A monthly report on pesticides and related environmental issues

Issue No. 128, October 1996

Open Forum:
In an attempt to promote free and open discussion of issues, The Agrichemical and Environmental News encourages letters and articles with differing views. To include an article, contact: Alan Schreiber, Food and Environmental Quality Laboratory, 100 Sprout Road, Richland, WA 99352-1643, ph: 509-372-7324, fax: 509-372-7460,
E-mail: ebechtel@beta.tricity.wsu.edu or aschreib@beta.tricity.wsu.edu

In This Issue

News and Notes Available Reports
College Seeks New Name Forum Participants Learn About
Major Pesticide Issues
Comparisons of Conditions
for WPS Exceptions
Cover Crops Reduce
Leafhoppers, Weeds in Grapes
Future of Weed Science
Research and Extension
at WSU
Fungicides for Powdery Mildew
Undergo Efficacy Trials
Acceptable Risk Rears
Ugly Head in FQPA
Officially Unofficial
Plastic Pesticide Container
Collection Requirements
Federal Issues
Editorial WSU Offers Pesticide Education

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News and Notes

Note: The AENews is now accessible from the World Wide Web via the Washington State Pesticide Page. The address for the page is:

Enter this address carefully, paying close attention to punctuation and spacing (no spaces between parts of the address). Some readers may experience difficulties accessing the site. These are believed to be related to the Internet and to on-line services, not the web site. If you are having a problem accessing the web page, please inform Eric Bechtel (ph: 509-372-7378, fax: 509-372-7460, E-mail: ebechtel@beta.tricity.wsu.edu

Trial subscriptions to database offered

The Pesticide Information Center has received a number of requests for subscriptions to its new database, the Pesticide Information Center On-Line (PICOL). Other system offerings attracting users include the Tolerance Database, the Washington State Commission on Pesticide Registration web page and the Pesticide Notification Network. The Pesticide Information Center pro-rates database subscription costs on a quarterly basis. For the rest of 1996, the system is available for a cost of $25. Interested parties may obtain more information by pointing their web browsers to the PICOL home page at: http://picol.cahe.wsu.edu or by calling the Pesticide Information Center at 509-372-7492.

Record wheat crop for Washington

Washington produced a record wheat crop in 1996, exceeding the previous record set in 1993, according to the Washington Agricultural Statistics Service (WASS). The 1996 wheat crop totaled 182.7 million bushels, 19 percent more than the 1995 crop and 6 percent more than the previous record of 177.6 million bushels produced in 1993.

Winter wheat, with record yield and production, was the major contributor to the record crop. The yield for 1996 winter wheat was 70 bushels per acre, and total production was a record 164.5 million bushels.

Spring wheat production totaled 18.2 million bushels, 11 percent less than 1995. The yield per acre averaged 46 bushels. Harvested acreage was 395,000, compared with 445,000 acres harvested in 1995.

Total wheat production for the Pacific Northwest set a record at 369.5 million bushels, 16 percent more than 1995.

Barley production in Washington totaled 27.3 million bushels for 1996, an increase of 31 percent from last year. The harvested acreage showed a strong increase - 52 percent more than last year - but the yield of 62 bushels per acre was down 10 bushels from 1995.

WSCPR November meeting

Nov. 20, 10 a.m

Main conference room

Weyerhaeuser Technology Center

Federal Way, Wash.

Attendees must communicate with Catherine Daniels as soon as possible to secure name badges required for admittance. Information and directions may be obtained by contacting Catherine Daniels at 509-372-7492 or cdaniels@beta.tricity.wsu.edu

Children to be focus of EPA FQPA funds

EPA will spend an additional $30 million that Congress has appropriated for fiscal year 1997 for the Food Quality Protection Act and the Safe Drinking Water Act. The agency should "first focus on ... scientific and regulatory policies and other actions which have the largest implications for infants, children and other at-risk populations," according to language in the omnibus spending bill recently approved by Congress.

The bill went on to recommend that the additional revenues also go for "approval of new pesticides and the review of existing pesticides, as these are areas where the agency may best attain immediate risk reduction." EPA was directed to spell out in an operating plan how it will spend these funds.

Additional $10.2 million reserved for residue data monitoring

Congress also appropriated $10.221 million for EPA "to support the collection of pesticide residue data from industry and state sources for the agency to use in its risk assessment activities," an action that may replace the funding cut from USDA's pesticide data monitoring program.

The bill said further that congressional conferees "note in this regard that the recently authorized Food Quality Protection Act mandates that residue data collection activities be improved and that sampling of foods most likely consumed by infants and children be increased."

However, Congress probably did not intend for this money to be used by USDA - at least in the short term - to run its own pesticide residue data collection program, because of the following proviso in the bill:

"To this end, the conferees direct that EPA enhance its in-house data collection abilities so as to conduct this program in a manner which does not result in transfer of these funds to any other federal agency. The conferees further note that this funding is being provided for transitional purposes only in the initial stages of implementation of this new law, and expect future funding to be provided by a more appropriate federal agency."

It was unclear exactly which would be the "more appropriate federal agency" in the future - USDA, EPA or some other government agency.

From Pesticide and Toxic Chemical News.

