nursery producers and home gardeners wanting to disinfest soil for weed-free container growing, a "double-tent" solarization technique can be a useful, low-cost alternative. Kearney Agricultural Center-based UC IPM Advisor and Plant Pathologist Jim Stapleton, heading a group including graduate students Susan Mallek and Tarcisio Ruiz, former IPM Weed Ecologist Tim Prather (now at University of Idaho), and UC Davis Weed Specialist Clyde Elmore, have been developing a solarization technique for pest control in containers. This technique has been approved by the California Department of Food and Agriculture for nematode-free container nursery production and will also eliminate seed viability of important weeds including common purslane, tumble pigweed, and black nightshade. Using a threshold soil temperature of 140°F, all seeds failed to germinate after 1 to 2 hours of solar heating in moistened soil. Soil in smaller-volume containers reached higher temperatures and maintained them longer than soil in larger containers. Results of the technique have been extended to growers and container nurseries, and will be formally published in the October/December issue of the journal HortTechnology. This research was originally sponsored by a UC IPM Research Grant.

IPM in Vegetable Crops: Eggplant and Lygus Bug

Eggplant is a specialty vegetable crop grown primarily in the southern desert valleys, San Joaquin Valley, and southern coast. In the year 2000, 1,700 acres of eggplant were harvested, valued at $14,362,000, with small-scale farmers in Tulare and Fresno counties producing the major portion of the crop.

Lygus can be a key insect pest, feeding on flower buds and causing the buds to drop, delaying fruiting, and reducing the yield potential. Since little is known about the relationship between eggplant and lygus, Pete Goodell, UC IPM Advisor and IPM Entomologist, together with Tulare County Farm Advisor Manual Jimenez and Fresno County Farm Advisor Richard Molinar, initiated studies at Kearney Research and Extension Center to improve understanding of lygus biology in eggplant and refine sampling and management guidelines.

Studies utilized both caged and open field plots. The cages acted to expose eggplant to different population levels and to exclude lygus from plants. The open field studies were designed to track natural population development and their impact on yield. In these initial studies, Goodell and his team found that eggplant is very attractive to lygus and lygus does damage many flower buds, preventing fruit from forming. The team will focus on improving sampling and decision making for lygus, tailoring the information for the small-scale farmer.

IPM Alliances Win Over Growers

UC Statewide IPM Advisors have been leaders in many of the Pest Management Alliance (PMA) projects funded by the California Department of Pesticide Regulation to develop and demonstrate pest management systems that reduce pesticide risks. While targeted at grower groups and their PCAs, these Alliances rely heavily on UC IPM Advisors to provide technical expertise and organizational support as well as to write reports, conduct fieldwork, and carry out educational programs. UC IPM Advisor Carolyn Pickel has been closely involved in the PMAs for almonds, prunes, and walnuts.

"Seeing is believing" say the Farm Advisors involved in the Almond Alliance. Long-term demonstration/education sites were established in Butte, Stanislaus, and Kern counties to show growers that reduced pesticide spray programs work. No sprays were applied in some of these orchards for 4 years, and reduced-risk (less pesticide) sites had no increases in damage at harvest. Educational programs in demonstration orchards were popular with up to 125 neighbor growers attending, and participants got the message: Pesticide use in almonds went down with the greatest reduction in the last year (2001). The key to the program is winter sanitation, a practice that UC IPM has been promoting for 20 years.

In prunes, the PMA has focused on developing and demonstrating sampling plans/treatment thresholds that can help growers determine whether sprays are needed for each economically damaging pest. A major goal is to reduce dormant sprays. The project started by comparing side-by-side, reduced-risk monitoring protocols with grower standard practices. The Alliance has spent 2 years comparing a 5-minute search of mite populations to the more time-consuming presence-absence sample technique. The research showed that the two methods are highly correlated, resulting in PCA acceptance of the simpler, faster, 5-minute search technique.

The Walnut PMA has worked closely with researchers to refine pheromone techniques for controlling codling moth in walnuts. The Alliance has developed monitoring protocols to help growers and PCAs determine when pheromone confusion requires supplemental sprays; they have worked with researchers to learn how to use the new bi-sexual lure; and they have also field-tested and learned how to use a walnut blight model, XANTHOCAST.

These are just a few examples of how partnerships between commodity groups, University of California Cooperative Extension, University of California researchers, and USDA researchers improve understanding of IPM and enhance the adoption of IPM in California.

Attitudes toward IPM Examined in Cotton Grower Survey

Extension IPM Coordinator Pete Goodell initiated an IPM survey of cotton growers in 11 California counties during the spring and summer of 2001. The survey asked growers for information about their management practices for insect, mite, disease, nematode, and weed pests. In addition, growers were asked about pest management decision-making strategies such as the use and role of pest control advisers (PCAs), information sources, familiarity with and attitudes about IPM, and general farm characteristics. All items pertained to the year 2000 growing season.

