UNIVERSITY OF CALIFORNIA
ENVIRONMENTAL TOXICOLOGY NEWSLETTER
Vol. 6 No. 1 February 1986
HAZARDOUS AGRICULTURAL CHEMICALS
IN THE ENVIRONMENT
This newsletter contains two reports developed by the members of the Hazardous Agricultural Chemicals in the Environment (HACE) Task Force. The first is a brief summary of the workgroup reports, and the second is the full context of the HACE workgroup reports. We developed a list of all the participants in the Task Force which is not included in this newsletter. If you would like a copy, please call or write and we will send one to you.
The HACE Task Force was formed by Drs. Lowell Lewis and Jerry Siebert early last summer. Dr. Jim Seiber, Professor, Department of Environmental Toxicology and I were appointed as co-chairpersons of the Task Force. I welcome your input on the HACE reports in this newsletter. If there are any critical areas that we have missed, I would certainly like to know about them. I hope this information is useful to you in the counties.
In July 1985, over fifty University of California scientists gathered in Sacramento to participate in a workshop sponsored by the Division of Agriculture and Natural Resources. The purpose of this workshop was to define research and extension needs in the subject area of pesticides and other hazardous agricultural chemicals. The scientists were principally toxicologists, environmental chemists, engineers, soil scientists and pest control specialists. The agenda was composed of general sessions and breakout workgroups that covered the following special topics:
The scientists that participated were asked to evaluate the status of existing knowledge and research efforts in these four areas, to prioritize statewide research/extension needs, and to recommend specific research/extension programs to address these needs. It was the consensus of all persons involved that pesticides are the chemicals of greatest concern, and this is reflected in the summaries of each workgroup. The findings of each workgroup are summarized below.
1. ENVIRONMENTAL CHEMISTRY
There is an urgent need for more information on the principles and variables that govern the fate of agricultural chemicals in the environment in order to deal more effectively with present contamination problems and to avoid future contamination of groundwater. The environmental behavior of agricultural chemicals is similar to that of other chemicals that threaten to pollute groundwater. Therefore information gathered studying agricultural chemicals will have application in predicting the environmental behavior of other chemicals. The following research/extension needs were identified as high priority areas for future work:
A. Research on chemical transport processes in soil (chemical, physical and biological factors affecting movement and degradation).
B. Research on water borne transport and fate processes (emphasis on groundwater).
C. Research on atmospheric transport and fate processes (physical and chemical factors affecting volatilization, photodegradation, etc.).
D. Preparation of a critical review of existing knowledge and establishment of databases of physicochemical properties and environmental behavior of chemicals.
Because there are numerous variables making each of these areas of study extremely complex, the workgroup recommended initiating laboratory and field studies of a few chemicals and environments representative of California pesticide usage.
The human toxicological concerns surrounding the use of agricultural chemicals include both acute (short-term) exposure and chronic (long-term) exposure. Tremendous progress has been made over the last 15 years in reducing the number of severe poisonings by agricultural chemicals; however, accidental exposures still occur during application and when workers reenter treated fields. Public concern is often focused on the presence of very low levels of pesticide residues in food or groundwater, yet the toxicological significance of these low levels is unknown. Other potentially important toxicological problems relate to crop damage due to drift, bird and fish kills, and accidental contamination of livestock. In order to address these problem areas, the following research/extension needs were identified:
A. Development of better toxicity tests and models to predict both acute and chronic health effects, and better methods for extrapolating the test data to human exposure levels.
B. Determination of the mechanism of toxic action (from the molecular level to ecosystem level) in target and nontarget species.
C. Determination of the chemical composition and toxicological properties of chemical mixtures, metabolites, degradation products and natural toxicants.