WSCPR seeks proposals

The Washington State Commission on Pesticide Registration is seeking proposals to fund projects that will result in obtaining or maintaining a pesticide registation in the state of Washington. For information on obtaining assistance from the WSCPR, contact Catherine Daniels at 509-372-7492 or by E-mail at cdaniels@beta.tricity.wsu.edu.

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College seeks new name

Constituents of the Washington State University College of Agriculture and Home Economics have expressed their desire for a change in the name of the college to one that would be both more inclusive of extension, research and teaching programs and more descriptive of the college's mission to the public. Many also have expressed their desire to update the term "Home Economics" to reflect the broader range of disciplines now covered by this group.

A committee was formed from the faculty and staff senators of CAHE to consider possible names and make a recommendation to the dean. The CAHE Name Change Committee met and narrowed the names to five choices. Among the considerations going into the choices selected were the following:

1) to keep "agriculture" in the name to recognize important clients in this area

2) to replace "home economics" with a more current and inclusive descriptor

3) to include with a single term those constituents involved in environmental and natural resource sciences

4) to provide a name that would be inclusive for everyone working within the college and descrip- tive for students, growers, consumers and other clients

5) to keep the name relatively short

The term "life sciences" was rejected because of its traditional association with the basic biological sciences. Adding "applied" to the name might alleviate this, but it would add to the length. Also, not all constituents are doing applied work.

Among the five choices selected were the following:

1) College of Agricultural, Family and Consumer Sciences,

2) College of Agricultural, Human and Environmental Sciences,

3) College of Agricultural, Human and Natural Resources,

4) College of Agricultural, Human and Natural Sciences, and

5) College of Agricultural and Human Sciences.

The CAHE Name Change Committee submitted the five names to faculty and staff in order to learn whether any strong feelings exist for or against any name. Results of this opinion poll will be a major factor in the final recommendation to the dean.

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Comparisons of conditions
for use of WPA exceptions

Conditions Early Entry
w/ No Contact
Short Term
Limited Contact
with treated
Prohibited Allowed Allowed for hands, forearms, ankles Allowed for hands, forearms, feet, ankles Allowed
Hand labor Prohibited Prohibited Prohibited Irrigation
tasks only
Time limit
(in 24 hr)
No time limit 1 hr limit/
8 hr limit/
8 hr limit/
No time
Need must be
unforeseen with potential for significant loss
Not required Required Required Required Required
Time of
earliest entry
after end of application
4 hrs & after
ventilation criteria met
4 hrs & after
ventilation criteria met
4 hrs & after
ventilation criteria met
4 hrs & after
ventilation criteria met
4 hrs & after
ventilation criteria met
workers of
exception use

This table comparing various conditions for use of worker protection standard exceptions was compiled by Judy Smith at USEPA Headquarters. Questions regarding this information may be directed to Allan Welch, Worker Protection Coordinator, United States Environmental Protection Agency Region 10, 1200 Sixth Avenue, Seattle, WA 98101, phone: 206-553-1980.

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The future of weed science
research and extension at WSU

...James J. Zuiches

This article is an excerpt from a presentation Dr. Zuiches prepared for the annual meeting of the Washington State Weed Association, Nov. 6-8, 1996, Yakima, Wash.

I appreciate the opportunity to communicate to participants in the Washington State Weed Extension Association about the vision and future of weed science research and extension programs at Washington State University and in the Pacific Northwest. Although I am not a weed scientist by training, I have had the good fortune to be involved in the administration of weeds research and extension activities since my first appointment in 1982 as Associate Director of the Cornell University Agricultural Experiment Station. During the eight years that I served as the Director of the Washington State University Agricultural Research Center, I continued to monitor closely the research and extension activities focusing on the management, control and educational programs associated with weeds. As vacancies occurred through retirements or resignations, I became actively involved in planning and the replacement of scientists to support Washington weed management programs.

To prepare these remarks, I solicited information from our faculty and unit heads involved in weed research, extension and teaching programs. I want to acknowledge the assistance of Robert Parker, Kim Patten, Gary Piper, Joe Yenish and Alan Schreiber. These faculty members are conducting the programs that benefit the industry now. In addition, we are searching for two faculty members to replace Kassim Al-Khatib, who resigned recently from the Mt. Vernon Research and Extension Unit to move to Kansas State University, and Patrick Fuerst, who resigned recently from his position at Pullman.

None of our work exists in isolation. The program in weed research and extension has been conducted in partnership with the USDA Agricultural Research Service. In particular, Alex Ogg, Frank Young and Rick Boydston have provided significant support for our weed programs in this state. Additionally, we partner with Oregon and Idaho in many areas. Presently, we rely on Oregon State University expertise in forestry weed programs. We also rely on research being conducted on some of the horticultural crops from Oregon State University and some of the major irrigated crops from the University of Idaho and Oregon State University. We coordinate work throughout the Pacific Northwest (PNW), to avoid duplicating effort.

WSU also has a representative on the Washington State Noxious Weed Control Board and has contributed to the coordinated state agency noxious weed control budget decision package.

The weed research and extension program could not operate with simply the appropriation of state funds to agricultural research and Cooperative Extension. We have had significant support from commodity commissions, from chemical companies and the chemical industry, and from numerous growers, who assist as cooperators and participants in field research. Many agencies, such as the Bureau of Land Management, the Forest Service, US Fish and Wildlife Service and the Bureau of Indian Affairs, to mention a few, have also funded weed management programs. Additionally, the Washington State Commission on Pesticide Registration (WSCPR) supports field residue studies required in the analysis of alternative chemicals for use in weed management. Lab analysis is accomplished and completed through the Food and Environmental Quality Lab (FEQL) and work that Alan Schreiber provides to IR-4.

