Almond Pest Management: Alternatives to Dormant Organophosphate and Pyrethroid Sprays

Bob Elliott

Department of Pesticide Regulation

1001 I Street
PO Box 4015
Sacramento, CA 95812-4015

(916) 324-4156
belliott@cdpr.ca.gov
(916) 324-9006

Executive Summary

Since the early 1980s, California almond growers have commonly used organophosphate pesticides (OPs) in the dormant season to control several key pests. Dormant OPs were promoted by UC farm advisors as safer to human health and the environment, less disruptive to beneficial insects and more effective than in-season sprays. However, since the 1990s, dormant OP use has raised concerns in California due to their detection in surface water (Bennett et al. 1998). Concentrations of diazinon in the Sacramento and San Joaquin River watersheds have been detected at levels high enough to be toxic to some aquatic organisms, thus threatening the health of downstream ecosystems. Pesticide Use Reports (PUR) indicate growers have responded to these concerns by using pyrethroid pesticides as a replacement for OPs. There is concern over the use of pyrethroids due to their potential for off-site movement. As a result the Department of Pesticide Regulation (DPR) proposes to add restrictions to most dormant season pesticide applications. In addition, the Regional Water Quality Control Board (RWQCB) is proposing a basin plan amendment to establish a Total Maximum Daily Load (TMDL) for diazinon in the Sacramento and Feather Rivers.

This proposal seeks to assist almond growers in understanding dormant spray regulations and TMDLs, and to provide information about reduced-risk alternatives to the use of dormant pesticides. The primary means of contact with growers will be field meetings in areas of high pesticide use as identified by the PUR. A grower-to-grower or pest control advisor (PCA) to grower format will be used whenever feasible. This cooperative effort will include the DPR, the Almond Board of California, progressive growers and PCAs, the University of California Cooperative Extension and the County Agricultural Commissioners.

Objectives

Assist almond growers in understanding requirements and environmental goals of Total Maximum Daily Loads (TMDLs) and proposed dormant spray regulations.
Use Pesticide Use Report (PUR) to characterize Organophosphate (OP) and pyrethroid pesticide use in three almond producing regions and identify watersheds where growers use high amounts of these pesticides. Use this information to assist in targeting specific areas or communities for outreach.
Provide outreach to growers and pest control advisors (PCA) on reduced-risk pest management practices. Identify feasible reduced-risk alternatives that could serve as regulatory options. Help growers make informed, effective pest management decisions that minimize the potential for surface water problems and comply with regulations. Use the PUR for subsequent analyses of OP and pyrethroid use in these watershed.

Justification

Under a settlement agreement between the Sacramento Valley Toxics Campaign and the State Water Resources Control Board (SWRCB) and the Regional Water Quality Control Board (RWQCB), DPR has committed to address water quality problems caused by dormant sprays. If after five years dormant sprays continued to cause toxic conditions in the Sacramento and San Joaquin rivers, DPR would use its authority to reduce concentrations to acceptable levels. Concentrations, particularly diazinon, still periodically exceed target levels aimed at preventing toxicity to aquatic organisms (Spurlock, 2002). As a result, DPR recently placed dormant sprays containing the active ingredient diazinon into reevaluation and will adopt regulations affecting the application of all dormant sprays. These use regulations are new to the farming community. DPR will provide the opportunity in the regulatory process for growers and others to propose alternative management practices that could be incorporated into the final regulations. Grower meetings during the first year will focus on helping growers gain an understanding of the pending regulatory issues (state and federal) and identifying feasible alternative management practices. These practices will be compiled into a document to help support development of regulations.
Analysis of data in DPR’s Pesticide Use Reporting system from the period 1992–2000 indicates that almonds have the largest use of dormant OPs, likely due to the extensive almond acreage. However, OP use in almonds has decreased over the last nine years. Factors affecting this trend include previous-season nut damage, use of other pesticides, or zero pesticide use. There are other factors that affect pesticide use trends such as pesticide and commodity prices, pest pressure, weather and grower perceptions. Identification of high OP users, within watersheds in the Sacramento and San Joaquin Valleys will help focus outreach in areas of greatest need. This will result in a prioritized list of regions for targeted outreach as described in Objective 3.
The Almond Pest Management Alliance (PMA), funded by DPR, has successfully demonstrated several effective reduced-risk practices currently being used by almond growers. Some or all of these practices could serve as tools to help growers comply with the regulations in part by reducing use of OPs and pyrethroids. The Almond PMA field workshops will provide guidance, outreach materials, and hands-on opportunities to help growers make informed pest management decisions and comply with new regulatory requirements. The PUR will be used for subsequent analyses of OP and pyrethroid use in the targeted watersheds