D. Development of better chemical and biological methods to monitor low level exposure to agricultural chemicals.
E. Improvement and expansion of programs for training toxicologists and disseminating toxicological information.
3. WASTE DISPOSAL
Pesticide waste disposal was identified as the highest waste disposal priority. There is a critical need for research and extension programs to manage pesticide wastes. The waste disposal task force workgroup unanimously agreed that the best disposal option is complete, on-site detoxification. Relocation of wastes to disposal sites should be viewed as only a temporary solution. The development of safe and effective methods for detoxification of pesticide wastes will require ongoing research in environmental chemistry, and the application of this research to field conditions. The information that would be gained by these research/extension programs would be of enormous immediate value to pesticide applicators, state agencies, and others confronted with the need to decontaminate pesticide wastes. The waste disposal workgroup also identified the following wastes as important to agriculture: fertilizers, animal wastes, food processing wastes, crop residues, domestic sewage and industrial waste. The following research/extension needs were identified:
A. Development of safe, effective, on-site methods to clean up currently existing pesticide disposal sites.
B. Development of safe, effective, on-site methods to detoxify pesticide wastes as a result of cleaning spray equipment.
C. Improvement of methods used for detoxifying pesticide spills and empty containers.
D. Promotion and extension of management programs for fertilizers, animal wastes, food processing wastes, crop residues, domestic sewage and industrial waste.
4. SOURCE MANAGEMENT
Future environmental problems can be minimized by improving methods of handling and using agricultural chemicals. Improvements in this area will require the compilation and comparison of existing information, development of new knowledge and technologies, and extension of programs to make this information available to agricultural chemical users. The workgroup identified the following research/extension efforts for emphasis:
A. Improvement of pesticide application technology to reduce environmental contamination and increase efficacy. Emphasis is needed on engineering to develop methods that: 1) improve pesticide delivery to the target site, 2) decrease the volume and amount of pesticide necessary, and 3) eliminate or reduce the pesticide waste produced by cleaning of application equipment.
B. Development of extension programs encouraging the efficient use of agricultural chemicals. Emphasis is needed on: 1) the development of new pest control methods, 2) improvement of pest control recommendations, 3) implementation of IPM programs, and 4) label improvement.
C. Coordination of database development on the extent of statewide contamination problems. Information gathering and data analysis should be coordinated between state agencies and the University in order to avoid unnecessary and costly duplication of effort.
D. Development of improved packaging, handling and disposal techniques to reduce environmental contamination associated with mixing/loading and equipment cleanup.
California consumes nearly one-quarter of the total quantity of pesticides used in agricultural production in the United States. This is due in part to the size and diversity of the state's agricultural industry. While we recognize the need for a continuing use of pesticides, several problem areas have surfaced and intensified in recent years occasioned by the unique geography and climatology of the state, its rapid urbanization, and the stiffening of regulations (at both the Federal and State levels) governing pesticide use, permissible residue levels in foodstuffs and the environment, and pesticide waste disposal.
The UC Division of Agriculture and Natural Resources (ANR) recently convened a task force on Hazardous Agricultural Chemicals in the Environment (HACE) to consider the problem areas, enumerate the technical and informational needs associated with agricultural chemicals, and recommend research and extension efforts to deal with these needs. The HACE Task Force, composed largely of environmental chemists, toxicologists, engineers, and pest control specialists, recommended an accelerated program of research and extension, including specific focuses on environmental fate studies, toxicological evaluations, source management, and waste disposal. To implement this program, the development of multidisciplinary teams (including collaborators in other units of the UC system) was recommended. These teams would function to evaluate existing knowledge, prioritize potential ANR efforts, and implement specific research/extension programs. The Task Force also recognized the need for a steering committee to provide better coordination of ANR activities related to pesticides and other agricultural chemicals, increased staffing in some critical areas (particularly in Cooperative Extension), and increased budgeting for research. Finally, the Task Force viewed an increased effort in training students and pest-control practitioners, and delivery of information to the public and its agencies, as proceeding hand-in-hand with a large, concerted research effort aimed at improving the state's pesticide safety record.
This report represents the summary findings of the HACE Task Force meeting held on July 9-10, 1985. The primary focus was on pesticides -- their environmental chemistry, toxicology, source management, and waste disposal, although other chemical hazards were considered and are discussed in the report.
I. ENVIRONMENTAL CHEMISTRY
Workgroup Chairs: James Biggar and William Jury
There is an urgent need for a better understanding of the principles governing the behavior of chemicals in the environment, in order to deal more effectively with present contamination problems and, particularly, to avoid contamination in the future. This will involve a concerted effort by environmental, analytical and physical chemists, biochemists, hydrogeologists, soil physicists, atmospheric scientists, and those in related environmental science disciplines.