Our vision for future research and extension efforts is that they would be a blend of control methods. No one methodology, whether chemical, cultural, biological, biotechnological, or mechanical can effectively control and manage weeds. We need a program that combines mechanisms and creates an integrated weed management system (IWM). Integrated management is the deliberate selection, integration and implementation of weed suppressive measures on the basis of predicted economic, ecological and sociological consequences (Gary Piper 1991). Integrated management recognizes that weeds are plants too; they exist in an ecosystem managed for agricultural production or as a public land, whether for recreation, forestry or range. In this ecosystem acceptable management strategies will be those that are practical, efficacious, economical and productive. Our vision is that weed science will be an integral part of plant science programs.

An excellent example of the integration of weed science and entomology is the program of biological control. Bio-control is the deliberate use of insects, mites, plant pathogens and vertebrates to suppress noxious plant species. Bio-control strives to reduce weed abundance by increasing the stress placed on the weed by natural enemies. The objective is not eradication but reduction of population densities to tolerable levels. Bio-control is cost effective and environmentally safe and represents a major initiative of WSU.

In Washington state all biological control of weed projects have involved exotic plant species. Fifty percent of state weeds and all weeds on the state noxious weed list have been accidentally or intentionally introduced from various countries throughout the world. To biologically control noxious plants, destructive bio-agents must be procured from the weed's native home, screened to ensure that they will damage only target weeds, and when approved by state and federal regulatory agencies, released against the weeds. Biological control mechanisms can be an effective weed management method in agricultural areas and in non-cropland areas. It is not a silver bullet; successful management requires integration of biological, chemical and other control methods.

Attempts to biologically control weeds in Washington date back to 1948, when several insects were released in the state for suppression of St. Johnswort, a serious rangeland weed. During the last four decades, 60 different biological control agents have been enlisted to combat 23 exotic weed species. Forty-five of these bio-agents were introduced by Gary Piper, a WSU entomologist, from 1979 to 1996. Seventy-seven percent of all the bio-agents introduced into Washington have established and are contributing to noxious weed control. Populations of weeds such as rush skeleton weed, musk and plumeless thistle, poison hemlock, St. Johnswort, and pansy ragwort have been severely impacted because of biological control agent establishments.

During the recent Badger Canyon herbicide drift issue, WSU conducted research that addressed directly the causes of drift.

WSU extension activities include traditional grower, dealer, public agency and applicator training in weed management in crops, IPM, drift reduction, plant identification, herbicide resistance, groundwater and other safety and environmental issues as they relate to herbicides. WSU Extension is the primary resource for PNW aquatic weed control. The university writes or contributes to applicator training manuals and grower guides and to videos on weed management topics. Extension personnel are expected to know how to control weeds in all 230 of the state's crops plus control weeds in wetlands, game refuges, roadsides, urban settings and other sites.

We have had some major successes. Control of Canada thistle in asparagus was a difficult problem, but cooperation between Rick Boydston, WSU, and the Washington Asparagus Commission led to the 1995 approval of Stinger on asparagus. Based on estimates from a processor and the commission, as much as 10 percent of the Washington asparagus crop would have been lost to weeds, had Stinger not been approved. The annual value of the lost product was $5 million, with an additional $15 million in added value. Registration of Stinger led to a combined farm gate and processed commodity value in one year of $20 million. This $20 million, which benefits one state commodity, is greater than entire state funding of the Agricultural Research Center.

The second example consists of registrations for herbicides on minor crops such as dry peas, chickpeas and lentils. The IR-4 program has obtained approval for Round-Up on peas, lentils and chickpeas. The IR-4 program, led by Schreiber, is completing work on MCPA for peas. Loss of MCPA on peas would have forced growers to use a product that is less effective and 10 times more expensive.

The IR-4 project provides the only method for herbicide registrations on minor crops in Washington. Again, cooperation between ARS, WSU, field researchers and FEQL is essential for this success. We also owe a debt of gratitude to the agricultural industry for the establishment of the Washington State Commission on Pesticide Registration (WSCPR). During the past year the WSCPR supported 14 weed research projects representing a total of $290,000 in state and matching funds. Projects focus on peas and lentils, raspberry, mint, hops, rhubarb, onion, seed crops such as carrots, parsley and parsnips, food carrots, grass and clover seeds. This work would not have been done without the collaborative efforts of the WSCPR, WSU and ARS. We expect to see our first new registrations due to these efforts before the 1997 growing season. We have more than $300,000 in funds to support 1997 projects. I encourage those interested in discussing pesticide registration projects to contact Alan Schreiber at FEQL, WSU Tri-Cities, 509-372-7324.

Noxious weed management during nearly the last 75 years has been inadequate, and it will take time to repair the damage, the Noxious Weed Control Board indicated recently. I am concerned that this inadequacy will continue in our agricultural research and extension programs. We have, however, developed a proposal for the management and control of pests. Weed management is an important part of the package. We hope to strengthen our proposal and take it to the Legislature in fiscal year 1999. In our current request to the Legislature, the CAHE and WSU have put forward a major request for infrastructure improvement. To be successful, we need not only the faculty but also the farm and field equipment necessary to conduct research and extend it to the audiences with which we work. WSU is requesting $8 million in omnibus equipment support for the entire university. If funded, $2 million could be dedicated to the CAHE. We anticipate using $1 million each biennium for five biennia, to replace farm and field equipment.