Overall Summary

About 6,000 growers in California produce three-quarters of the world's almonds on an estimated 530,000 bearing acres that extend from Chico to Bakersfield (Heintz 2001). Almond growers have relied on OP and pyrethroid insecticides to control the crop's key pests, San Jose Scale (SJS), peach twig borer (PTB), and navel orange worm (NOW). An effective practice to control PTB, SJS, and overwintering mites has been to apply an OP (mixed with narrow-range [superior] oil) during the dormant season (UC IPM 1985). The application can be made whenever the grower can get into the field between leaf fall and the green tip stage of almond development. Applications are made by ground using a tractor-driven air blast sprayer, or by air in wet years.

Biologically Integrated Orchard Systems (BIOS) promotes reduced-risk practices such as orchard sanitation, alterations in floor management, monitoring, beneficial release, and harvest timing. The standard control practice for San Jose Scale (SJS) is an oil spray plus an insecticide such as diazinon or chlorpyrifos. BIOS growers in Merced and Stanislaus counties have eliminated OPs from their dormant sprays, in part to preserve beneficial insects, basing their decision to treat on monitoring (CAFF Foundation 1995). Integrated Pest Management for Almonds (UC IPM 2002) recommends a superior-type oil during the dormant season, at proper rates with good coverage, to control SJS and other scale pests, as well as the eggs of European red mite and brown mite. Addition of an OP insecticide is only necessary if indicated based on monitoring.

Pesticide Use Report (PUR) analysis for the period 1992 –2000 shows dormant OP use in almonds has decreased while the use of two alternatives, dormant pyrethroids and no dormant insecticides, increased in the last nine years (Zhang et al. 2003). The trends were the same when measured by pounds of OPs per acre planted, percentage of total planted acres treated, and numbers of growers who applied dormant OPs. The reduction in dormant OP use appeared in all major almond-growing counties. Several factors may be responsible for this reduction such as cost of pesticides, weather conditions, level of pest pressure, and interest in reduced-risk farming practices.

The Almond PMA, initiated in 1998, has completed four years of work, in three distinct growing regions of the state, comparing the grower’s standard practice with reduced-risk practices (Heintz, 2003a). The PMA has demonstrated that reduced-risk practices, including no insecticide treatment, appear to be controlling pests below economic damage levels (Almond PMA Winter 2002-03). Further, extensive monitoring is identified as a key element in a reduced-risk program. Examples of reduced-risk practices include: 1) Dormant application with oil alone to control SJS. 2) Spray at bloom with reduced-risk products spinosad or Bacillus thuringiensis (Bt) to control PTB. 3) In-season spray in May with reduced-risk products spinosad, tebufenozide, or Bt to control PTB and NOW.

Approach and Outcomes

1. Grower Meetings

Grower meetings will be conducted through the PMA Workshops. We propose this forum to meet with growers to assist them in learning about the requirements of proposed dormant spray regulations and to understand TMDLs from DPR’s unique regulatory perspective. As regulators, DPR will bridge the scientific basis for the regulations with the need of growers for feasible options. Discussion will focus on management practices that will comply with the goals of the regulations. Certain practices have been developed and successfully implemented through the PMA and these will be the starting point for further discussion. The ideas generated will be documented and used to help support development of regulations.

2. PUR Analysis

DPR’s Pesticide Use Report (PUR) contains information on nearly all production agricultural use in California since 1990. Data are collected for each application and includes information such as the pesticide product, amount applied, the area treated, the grower’s identification code, the date of application, the specific field treated, and the application location to a square-mile section. Because the database contains grower and field identifications, we can examine not only pounds of pesticide used or area treated, but also the number of growers or number of fields that use different practices.

The PUR only tells what pesticides were used, not why they were used or how growers decided to spray or not or what pesticides to apply. Knowing what affects grower’s decisions could be important in helping us design a more effective outreach effort. To help us answer these kinds of questions we have funded work by Karen Klonsky, a University of California agricultural economist. She has started conducting focus groups and interviews with almond growers, PCAs, and farm advisors to learn how growers make pest management decisions.

This information, along with other information such as pesticide and commodity prices, will be used to develop a method to systematically help determine some of the main factors that affect grower pest management decisions. This information will be used to guide the development of outreach materials used in Objective 3.

In this proposal we intend to use the location data from the PUR to determine pesticide use in different watersheds and the distance to streams and rivers where high OP concentrations have been found. We can determine not only the amount of pesticides applied but also the number of growers responsible for most of the use. This information will allow us to determine the most important areas to focus our outreach efforts.