Statements of needs and research proposals relative to environmental chemistry of pesticides follow.
1. Critical review of existing knowledge.
a. Classification of pesticides found in groundwater with respect to their known properties, and of overlying soil properties and surface practices.
b. Critique of existing database on physical and chemical properties of pesticides.
c. Evaluation of the utility of such properties as indicators of environmental behavior of pesticides.
d. Critique of pesticide environmental transport/fate models.
2. Soil transport and fate.
a. Chemical and biological degradation.
i. Identification of reaction pathways and products.
ii. Determination of rate constants for key reactions.
iii. Determination of concentration dependence of rate constants.
iv. Estimation of soil and environmental effects on rate constants.
b. Transport through soil and water.
i. Estimation of groundwater residence times.
ii. Estimation of unsaturated zone residence times.
iii. Determination of concentration dependence of transport processes.
iv. Study of the influence of colloidal or soluble organic constituents on pesticide transport.
v. Development of improved monitoring and waste extraction methods.
vi. Field validation of transport and fate models.
3. Atmospheric transport and fate.
a. Estimation of volatilization inputs from agricultural fields.
b. Estimation of atmospheric reaction pathways, rate constants and lifetimes.
c. Development of atmospheric transport models.
d. Assessment of acute and chronic exposure to airborne pesticides.
e. Determination of high temperature reaction chemistry, such as occurs during intentional or accidental combustion.
f. Recommendations for atmospheric monitoring.
4. Development of management guidelines for pesticide use in agriculture.
a. Determination of management practices which minimize pollution.
b. Development of registration criteria to aid in identifying undesirable chemical characteristics.
a. Improved estimates of bioconcentration factors.
1. Critical evaluation of pesticides in California groundwater.
An intercampus task force, working with staff support, will relate pesticide concentrations in groundwater to their physical- chemical properties, to overlying soil properties and to sources at the surface. From this study will emerge a contamination map and a first cut at cause-effect relationships as well as a set of recommendations for further research on minimizing or preventing contamination.
2. Field scale mass balance studies.
A technical workshop will be held to design a comprehensive, multi-chemical field study whose purpose will be to monitor chemical fate pathways (volatilization, leaching, degradation, runoff, etc.) after application to soil. From this study will emerge a comprehensive data set for model calibration and validation, an assessment of atmospheric loading of pesticides above agricultural fields, and of persistence and leaching under field conditions. The relevance of laboratory-measured properties to estimating fate pathways observed in the field can also be examined. This project should be duplicated on several soil types.
3. Critical evaluation of priorities in reaction pathway research.
An intercampus task force will evaluate the existing literature on pesticide chemical and biological reaction pathways, rates and reaction products. This exercise will produce a database which can be critically reviewed and used to identify information gaps and priority areas for research. Strategies may emerge for classifying compounds into groups for detailed study and for picking key compounds for subsequent experimentation. Finally, the committee should work towards identifying the rate-limiting step in a reaction chain and the corresponding persistent products. Specific research projects in this subject matter area will be developed based upon the evaluation.
4. Measurement of degradation rates in root zone, sub-surface soil profile and in groundwater.
Several pesticides which have been observed in groundwater will have their degradation reactions studied in samples taken from the surface soil, biologically active top meter of soil, the subsurface vadose zone and in groundwater. Associated measurements of organic carbon, microbial activity, etc. will be made on subsamples.
5. Effect of pesticide concentration on degradation and adsorption reactions.
Pesticide waste disposal, among other activities, has resulted in the presence of compounds in soil at concentrations higher than those for which experimental information is available. In addition, increases in analytical detection have revealed low concentrations of compounds as bound residues in soil and biota. Research is needed to extend experimental information to both high and low concentration situations to determine degradation rates and adsorption dependence on pesticide concentration.
6. Development of monitoring procedures to identify soil, aquatic and atmospheric components of commercially applied pesticides.
