Environmental Issues: Health

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FINDINGS

The farmers profiled in this report differ from one another in many respects. They produce distinctly different commodities ranging from perennial fruit and nut crops to annual field and row crops to mixed vegetables and dairy. Their climate and soil conditions vary from the arid and windswept high plains of Montana to the humid bayous of Louisiana. Whereas in some areas the growing season is limited by long and harsh winters, in other regions, such as Florida, it lasts all year. The availability of water to their farms ranges from the desert-like conditions of California, where farmers rely extensively on irrigation, to the Mississippi Delta, where water is generally plentiful and in some cases exists in excess of farmers' needs.

Some farmers, including corn and soybean farmers, produce their crops primarily for consumption by livestock. Others, such as apple and tomato farmers, sell their products on the fresh market. Others harvest crops, such as tart cherries, citrus, and raspberries, for canning and processing. While some of the farmers utilize a relatively small amount of acreage and have few, if any, staff, others operate larger farms with a number of employees. Their pest problems vary dramatically depending on the crop and region. Weed control is a predominant concern for Midwestern grain and row crop farmers, while insects and diseases are of greater concern for coastal fruit and vegetable and southeastern row crop producers.

However, when it comes to pest management and the experience of reducing pesticide use, these farmers have much in common. At one time within the past five to fifteen years, they all relied extensively on pesticides to manage insects, weeds, and diseases. In many cases, pesticides were applied prophylactically or on a calendar basis without regard to the level of pest pressure or the presence of natural controls. In response to economic, environmental, health and/or ethical concerns, each of these farmers decided to experiment with alternative agricultural practices. In time, many of them began to view farming as the management of a biological process, not simply the management of inputs to achieve maximum output. And they began to think about their management choices in the context of multi-year cycles in addition to year-to-year profits.

With experience, they have each developed localized, economically viable pest and farm management methods that have led to substantial reductions in the applied volume of synthetic pesticide use,[1] ranging from 10 to 100 percent, depending on the crop and type of pesticide (see Table 2). In most cases, reductions have not been achieved in all of their crops, on all of their acreage, or across all pesticide types (e.g., insecticides, fungicides, and herbicides). However, close to two-thirds of the farmers reduced one or more synthetic pesticide types between 50 and 100 percent.

These farmers' stories provide important insights for formulating policies and programs that encourage reductions in pesticide use and reliance. Much can be learned from their motivations for trying alternative approaches, the on-farm methods and strategies that are effective in reducing pesticide use and managing pests, the barriers the farmers continue to face in their attempt to further reduce pesticide use, and the people and programs that have assisted them in their endeavors. The following section summarizes some of their shared experiences and constitutes this report's major findings.



Economic and Environmental Concerns Are Key Motivations for Change

Changing pest and farming practices is not easy. Farmers who decide to experiment with alternatives assume the risk that a new method may be ineffective and that crop yields or quality may suffer. Assuming this risk requires a high degree of motivation. Farmers in this report were largely motivated to reduce pesticide use by economic, environmental, and health concerns. Some of these concerns are described below.


Insect Resistance and Secondary Pest Outbreaks

A substantial number of insect, weed, and disease species, through basic evolutionary processes, have become resistant to the effects of pesticides. In response to this phenomenon, a number of farmers found themselves needing to apply pesticides with greater frequency in order to achieve the desired level of control. In addition, routine use of broad-spectrum insecticides that destroy target pests created secondary pest outbreaks by killing the natural enemies of non-target insects. For example, some fruit farmers found that certain insecticides that were commonly used for worm control destroy the natural enemies of mitesóan insect that would otherwise not be considered a pest. Once the mites' predators and parasites had been destroyed, these farmers have little choice but to apply additional insecticides to kill out-of-control mite populations.

Resistance and secondary pest outbreaks were particular problems for fruit and vegetable farmers, where historical use of broad-spectrum organophosphate insecticides was particularly high. As a result, farmers applied an increasing amount of one or more pesticides, with diminishing returns. (See the box below, "Pesticides Are Not a Lasting Solution," for a more in-depth discussion of pest resistance and secondary pest outbreaks.)

Pest resistance and secondary pest outbreaks made a number of farmers realize they were running out of effective and reliable pest control tools. These farmers were inclined to adopt alternative strategies regardless of whether or not the costs exceeded those of synthetic pesticides. In general, they believed that over the long run, the costs associated with a continuing cascade of new resistant pests and secondary pest problems would likely be more expensive than switching to alternative, biologically based methods that are less likely to suffer these drawbacks.