3. Grower Learning

The Almond PMA has received many compliments through its four years and has been shown to be effective in its outreach efforts (Heintz, 2003b). These outreach efforts collectively have combined to raise industry and public awareness of the project.

The PMA is now in its fifth and final year of DPR funding. Due in large part to the efforts of the Almond PMA, a baseline of awareness has been established and increased numbers of growers are showing interest in reduced-risk practices and are taking a proactive approach to increase their use. The focus of this objective is to take what we have learned from the PMA and use the techniques to help solve surface water problems. Through PMA Workshops, we will provide outreach on reduced-risk pest management systems, including pest monitoring techniques and an understanding of the pest dynamics in a particular orchard. The goal is to eliminate some OP and pyrethroid pesticide applications resulting in improved water quality. The PUR will be used for subsequent analyses of OP and pyrethroid use in these targeted watersheds

The Almond Board has proposed a comprehensive sixth year summary of the PMA results. DPR proposes to partner in development of this summary and implementation of the practices detailed. The following practices have been found effective through the PMA and will be the basis of the outreach materials developed through this grant.

No dormant insecticide treatment, based on monitoring results.
Dormant application with oil alone to control SJS, other scales and mite species that overwinter in the orchard as eggs.
In-season spray at bloom with reduced-risk products spinosad, or Bacillus thuringiensis (Bt) to control PTB.
In-season spray in May with reduced-risk products spinosad, tebufenozide, or Bacillus thuringiensis (Bt) to control PTB and NOW.
Winter sanitation program to control NOW
Extensive monitoring is the key to success of a reduced-risk program.

Impact Assessment

Objective # 1 The outcome will be educating the industry about proposed regulations and development of a document of feasible management practices for consideration in developing new regulations. If the regulations can be met through feasible field practices the water quality goals will be obtained that will benefit growers and achieve the same goals as intended by the regulations.
Objective # 2 PUR analysis will focus on identification of high pesticide use areas, by watershed, to target areas for outreach. Once established as a baseline, the PUR information can be used in subsequent years as a measure of the success of the outreach program by further PUR analyses.
Objective #3 Outreach deliverables include a guidebook (systems approach to pest management), on-site training at individual grower locations, hands-on field days and other reference material (i.e., fact sheets, flip cards for pest ID). Measurement of the success of this objective will be assessed through the PUR and interviews with individual growe

Literature Cited

Almond PMA Newsletter Winter 2002-03. Almond Pest Management Alliance Enters Fifth and Final Year.

Bennett, K., C.E. Nordmark, J. Schuette, H. Fend, J. Hernandez, and P. Lee. 1998. Occurrence of aquatic toxicity and dormant-spray pesticide detections in the San Joaquin River watershed, Winter 1996-97. Environmental Hazards Assessment Program, Environmental Monitoring Branch, Department of Pesticide Regulation, Sacramento, CA. EH 98-02.

Community Alliance for Family Farms (CAFF) Foundation 1995. BIOS for Almonds: A practical guide to biologically integrated orchard systems management. 104p.

Heintz, C. 2003a. Pest Management Alliance Project Final Report Year 4, “To Promote a Reduced-Risk System of Almond Production Through Alternative Practices”. February 13, 2003. Almond Board of California.

Heintz, C. 2003b. PMAP seminar presentation to DPR staff, entitled Almond Pest Management Alliance 1998-2003. January 13, 2003. Department of Pesticide Regulation, Sacramento, CA.

Heintz, C. 2001. Update of the Pest Management Evaluation for the Almond Industry. November 1, 2001. Almond Board of California.

Spurlock, F. 2002. Analysis of diazinon and chlorpyrifos surface water monitoring and acute toxicity bioassay data, 1991-2001. Environmental Hazards Assessment Program, Environmental Monitoring Branch, Department of Pesticide Regulation, Sacramento, CA. EH 01-01.

University of California Statewide Integrated Pest Management Project (UC IPM) 1985. Integrated Pest Management for Almonds. First edition. Division of Agriculture and Natural Resources University of California, Oakland, CA. Publication 3308.

UC IPM. 2002a. Integrated Pest Management for Almonds. Second edition. Division of Agriculture and Natural Resources, UC Davis, CA. Publication 3308.

Zhang, M., L. Wilhoit, L. Ross, and C. Geiger. 2002. Dormant season organophosphate use in California almonds. Pest Management Analysis and Planning, Pest Management and Licensing Branch, Department of Pesticide Regulation, Sacramento, CA. PM 02-XX

Timetable

Objective #1 Activities include meeting with growers to educate them about proposed dormant spray regulations. This will take place in the first 8 to 10 months of the project to coincide with the public comment period for the regulations.