A committee of university experts, in cooperation with state agencies, will design a comprehensive sampling program whose purpose will be to assess the extent of soil, aquatic (groundwater, drainage water) and atmospheric residues associated with pesticide applications. This program will result in an estimate of pesticide travel times in unsaturated soil, degradation efficiency, bioconcentration factors, groundwater/drainage water concentration, and atmospheric exposure to pesticides. A recommendation for routine monitoring of certain pathways should emerge from this study as well.
7. Assessment of atmospheric reaction pathways and lifetimes.
As a result of the monitoring survey discussed above, certain key pesticide compounds will be chosen for fundamental environmental chamber studies of reaction pathways, reaction rate coefficients and atmospheric lifetimes.
This subcommittee deliberately stressed the role of committees and task forces in designing research projects and evaluating existing information. The committee review and assessment is essential because of the interdisciplinary nature of the research and because literature information is widely scattered and of variable quality. The Division of Agriculture and Natural Resources is an appropriate organizational framework within which to conduct the multidisciplinary committee work.
The committees will recommend specific research projects for implementation. No individual should be expected to carry out the time-consuming committee/task force activity outlined above unless the follow-up funding for research is available. Thus, both committee funds and a reasonable research budget for a given project should be procured prior to commencing committee activity.
Workgroup Chairs: John Casida and Roy Fukuto
Toxicological research is a continuing process and it is difficult to separate out short-term from long-term needs. University toxicologists may respond to emergency or crisis situations attributable to hazards arising from the use of agricultural chemicals; however, the nature of toxicological research requires a long-term effort. Data developed from such research allows personnel in the Division of Agriculture and Natural Resources to provide advice, information, and recommendations for action in such crisis situations as:
1. Accidental poisoning during application, reentry, or inadvertent exposure to toxic substances.
2. Fish kills following pesticide use.
3. Crop damages attributable to drift of herbicides to nontarget areas.
4. Contamination of livestock species with persistent compounds.
5. Human exposure to known mutagens or carcinogens.
6. Drinking water contamination with low levels of chemicals.
As the use of pesticides and related chemicals in agricultural production and the protection of public health continues, toxicological problems -- whether real or perceived -- arising from the use of these materials will likely increase in the foreseeable future. In order to respond to these problems, the Division of Agriculture and Natural Resources must increase its activities in toxicological research and education.
Toxicology research and education is needed to improve the long-term record of safe use and to deal with crisis situations. Specific needs include:
1. Determine the nature and composition of:
a. Pesticide chemicals (old, current and new).
b. Impurities and degradation products.
d. Carriers and inert chemicals.
e. Other agrichemicals.
f. Natural toxicants.
2. Determine the mechanisms of action (molecular to ecosystems) underlying:
a. Nontarget vs target species susceptibility.
b. Selective toxicities.
c. Reversible vs irreversible actions.
3. Identify and exploit new strategies for pest control, including new chemical and biological agents, and new molecular targets.
4. Develop toxicity tests and toxicity data relating to:
a. Acute and chronic effects.
b. Alternate or short-term tests, emphasizing such end points as immunology and behavior.
c. In vitro tests using tissues, cell and molecular systems.
d. Interactions among chemicals including use of antidotes, reduction of body burden, and synergism and potentiation.
e. Methods of extrapolating from in vitro to in vivo, from laboratory to man, and from residue levels in environmental samples to human health effects.
5. Develop chemical and biological monitoring methods (including rapid assays for field use) to study:
a. Human exposure.
b. Ecological effects.
c. Effects on veterinary and domestic animals.
6. Improve and expand programs for training toxicologists, and disseminating toxicological information through:
a. Graduate programs.
b. Cooperative Extension programs.
c. University Extension programs.
1. Nature and composition of the applied agents.
The applied agents (pesticides, fertilizers, etc.) are frequently not pure substances but rather mixtures containing impurities from the manufacturing process and degradation products formed before and after application. These agents are further modified in the environment by the action of light and the atmosphere, and by metabolism by soil microorganisms, plants and animals. Carriers and "inert" chemicals are normally added to the active ingredient, while naturally-occurring toxicants may be present in the target application zone. The identification, characterization and toxicological evaluation of all such substances are essential to the assessment of hazard. Priorities for immediate attention will be developed by a committee of experts considering the amount and pattern of use in California, and the potential of specific formulations to contain hazardous ingredients.