University laboratories and research capacity also need improvement. The CAHE is requesting a new plant sciences facility. We would double the square footage for laboratories, both teaching and research, and a new plant sciences building would provide state-of-the-art scientific program capacity.

Our future will require research, educational and regulatory agency coordination. It will require the latest technologies and the application of biotechnology to weed management. It will also require expanded use of natural enemies and biological control strategies. Most importantly, it will require continued cooperation and partnership between the agricultural industry and WSU research and extension programs. I have appreciated this industry support and look forward to continued support as we work to maintain permanent and effective agriculture in Washington.

Dr. James J. Zuiches is dean of the WSU College of Agriculture and Home Economics

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Available Reports

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`Acceptable risk' rears ugly head
in Food Quality Protection Act

...Erika Schreder

The Food Quality Protection Act of 1996, which overhauls the nation's pesticide regulations, has been touted by the Clinton administration as a major environmental victory and decried by grassroots activists as flawed legislation. The law is the outcome of a bipartisan compromise. The result is a mixed bag that embodies a forward-thinking approach in several arenas, but repeals the protective Delaney Clause that prohibited cancer-causing pesticide residues in processed food. Following are some of the key provisions of the new law.

Repealing the Delaney Clause
The law replaces the zero-tolerance Delaney Clause with a risk-based standard that applies to both raw and processed foods. The new "reasonable certainty of no harm" standard is historically translated as an additional lifetime risk of one in a million. Of major concern is the exemption clause that allows the risk to be doubled when the Environmental Protection Agency (EPA) determines that a lower tolerance level will cause "significant disruption to domestic production of an adequate, wholesome, and economical food supply." The new standard lacks the certainty of Delaney, which espoused a precautionary approach of allowing no cancer-causing substances in our processed food. However, it could provide more protection in several ways. Most importantly, it sets tolerances for both raw and processed foods and considers toxic effects beyond cancer. EPA must also consider multiple exposures to a single pesticide, as well as available information on exposure to a range of chemicals with the same type of toxicity.

Protection of infants and children
For the first time, EPA is required to make special consideration of the health of infants and children. It must consider available information on both extra exposure to particular foods and special vulnerability. In addition, the margin of safety can be increased for residues that may harm children either before or after birth.

Endocrine disrupting chemicals
EPA is now empowered to require testing on endocrine effects of pesticides for use in setting tolerance levels. This provision is already under attack. Members of the Senate are attempting to block funding for EPA regulatory activity on endocrine disrupting pesticides, pending the completion of a National Academy of Sciences study.

Integrated Pest Management (IPM)
IPM is defined under the new law as "a sustainable approach to managing pests by combining biological, cultural, physical and chemical tools in a way that minimizes economic, health and environmental risks." Strikingly, the law also mandates federal agencies to use and promote IPM. Although this definition doesn't require a reduction in pesticide use, the mandate may force federal agencies to reassess their pest control practices.

Consumer right to know
This law's version of right-to-know is the annual publication and distribution by the EPA of a pamphlet describing the risks and benefits of pesticides. Information must also be posted in grocery stores selling food treated with pesticides for which exemptions were granted. Of course, EPA will be subject to intense pressure from industry as it develops these informational pamphlets.

Preemption of local regulation
States are now prohibited from setting residue tolerance levels that are stricter than national standards. "California is noted for having tougher pesticide standards than the federal level," said Jeanne Merrill, a field organizer with San-Fransisco-based Pesticide Watch. "Now Congress is stripping our state's and others' ability to further protect public health by preempting state law."

When all is said, this legislation misses the point of replacing toxic pesticides with safe alternatives. As Jay Feldman, director of the National Coalition Against the Misuse of Pesticides, said, "While the compromise tightens previous bills by creating additional hurdles, these are more detours on the road to further food contamination." We will be sure that our food is safe, when we move to safe and sustainable practices for producing food.

From the Washington Toxics Coalition newsletter, Alternatives.

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Officially Unofficial

...Alan Schreiber

"Officially Unofficial" is a regular feature that may include information considered inappropriate by some.

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Forum participants learn
about major pesticide issues

...Eric Bechtel

The FQPA was one of several pesticide-related topics addressed at an all-day Pacific Northwest Pesticide Issues forum held October 17 at the Pasco Red Lion. Some 125 forum participants learned about the act, endocrine disruptors, cholinesterase testing and genetically modified plants.

Alan Schreiber, Agrichemical and Environmental Specialist with the WSU Food and Environmental Quality Laboratory (FEQL), said the act is "the most important pesticide issue in the last 10 to 15 years", but not even the EPA understands its provisions completely or knows for certain how they will be implemented.

Schreiber said the act is a laundry list of virtually everything everyone ever wanted on pesticides. While it eliminates the Delaney Clause, which established a zero tolerance for cancer-causing residues in processed foods, the act contains provisions he claims are worse than what the act removed.