Objective #2 PUR analysis activities will take place in the entire 24 months of the project. Information will be used to target outreach (Objective #3).

Objective #3 Outreach activities will be on-going in the second 12 months of the project to coincide with the sixth year summary of the PMA.

Major Participants

The project coordinator, Mr. Bob Elliott, is coordinator of DPR’s Pest Management Grants program. Mr. Elliott received his B.S. in Horticulture from California State University at Fresno. He works with commodity groups, growers, university researchers, non-profit groups, government agencies and others to help promote adoption of reduced-risk pest management practices. Previous work included interim coordinator of DPR’s Food Safety Program,and other activities relative to California’s pesticide regulatory program. Other experience includes work as a research technician for the Fresno County UC Cooperative Extension, Pest Control Advisor for Wilbur Ellis Company, and an Agricultural Biologist for the Yolo County Department of Agriculture. Bob will work closely with the Almond Board, UC Cooperative Extension, the Almond PMA, and DPR researchers to coordinate project activities and meet the objectives of the project.

The primary collaborator Chris Heintz, is Director of Research, Technology and Education for the Almond Board of California. Ms. Heintz received her B.S. and M.S. degrees in Food Science and Technology from the University of California, Davis. After working five years in the Department of Pomology at UC Davis, she served with Blue Diamond Growers and then Rice Growers Association until 1996 when she accepted a position with the Almond Board. Ms. Heintz has managed the areas of product development and technical services. She has co-authored several scientific publications, taught college-level nutrition classes and developed more than a dozen new products sold domestically and internationally. Currently she directs the Almond Board’s $1.4M research budget and is Principle Investigator of the Almond Pest Management Alliance, responsible for the overall management of the Almond PMA. Chris will bring the resources of the Almond PMA to the project.

The primary collaborator Walt Bentley, is UC IPM Area Advisor at Kearney Agricultural Center. Mr. Bentley received his B.S. in Biology from California State University Fresno and his M.S. in Entomology from Colorado State University. Professional experience includes Entomology Farm Advisor, Kern County UC Cooperative Extension, Senior Entomologist, Division of Bio Control, Colorado Dept. of Agriculture and Graduate Research Assistant, Colorado State University. Mr. Bentley has served as Principle Investigator on several research projects supported by DPR, the Almond Board, the Walnut Marketing Board, the Tree Fruit Agreement, CA Table Grape Commission, and others. Walt will bring his extensive entomological background and his experience as Almond PMA Advisor to the project.

The collaborator, Dr. Minghua Zhang (MS in quantitative agronomy and PhD in ecology from the University of California at Davis), leads the Agricultural GIS Laboratory (AGIS Lab) in the Dept. of Land, Air and Water Resources, UC Davis. One of the academic objectives of her Lab is to conduct researches for understanding agricultural environmental compatibilities on spatial functional relationships between the chemical uses in agriculture and their impacts on water quality, applying GIS and remote sensing techniques. Dr. Zhang has worked with the Pesticide Use Report (PUR) database since 1990. In 1999, Dr. Zhang was granted a project from the California Department of Pesticide Regulation for assessing the data quality of PUR for spatial attributes. Dr. Zhang served as a member of the external PUR advisory committee in the last two years and also works as a senior environmental research scientist at DPR. Minghua will bring experience from a previous analysis of the PUR database to identify locally-optimized ecological farm management practices

The collaborator Marshall Lee is Supervising Senior Environmental Research Scientist at DPR, with responsibility over the Department’s Surface Water program. Mr. Lee has a master's degree in entomology from the University of California at Davis and has extensive experience in water quality monitoring and in the development and implementation of programs for reducing pesticide runoff into surface waters. Marshall will bring experience in water issues and developmental oversight of the dormant spray regulations.

The collaborator Dr. Larry Wilhoit, is Senior Environmental Research Scientist at DPR, with primary responsibility over DPR’s Pesticide Use Report (PUR) database. Dr. Wilhoit received an undergraduate degree in physics and math and later a PhD in entomology from UC Berkeley. One of his first projects at DPR in 1993 was to find the pesticides used on several crops. At the time, the PUR database was somewhat neglected and contained several significant errors. Dr. Wilhoit thought it was an important resource and has been instrumental in improving the structure and quality of the data collected. Larry will bring his work experience with the PUR database to the project.

Project Budget

Funding Request
Funding Requested	Other Funding*	Total Funding
$40,000	$58,053	$98,053

*DPR in-kind support.