2. Mechanism of action of pesticides from molecular to ecosystem levels.
Fundamental studies must be carried out on the mechanism of action of different pesticides in order to determine the underlying bases for their toxicity in target and nontarget species. The information accrued, e.g., differences in target site sensitivity, rates and routes of metabolism, etc., is needed for the design of new compounds which are selectively toxic to the target organism and safe to beneficial organisms. The effects of pesticides, and whether or not they are reversible, must be studied not only on target species but also on the ecosystem as a whole. Considering limitations in time and resources, a few chemicals should be studied in depth focusing on those having unknown or novel modes of action. The selection of chemicals for attention will, once again, be assigned to a committee of experts.
3. Development of new types of selective toxicants lacking adverse effects on man and his ecosystem.
This area is critical to maintaining agricultural profitability and the low cost of food and fiber in our society. A key role for the university is in the discovery and exploitation of new molecular or cellular targets for the control of pest, plant and animal species. This work must proceed by an integration of classical and modern biotechnology, and must include development of methods for evaluating the toxic risk posed by these new materials. It will involve collaboration with biologists, chemists, and toxicologists both in the University and in the pesticide industry. An early task will be to establish teams of appropriate experts able to assess and recommend new targets for pest control.
4. Development and mechanistic studies of short-term assays for evaluating risks.
This information is necessary in order to better understand currently used agents and to develop new pest management strategies. As animal assays are costly and not always readily available, new protocols should be sought utilizing model systems and in vitro tissue, cellular and molecular techniques. These protocols should attempt to evaluate more complex toxicological effects including immunological and behavioral changes, and interactions between compounds. Methodology, both experimental and mathematical, is also required to enable the extrapolation of experimental data to man, and evaluation of the toxicological significance of residues to man. Increased research is also needed to develop antidotes to pesticides, particularly for those agents possessing high inherent toxicity and those used in large-scale pest control programs.
5. Development of improved monitoring processes to help establish the movement and fate of agricultural chemicals in the environment.
New analytical techniques are needed for measuring kinetics and pathways of agricultural chemicals in ecosystems, and to establish human and animal exposures. Examples for immediate attention are immunoassays, bioassays, and simple chemical tests which can be used for rapid analysis in the field.
6. Improving the capabilities of Cooperative Extension to train public and industry personnel in the safe use of chemicals.
a. There is only one extension toxicology specialist in California. There is an urgent need for the appointment of several additional extension toxicology specialists to address human, veterinary and environmental toxicology issues. These specialists should be housed on multiple UC campuses.
b. Cooperative Extension, University Extension and formal university courses should be expanded to increase opportunities for education of manufacturers, formulators, applicators, emergency personnel, state officials, the news media and the public.
c. There is a need for development of new methods of toxicological information dissemination to the public. Traditional methods of information dissemination (leaflets, fact sheets, etc.) also need to be continued and improved.
7. Enhancement of graduate training programs.
UC Berkeley, UC Davis and UC Riverside all have training efforts in toxicology, yet each needs to be enhanced. For example, there is no interdisciplinary program for graduate training in toxicology at UC Riverside although there are many excellent toxicologists on the campus. UC Davis has a long-standing Pharmacology-Toxicology graduate program that is currently undergoing program revision to meet the diverse needs of modern pharmacology-toxicology research. No single training program presently encompasses ecological, plant, animal, clinical, cellular and molecular toxicology. Current training programs need to be reevaluated and improved, and new programs initiated.
8. Consideration of establishment of a University-wide Toxicology Center for coordination of research, dissemination of information and education of the public.
9. Promote improved communications between toxicologists familiar with agriculture and agricultural chemicals with experts in the new UC Toxic Substances Program, Occupational Health Center, and the Schools of Medicine and Veterinary Medicine. This coordination should occur at the campus level, and may involve establishment of campus-based centers or programs in which agricultural, biological, physical, and medical scientists interested in the broad aspects of "toxics" freely participate.