Among provisions Schreiber listed were the addition of a 10-fold greater safety factor in determining tolerances, required tolerances for Section 18 emergency exemptions, and a requirement for EPA to look not only at a pesticide's potential to cause cancer but also its potential to disrupt hormonal function and cause other negative health effects.

Increasing the safety factor in setting tolerances, Schreiber said, will eliminate many registered pesticides and block new registrations. He said seven registrations of interest to the Pacific Northwest have been blocked already and that the new tolerance requirement has placed many Section 18 requests on hold.

Ted Maxwell, Registration Manager for the WSDA Pesticide Management Division, echoed Schreiber's concerns regarding the act. Regarding Section 18s, Maxwell said, the agency is waiting to see how the EPA establishes tolerances. "We don't know whether to be concerned or scared to death."

Endocrine disruptors
Also waiting to be seen is how the EPA intends to interpret the FQPA provision requiring examination of pesticides for their effects on the endocrine system, the bodily system responsible for hormone production. Recently published books and magazine articles claim man-made chemicals and pesticides are disrupting normal hormonal function and leading to lower sperm counts and reduced fertility among human males.

Allan Felsot, Environmental Toxicologist at FEQL, discounted as minimal the impact of man-made chemicals and pesticides on hormonal function. He took data used to indicate reduced sperm counts in human males and showed statistical analyses of these same data that demonstrate sperm counts are not declining but are stable or even increasing. Felsot also cited research demonstrating no correlation between fertility and sperm count.

Regulatory status of the endocrine/hormone issue
In discussing EPA plans for dealing with the endocrine disruption issue in implementing the FQPA, Marie Jennings, USEPA Pesticide Program Manager for Region 10, told forum participants that the agency is in a data gathering mode. It is treating the endocrine disruption issue as it treats any environmental issue. The agency has prepared an initial problem statement. It will study the history of the issue and conduct studies and assessments before deciding on a final implementation strategy. The agency has established the Endocrine Disrupting Screening and Testing Advisory Committee, which is presently developing an effort to study hormone disruptors. Within two years, the agency is to have developed and reviewed a screening program. Within four years, the agency must report on its efforts before Congress.

Cholinesterase testing
Although not mandatory in Washington, cholinesterase testing for farmworkers helps reduce liability, increases safety awareness, exposes problems with chemical handling and use of personal protective equipment, and eases the minds of both workers and employers, according to Phil Hull, Labor Management Specialist for the Washington Growers League. Hull said the league favors testing but wants to see better testing, alternative testing methods and better education for clinics in interpreting results.

According to Dr. Sheldon Wagner, Professor of Clinical Toxicology at Oregon State University, testing for low cholinesterase levels is the primary way to diagnose organophosphate pesticide poisoning. Cholinesterase is a naturally occurring enzyme associated with nerve function.

Wagner said many variables exist in cholinesterase testing that can make interpretation of results difficult. Errors may occur in the laboratory, or the tested person may be among the three in every 1,000 individuals who naturally display abnormal levels of cholinesterase in their blood plasma. Other testing variables may occur from congenital problems, liver disease, hepatitis and cancer. Very young and very old individuals often don't display normal variations. Pregnancy, birth control pills and several drugs, including nicotine and cocaine, may also affect results.

Wagner said he prefers having at least two preexposure baselines, and he recommends conducting tests of both red blood cells and plasma for cholinesterase levels. Also, because not every poisoning will result in immediate physical illness, he recommends preseason and postseason tests to reveal any long-term exposure and problems with chemical handling or use of protective equipment.

Genetically modified plant protectants
Advances in biotechnology, according to Schreiber in a presentation on genetically modified crops, could help reduce the need to apply chemical pesticides, including many organophosphate, carbamate and pyrethroid insecticides. Biotechnology, he said, promises to be the foundation of the next green revolution.

Schreiber said that Flav-r Sav-r tomatoes, soybeans and canola resistant to Roundup herbicide, and cotton and potatoes genetically protected with Bt against insects are already commercially available. He said to expect future genetically engineered crops such as potatoes resistant to Colorado potato beetle and potato leafroll virus; corn, sugarbeets and rapeseed resistant to Roundup; and disease-resistant wheat.

Eric Bechtel is editor of research publications at the Food and Environmental Quality Laboratory.

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Cover crops reduce
leafhoppers, weeds in grapes

...Muhammad A. Bhatti and Alan Schreiber

Cover cropping has received considerable attention as an IPM tool for enhancing natural control of arthropod pests, weed suppression, and for increasing soil fertility. Vineyard managers throughout the Pacific Northwest are rediscovering the benefits of growing cover crops as an IPM tactic. It is becoming apparent that cover crops can be a powerful tool in the broader management of a vineyard agroecosystem.

The Food and Environmental Quality Lab has received a three-year grant from the USDA to determine the multiple site-specific effects of cover crops on pest abundance, crop nutrients, and crop yield and quality of wine grapes under various management systems. The project, a cooperative effort between California and Washington scientists, involves large-scale experiments in grower vineyards. For the last two years, researchers have consistently observed a significant impact from cover crops on the population dynamics of leafhoppers and beneficial insects and spiders. Results regarding weed suppression in the row middles are promising. Information in the report includes some highlights on the distribution and abundance of leafhoppers in conventional and organic grape production systems with or without cover crops.