Preliminary results, representing about 29% of the state’s year 2000 crop acreage, show that about 75% of the respondents used one or more PCAs who were affiliated with product suppliers, 41% used one or more independent PCAs, and 20% used both types of PCAs. About 78% of all growers received verbal reports from their PCAs at least once a week during the growing season, and 70% received written reports at least once a week.

UC IPM contracted with the Social and Economic Sciences Research Center (SESRC) of Washington State University to conduct the survey. Rose Krebill-Prather of the SESRC, formerly Evaluation Researcher with UC IPM, directed administration of the survey. Sonja Brodt, UC IPM Program Evaluation Specialist, is continuing analysis of the results. Her goal is to understand the attitudes towards and patterns of use of IPM strategies and to develop a methodology to compare and contrast IPM use in California cropping systems. Such information should contribute to our understanding of IPM adoption and suggest future research and extension efforts.

UC IPMers Help Coordinate a Learning Experience for Retail Nursery Personnel

Retail nursery personnel are a key source of pest management information for many home gardeners. In an effort to give them more in-depth information on integrated pest management, UC IPM and UC Cooperative Extension teamed up with the California Association of Nurseryman’s CCNPro (California Certified Nursery Professionals) group to present a continuing education program for retail nursery professionals. Held on August 13, the IPM in the Landscape program was sold out with 120 attendees.

The agenda featured hands-on and field activities including a diagnostic tour of problems in the UC Davis Arboretum, tours of drought tolerant and hardy plants in the Environmental Horticulture Department gardens, hands-on demonstrations of water and soil relationships, snail and slug management, and vertebrate management. Nursery staff were able to discuss, handle, and review products and tools in relationship to effectiveness and safety.

UC IPM staff involved in organizing this program included Mary Louise Flint, Steve Dreistadt, and Cheryl Reynolds. UC Cooperative Extension Advisors Chuck Ingels (Sacramento), Mario Moratorio (Solano/Yolo), Ed Perry (Stanislaus), Pam Geisel (Fresno), and Lynn Wunderlich (El Dorado) were key participants in the IPM in the Landscape Education Day.

Developing and Extending Information on Vine Mealybug,
A Recently Introduced Exotic Pest of Grape

The vine mealybug, Plannococcus ficus, is a newly introduced exotic pest of grapes in California. Its feeding results in cluster contamination, long-term yield loss and transmission of viral diseases and can cause severe losses in grapes. The pest was first identified infesting grapes in the Coachella Valley in 1994. In 1998 it spread to a few Kern and Fresno county vineyards.

In 2002, spread of the pest mushroomed. Infestations were detected in newly planted vineyards in Santa Barbara, San Luis Obispo, Sacramento, San Joaquin, Madera, Stanislaus, Napa, and Sonoma counties.

These new infestations all occurred on vines less than 3 years old and seem to be associated with shipment of nursery material. A team of UC researchers and extension specialists has been formed to develop monitoring and management methods and to stop the spread of vine mealybug to noninfested grape-growing counties.

During 2002, as a result of a UC IPM funded project directed by Kent Daane, several species of wasps that parasitize the mealybug were established and recovered at research sites. Chemical controls have been identified that are compatible with these parasitoids.

A sex pheromone has been isolated and synthesized by Jocelyn Millar at UC Riverside and is currently being utilized to detect the spread of vine mealybug. Extension activities to keep California grape growers abreast of new developments on vine mealybug management include the publication of the pamphlet Mealybugs in California Vineyards (ANR Publication 21612), extensive meeting presentations, trade journal publications, and radio and television broadcasts. The UC IPM Pest Management Guidelines for Grapes were updated in fall 2002 to include new management strategies for vine mealybug.

In November 2002, the UC IPM Program funded a special effort, coordinated by UC IPM Advisor Walt Bentley and including the team members listed below, to combat the pest statewide. The team will develop a method of detecting the pest in infested planting material in nurseries, to develop a treatment for dormant cuttings and green plant material being shipped for planting and to coordinate an educational program to inform growers about this serious pest.

Team members include Area UC IPM Advisors Walt Bentley, Lucia Varela, Cheryl Wilen, and Jim Stapleton; Researchers Kent Daane (UC Berkeley and Kearney Agricultural Center), Raksha Malakar-Kuenen (a post-doc at UC Berkeley), Jocelyn Millar (UC Riverside), Kris Godfrey (CDFA); and Farm Advisors Richard Coviello and Stephen Vasquez (Fresno), Jennifer Hashim and Dave Haviland (Kern), George Leavitt (Madera), Larry Bettiga (Monterey), Ed Weber (Napa), Chuck Ingels (Sacramento), Paul Verdegaal (San Joaquin), Mark Battany (San Luis Obispo), Rhonda Smith (Sonoma), and Bill Peacock (Tulare).

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