III. WASTE DISPOSAL
Workgroup Chairs: Art Craigmill and Wray Winterlin
The task force workgroup on pesticide waste disposal recognizes that the best disposal alternative is to work on complete detoxification procedures. Relocation of wastes to "secure" disposal sites is only a temporary solution to the waste problem. Environmental chemistry research on the mechanisms of transport and degradation of pesticides is essential to the management of pesticide wastes; such research should be applied to development of on-site decontamination and neutralization of pesticide wastes.
1. Pesticide waste disposal (detoxification).
a. This is a critical need due to recent strict regulations governing waste treatment and disposal. Current technology is either not adequate or too expensive to allow pest control operators to comply with current regulations. Methods are needed to assess, characterize, and dispose of pesticide wastes in the form of:
i. Concentrated spills.
ii. Dilute pesticide solutions (rinsewaters).
iv. Existing contaminated and disposal sites.
b. Extension programs are needed in this area, including:
i. Field research and demonstration trials to develop and disseminate appropriate technologies.
ii. Programs dealing with both rural and urban (household) pesticide disposal.
2. Domestic sewage and industrial waste.
a. The nature of sewage sludges used as agricultural amendments is well known; however, information and education programs dealing with the safe use of such materials as amendments need to be developed for dissemination to growers.
b. Guidelines for the use of industrial wastes on agricultural land need to be developed in order to prevent toxicity problems. As the promotion of industrial wastes for use as agricultural amendments continues, guidelines must be developed for determining if these pose a toxicity hazard.
c. The urban disposal of pesticide wastes and other chemical wastes represents a source of harmful chemicals to the sewage system. The effects of these chemicals on subsequent use of sludge needs to be investigated and evaluated.
3. Fertilizers and animal wastes.
Mechanisms for preventing nitrate contamination are known, but programs need to be developed for their implementation. The adoption of currently available management procedures by producers is needed to promote effective use of these fertilizers and to prevent local contamination problems.
4. Food processing wastes and crop residues.
The potential presence of hazardous chemicals in these types of agricultural wastes must be recognized. Research and extension needs in these areas -- while not presently critical -- may develop in the future.
1. Pesticide waste disposal.
a. Further development of more accurate, rapid, sensitive, and inexpensive analytical methods for use in waste site evaluation, including assays for degradation products and metabolites.
b. Development of characterization technologies for contaminated disposal sites.
c. Development of new and innovative technologies for disposal systems tailored to the needs of both small and large generators of pesticide wastes, emphasizing on-site disposal.
d. Laboratory and field research on the application of detoxification processes, including biotechnological methods, to existing waste disposal sites.
e. Predictive modeling of pesticide transport and breakdown in soils, including the interactions between chemicals in gross mixtures.
f. Management modeling to aid in the evaluation and mitigation of hazards at pesticide disposal sites.
g. Database development of information gathered from site assessment projects statewide for use in predictive and management modeling research.
h. Assessment and comparison of waste management options, along with associated economic, environmental and health considerations.
2. Disposal of wastes associated with sewage treatment, industry, fertilizers, animal excreta, food processing, and crop residues.
Specific research proposals involving several of these types of wastes (particularly sewage, fertilizer, and animal wastes) should be developed in consultation with experts involved in the selenium/salinity task force of the UC Division of Agriculture and Natural Resources.
IV. SOURCE MANAGEMENT
Workgroup Chairs: Robert Brazelton and Harry Shorey
Improving the ways in which we handle and use agricultural chemicals offers excellent possibilities for minimizing environmental contamination in the future. Such improvements will require a better collation of existing information, development of new knowledge through research, and improving the process for making this knowledge available to those who work with the chemicals.
1. Establishment of databases on the extent of the contamination problem in:
a. Urban, forest and various agricultural environments, delineating the extent of the problem attributable to specific pesticides and their adjuvants, to fertilizers, and to agricultural wastes from animals, food processing, crop residues and sewage sludge.
b. Stages of chemical handling, including spillage during loading, the actual application, rinsing and cleaning of equipment, and disposal of containers.