In 1995, at a vineyard in the Yakima Valley near Prosser, three cover crop treatments were established in a conventionally managed Merlot and an organic Johannesburg vineyard. Both vineyards were sprinkler irrigated. The organic vineyard was kept free of synthetic pesticides or fertilizers during the growing season and for at least 12 months prior to planting cover crops. The cover crop treatments included: 1) perennial rye grass, 2) a mixture of legume and grass (rye and hairy vetch), and 3) no cover (resident vegetation). Leafhoppers were sampled throughout the season in all plots by counting the nymphs in the canopy and by using sticky traps.

Sampling of grape canopies in the organic vineyard showed leafhopper population density two to six times less than in a vineyard with conventional management practices of weed suppression and broad spectrum pesticides. Results of this research corroborate findings of other studies comparing arthropod populations in organic and conventional vineyard management systems. Numbers of leafhoppers (both nymphs and adults) were reduced in the organic vineyard as the season progressed to July and August (Fig.1). Also observed in the organic vineyard were increased populations of beneficial arthropods like damsel bugs, minute pirate bugs and spiders. In the conventionally managed vineyard, leafhopper population density increased significantly and reached treatment threshold in August (Fig. 2). In order to control the leafhopper population and avoid further damage to grapevines, the grower applied imidacloprid (Provado).

In both vineyard management systems, the lowest leafhopper (nymph and adult) density in grapevine canopies occurred in plots having a combination of rye and hairy vetch as ground cover. The second lowest densities were in grapevines with rye as ground cover (Figs. 1 & 2). The greatest leafhopper density was observed in grapevines with no ground cover other than resident vegetation. Although samples were not analyzed for spider densities, the number of spiders collected from plots with ground cover appeared greater than for those plots with no ground cover. Reductions in leafhopper population density are associated with enhanced activity of beneficial arthropods and a cover crop in the row middles as an alternative host.

Findings from other large-scale studies of drip or sprinkler irrigated, conventional and organic vineyards at a different location followed a similar pattern: presence of rye and hairy vetch resulted in significant reductions in weed infestation and leafhopper density.

Despite encouraging early results, several questions remain to be addressed in order to understand and predict the impact of cover crops on insect abundance, vine nutrient and water status, and grape yield and quality. The researchers plan to continue their work on the same vineyards during the 1997 season and will attempt to expand interdisciplinary involvement to examine the impact of cover crop systems on soil fertility and vineyard water use.

Dr. Muhammad A. Bhatti is a research associate at the Food and Environmental Quality Laboratory working with Dr. Alan Schreiber.

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Fungicides for powdery mildew
undergo efficacy trials

...Anne Morrell

Powdery mildew, caused by the fungus Uncinula necator, is the most important pest problem in Washington wine grapes. All commercial wine grape vineyards in the state are treated at least three and as many as 10 times annually with fungicides for powdery mildew control. If the disease is insufficiently controlled during the growing season, resulting fruit will be unacceptable for winemaking. Mildew-infected grapes impart an unpleasant odor and flavor to wine; most wineries will reject grape clusters containing more than 5% mildew infected fruit.

Most growers use sulfur or one of the sterol-inhibiting fungicides (fenarimol (Rubigan), myclobutanil (Systhane), triadimefon (Bayleton) or triflumizole (Procure)) to control powdery mildew. Sterol-inhibitors are often tank-mixed or alternated with sulfur. These compounds and sulfur have several drawbacks. Sulfur has a short residual (seven to 14 days depending on formulation and weather conditions), it is not rainfast, and it causes skin irritation in farmworkers. Sterol-inhibitors, because they have a biochemical mode of action, are susceptible to the development of resistance. Powdery mildew resistance to sterol-inhibitors has been documented in some California vineyards since the mid-1980s. Although sulfur and sterol-inhibitors provide sufficient mildew control in most years, weather conditions in 1995 were so conducive to mildew growth that even the most diligent programs failed to control it in some cases.

The Washington Wine Advisory Board and the Northwest Small Fruit Research Center in 1996 funded an effort to screen newly registered and unregistered fungicides for efficacy in controlling powdery mildew. Unregistered fungicides may not be used commercially in the state of Washington. Screened compounds included azoxystrobin (Abound), BAS490F, tebuconazole (Elite), mineral oil (JMS Stylet-Oil), and the parasitic fungus Ampelomyces quisqualis (AQ10). Abound, made by Zeneca Ag Products, and BAS490F, made by BASF, belong to a new class of fungicides called strobilurins. These have a biochemical mode of action different from that of the sterol inhibitors. Elite, manufactured by Bayer, is a sterol inhibitor, so it has a similar mode of action to compounds already used widely on grapes. JMS Stylet-Oil is a food-grade quality mineral oil manufactured by JMS Flower Farms. Its mode of action is unknown, but it is thought to interfere with recognition of the host plant and initiation of feeding. AQ10, which parasitizes U. necator, is manufactured by Ecogen. All the compounds except for JMS Stylet-Oil were alternated at some point during the season with another fungicide, in order to simulate a resistance management program that would be used in a vineyard. Alternated fungicides are indicated by "/" marks in Tables 1 and 2. For example, Elite/sulfur indicates that Elite was alternated with sulfur in that treatment. The new fungicides were compared to an untreated control and to an industry standard treatment of fenarimol (Rubigan) alternated with sulfur.