2. More efficient use of pesticides in pest management programs. This includes a need to evaluate:
a. Procedures for making pest control recommendations.
b. Label improvement and standardization.
c. Development of alternative pest control methods.
3. Improved pesticide application technology to reduce environmental contamination and increase efficiency of control.
4. Improved packaging, handling and disposal techniques to reduce environmental contamination.
5. Improved utilization of nitrogen and other fertilizers to reduce environmental contamination.
6. Improved management and utilization of animal, food- processing, and crop wastes and sewage sludge.
1. Database evaluation and development.
a. Evaluation of existing resources.
Source management of agricultural chemicals can be improved through informed use, which requires that adequate databases be available to both users and researchers. A number of databases exist in California including:
i. Pesticide registration database (CDFA).
ii. Human illness database (CDFA).
iii. California pesticide use reports (CDFA).
iv. Pest management guidelines database (UC).
Effective use of the information in these databases depends on our having an adequate information distribution system. Traditional publications, such as leaflets, manuals and films, are available in the Division of Agricultural and Natural Resources. A few electronic systems for information distribution are being developed, including the UC IPM Network and UC CE county office computers. Coordination and evaluation of these efforts should be conducted by a Division-wide committee of experts in order to prevent redundancies, provide maximum utilization of existing resources, and recommend alternates where appropriate.
b. Development of new systems.
Additional communications systems will be required to effectively distribute research and developmental results to growers and urban users of agricultural chemicals. We urge support of research on and development and implementation of the UC ANR pest management guidelines database. Further, additional resources should be made available for developing decision- making (expert) systems that will include pest and host models, models to predict spray trajectories, efficacy and drift, weather data, pesticide toxicology, integrated pest management information, and UC ANR pest management guidelines or recommendations.
2. Integrated pest management.
IPM has been developed through UC research/extension programs. These programs have led to better understanding of pest/host relationships and development of more efficient sampling/survey methods and treatment thresholds. Employment of such information has more accurately identified the need for pesticides and led to more efficient pesticide use.
The work on IPM systems should be continued and expanded with the goal of further development of alternative control measures to supplement conventional pesticides. Such alternative methods include:
a. Resistant plant varieties.
b. Cultural practices.
c. Growth regulators.
d. Biological agents (bacteria, viruses, nematodes, etc.).
Acceptance of IPM at this time is limited more by a lack of implementation than by a lack of a research base. There is a serious need for more timely, up-to-date information on IPM and pesticide alternatives on specific crops, and for implementing their adoption by growers. This need should be addressed by committees of experts who can identify data gaps, address regulatory constraints, and promote the university-industry- agency interactions required for IPM implementation.
Information delivery systems should be improved and upgraded to include up-to-date recommendation information to accompany IPM manuals. This information can be utilized as a forerunner to the development of the expert system.
3. Improve application technology.
a. Short-term -- Literature search and correspondence with other states, universities and industry should be conducted in a comprehensive way to determine the "state-of-the-art" in application technology.
i. Develop spray boom injection systems. This will reduce rinse water generation by elimination of the need to introduce technical material into the main spray tank.
ii. Investigate new application technology with particular attention to increasing application efficiency and minimizing drift.
iii. Study the use of pesticides at lower than recommended rates.
iv. Investigate drip application of chemicals in irrigation water.
v. Develop computer controlled application systems.
c. Extension efforts.
i. Improve efficiency of application through workshops dealing with calibration, equipment selection, material calculation and maintenance.
ii. Develop better educational materials and methods, revise existing publications, explore new educational formats.
4. Improve packaging, handling and destruction methods.
a. Short-term -- Study the design and format of labels to prevent misuse.
i. Conduct a feasibility study of container reuse and recycling.
ii. Conduct a feasibility study of container standardization.
iii. Development of systems for direct useage from commercial containers.
c. Extension activities.
i. Survey existing container disposal methods.
ii. Initiate education programs to encourage proper handling.
5. Management/utilization of fertilization and agricultural wastes.
Increase research and extension efforts by the University of California and cooperating growers, industries, and state agencies into the development of methodologies to improve the utilization of nitrogen, other fertilizers, and crop wastes in agriculture.
Arthur L. Craigmill