A Chardonnay vineyard near Grandview, Wash. was the trial site; Chardonnay is a high value grape variety susceptible to powdery mildew. Plots were evaluated throughout the growing season for incidence of mildew infection on leaves and clusters. A final evaluation was conducted at harvest of mildew incidence (number of clusters with mildew divided by the total number of clusters in the plot) and mildew severity (percentage of each cluster infected with mildew).

Disease pressure was very high in plots. BAS490F alternated with Rubigan and BAS490F alternated with sulfur proved most effective at controlling powdery mildew; plots with these treatments had the lowest incidence of mildew on grape clusters (Table 1) and lowest severity of mildew (Table 2) at harvest. Elite alternated with sulfur was also effective, but plots receiving Elite alternated with Abound had significantly greater mildew severity than did plots receiving both BAS490F treatments, Elite/sulfur and JMS Stylet-Oil (2%) (Table 2). Plots receiving the industry standard treatment, Rubigan/sulfur, had significantly higher mildew incidence at harvest than did plots with the BAS490F treatments and significantly greater mildew severity than the plots with the BAS490F treatments, Elite/sulfur, and JMS Stylet-Oil (2%). Both rates of Abound were similar in efficacy to Rubigan/sulfur. AQ10 was ineffective in controlling powdery mildew, possibly due to the organism being killed by hot, dry conditions such as those occurring during the eastern Washington summer.

Table 1. Percent Chardonnay grape clusters infected with powdery mildew at harvest.
BAS490F/Rubigan 75% a*
BAS490F/sulfur 81% ab
Abound (low rate)/Rubigan 87% abc
Elite/sulfur 93% bc
Elite/Abound 93% bc
Abound (high rate)/Rubigan 95% bc
JMS Stylet-Oil (2%) 95% c
JMS Stylet-Oil (1%) 97% c
Rubigan/sulfur 98% c
AQ10 100% c
untreated 100% c
*Means with the same letters are not statistically different.

Table 2. Average percent of each cluster infected with powdery mildew at harvest.
BAS490F/Rubigan 4% a*
BAS490F/sulfur 9% b
Elite/sulfur 10% bc
JMS Stylet-Oil (2%) 14% c
Elite/Abound 21% d
Abound (low rate)/Rubigan 22% d
Rubigan/sulfur 22% d
Abound (high rate)/Rubigan 23% d
JMS Stylet-Oil (1%) 33% e
AQ10 52% f
*Means with the same letters are not statistically different.

Dr. Anne Morrell is a research associate at the Food and Environmental Quality Laboratory working with Dr. Alan Schreiber.

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I prefer Delaney . . .

...Alan Schreiber

As the dust begins to settle in regards to the Food Quality Protection Act of 1996, it is increasingly clear that American food producers will be giving up much and receiving little in return. The first impact of the FQPA is that 12 tolerances about to be issued by EPA were held up. Seven of these were important to the Pacific Northwest. Among the first casualties were leaf lettuce, hops, filberts, snap beans, peppers, grass seed and mint. The second impact was that several Section 18s are on hold. By the end of the year, EPA estimates that 100 applications will be pending. The Section 18 impacts will become even more significant, as existing registrations begin to be canceled under the new, more stringent requirements.

In a review of the act, Jerry Baron, National Coordinator for the IR-4 Project, suggested that a strict interpretation of the FQPA will result in more cancellation of registrations than the entire reregistration process. He concluded that the costs to agriculture are likely to outweigh the incentives for agriculture. I predict that registrations for many pesticides belonging to classes such as organophosphate, carbamate, pyrethroid, triazine and EBDCs are going to be lost.

Certainly, there will be some societal benefits from the act. There is no doubt that there will be less pesticide residues in the food supply. But the value of reducing pesticide residues is not immediately clear. The FDA pesticide residue monitoring program states that 58% to 65% of domestically produced foods do not contain residues; the percent of foods with residues over tolerance is less than 1%, and this has been a consistent trend for years.

I question whether the expected reduction in pesticide residues in food is going to be worth the trade off in disruptions to food production. I am sure these disruptions will go largely unnoticed by the public. Someone will always grow more food. We may be eating different types of food, paying slightly higher prices, or eating more imported food. What most of us will not notice is the grower experiencing reduced yields and increased costs of control or the grower who decides to grow something other than fruits or vegetables.

Who let this happen? Who allowed this to pass? Who supported this legislation? USDA and EPA were instrumental in arranging many of the act's provisions. Are they responsible? A visit to the American Crop Protection Association's home page on August 3, 1996, the day President Clinton signed the act, provides some insight. The ACPA position at the time of signing was, "The American Crop Protection Association joins with food industry, agriculture and environmental organizations to celebrate as President Clinton signs into law the bi-partisan Food Quality Protection Act..."

I wonder if the ACPA, which represents pesticide manufacturers, formulators and distributors, is celebrating now.

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WSU offers pesticide education

The winter training schedule for Washington State University pesticide education programs is completed. Brochures were mailed October 9, 1996 to individuals with a current pesticide license. Both Pre-license and Recertification courses will be offered this winter. A Spanish recertification class will be offered in Pasco in November. A pre-license aquatic session will be offered January 23, 1997. Registration is $40 per day, unless postmarked 14 days prior to the program, in which case it is considered early registration at $30 per day.

In response to comments regarding the Integrated Plant Health Workshop held last season in Puyallup, WSU has scheduled two workshops this year -- one in Spokane and one in Puyallup.

More information regarding winter training or registration may be obtained by contacting Cooperative Extension Conferences at 509-335-2830, the WAPP World Wide Web site at http://www.wsu.edu:8080/~ramsay or email: ramsay@wsu.edu.

Recertification Schedule. Each day provides six recertification credits.

Eastern Washington

Western Washington

Pasco     Nov. 12, 13 Lynnwood     Nov. 19, 20
Pasco (Spanish )    Nov. 13 Fife Jan. 15, 16
Okanogan Nov. 20 Kelso Jan. 28, 29
Moses Lake Jan. 23, 24 Lynnwood Feb. 4, 5
Pasco Jan. 23, 24 Mt. Vernon Feb. 12, 13
Yakima Jan. 27, 28 Bellevue Feb. 18, 19
Spokane Feb. 19, 20 Elma Mar. 4, 5
Pullman Feb. 26, 27

Integrated Plant Health Management Workshop
Puyallup Feb. 24-27 Spokane Mar. 4-7

Pre-License Schedule. The pre-license program offers no recertification credits. Testing is scheduled for Day 3 in the afternoon.

Eastern Washington Western Washington
Moses Lake Jan. 15-17 Fife Jan. 14-16
Pasco Jan. 21-23+aquatic Kelso Jan. 27-29
Yakima Jan. 29-31 Lynnwood Feb. 3-5
Spokane Feb. 18-20 Mt. Vernon Feb. 11-13
Pullman Feb. 25-27 Puyallup Mar. 11-13

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Plastic pesticide container
collection dates, requirements

Container requirements

1. Must be multiple rinsed, so that no residues remain.

2. Must be clean and dry inside and out, with no apparent odor.

3. Hard plastic lids and slip on lids must be removed.

4. Glue-on labels may remain.

5. The majority of the foil seal must be removed from the spout.
A small amount of foil remaining on the container rim is acceptable.

6. Half pint, pint, quart, one and two-and-a-half-gallon containers will
be accepted whole.

7. Five-gallon containers will be accepted whole if the lids and bails
are removed.

8. Special arrangements must be made for 30-gallon and 55-gallon
containers, by calling (509) 457-3850 prior to the collection.

Containers not meeting above specifications will not be accepted.

WPCA container collection dates





9-2 p.m.

Snipes Mtn.

Yakima County
Mark Nedrow

509-574-2457 Cardboard accepted


Terrace Hts.

Yakima County
Mark Nedrow

509-574-2457 Cardboard accepted


Windflow Fert.,

Windflow Fertilizer
Mauri Worgum


For more information about plastic pesticide container collection, contact:

Steve George
WPCA Recycling Coordinator
31 High Valley View St.
Yakima, WA 98901
(509) 457-3850
or the WAPP web site at http://www.wsu.edu:8080/~ramsay/wpca.html

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Federal Issues


The following tolerances were granted by EPA since the last report (September 1996). These data do not mean that a label has been registered for this use. These pesticides must not be used until a label is registered with EPA or a state department of agriculture.

A=adjuvant D=desiccant D/H=desiccant, herbicide F=fungicide
FA=feed additive FM=fumigant G=growth regulator H=herbicide
I=insecticide N=nematicide P=pheromone V=vertebrate repellent

Chemical* Petitioner Tolerance (ppm) Commodity (raw)
(I) Pyridaben EPA exempt apples: processed feed commodity,
wet apple pomace

EPA is witholding final rules revoking 17 processed food tolerances. The agency is withdrawing these revocations because they were based on two provisions of the Federal Food, Drug and Cosmetic Act, specifically the Delaney Clause and the "ready to eat" provision, that no longer are applicable to pesticide residues in food. Since the enactment of the Food Quality Protection Act, the basis for these revocations no longer exists as a matter of law. Accordingly, EPA is withdrawing these final rules:

Pesticide Commodity

Acephate food handling establishments
Benomyl tomato products, raisins

Dichlorvos (DDVP) bagged and packaged processed foods

Dicofol dried tea

Ethylene oxide ground spices
Iprodione dried ginseng, raisins
Mancozeb bran of oats
Propargite dried figs, dried tea
Propylene oxide cocoa, gums, processed nutmeats (except peanuts), processed spices
Triadimefon milled fractions of wheat
Imazilil citrus oil

Emergency Exemptions (Section 18)

Specific exemptions have been granted for the following uses:

Hacco, Inc. for use of zinc phosphide to manage vole (Microtus) complex in timothy and timothy-legume stands produced for hay and timothy produced for seed. The exemption expires April 15, 1997.

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Contributors to the Agrichemical and Environmental News:

Alan Schreiber, Allan Felsot, Catherine Daniels, Mark Antone, Carol Weisskopf, Eric Bechtel

If you would like to include a piece in a future issue of the Agrichemical and Environmental News, please contact Alan Schreiber. To subscribe to the newsletter, please contact Eric Bechtel.

Contributions, comments and subscription inquiries may be directed to: Food and Environmental Quality Laboratory, Washington State University, 100 Sprout Road, Richland, WA 99352-1643, ph: 509-372-7378, fax: 509-372-7460, E-mail: ebechtel@beta.tricity.wsu.edu.

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