PESTICIDES ARE NOT A LASTING SOLUTION

Whereas the capacity of pesticides to harm human health and wildlife species is widely recognized, their potential to cause negative on-farm impacts is less well known. Some of these effects are well summarized by the National Research Council in their recent report, Ecologically Based Pest Management: New Solutions for a New Century,

The disruption of inherent natural and biological processes of pest management, the resistance to pesticides developed by many major pests, and the frequency of pesticide-induced or exacerbated pest problems suggests that dependence on pesticides as the dominant means of controlling pests is not a durable solution.[2]

For example, certain insecticides can disrupt natural biological processes enough to actually create pest problems. Many insecticides are broad-spectrum agents, which means they can kill more than just the target organism. In some situations, broad-spectrum insecticides destroy natural enemies of insects that were previously not pests because they were controlled biologically by their natural enemies. This phenomenon is known as a secondary pest outbreak. In addition to insects, some diseases, normally suppressed by antagonistic pathogens, have become a problem when biological control mechanisms are thrown off balance by the use of broad-spectrum fungicides.[3]

Increasing evidence suggests that, in addition to causing biological disruption, pesticides no longer work as well as they once did. Numerous insects, weeds, and diseases have now developed a resistance to the effects of many pesticides. Insect resistance to synthetic insecticides was first discovered in the 1940s, and as insecticide use became widespread, the problem grew worse. Insects, weeds, and diseases all have the capacity to develop different mechanisms to resist the effects of pesticides and then to select for these mechanisms during reproduction. Over 500 species of insects and mites and close to 200 different species of plant pathogens and weeds are now resistant to one and sometimes several classes of synthetic pesticides.[4] In order to achieve adequate control of resistant pests, farmers usually spray more often, which then exacerbates resistance problems. It is estimated that 10 percent of pesticide use in the United States is applied to combat increased resistance to various pest species.[5]

Pesticides also have the potential to damage important organisms in the soil. Research has shown that less than one percent of the pesticides that are applied to crops actually reach their target organism. The remainder can often, therefore, end up in soil.[6] Although this problem has not been widely researched, it is known that pesticides have the capacity to destroy beneficial macro- and microorganisms in the soil, including earthworms, fungi, and bacteria.[7] Soil organisms are vital to the proper functioning of agricultural systems. Most importantly, earthworms and soil microorganisms break down organic matter and make nitrogen and other nutrients accessible to plants. Some earthworm species are particularly vulnerable to the toxic effects of pesticides.[8]


Environmental and Health Impacts of Pest Management and Agricultural Practices

A number of farmers in this report were motivated to adopt alternative pest and farm management approaches because of concerns about the health and environmental effects of pesticides. Recalls California walnut grower Craig McNamara,

I felt like there were a lot of contradictions in my day to day life. On the one hand, I was farming as a way of creating a lifestyle conducive to family life. And on the other hand, I was using chemicals that might endanger the health of my family. I tried to keep the equipment far away but it never seemed far enough.

And California wine grape grower John Ledbetter says it this way,

Farmers are consumers, too. We get our food from the same supermarkets everyone else does. We drink the same water and breathe the same air. We have children and we can read. That's all it takes to make me want to look for alternatives to pesticides.

Water quality was of particular concern to these farmers. A few farmers realized that by using high amounts of synthetic nitrogen fertilizers and certain herbicides, they were contributing to ground and surface water contamination. This contamination not only affected the quality of their own drinking water, but that of their neighbors.

A number of farmers were also concerned about the impact of conventional farming practices on soil quality. In some regions, farmers grew frustrated with standard crop production practices that leave fields bare during some parts of the year, thereby contributing to water and wind-induced soil erosion. Frequent and deep cultivation of soil to control weeds also leaves fields vulnerable to the erosive effects of wind and water. Erosion usually results in the loss of topsoil which, because of its high nutrient content, is critical for crop production. Some farmers also realized that the productivity of their soil had diminished because they were not building soil organic matter. (See the box on soil quality below for a more in-depth description.) As Francis Otto, a Michigan-based independent pest control consultant puts it,

Everything we do as farmers is related to soil quality. We've already experienced 40 years of soil degradation, and it's time now to give back.


SOIL QUALITY

The Soil Science Society of America defines soil quality as:

. . .the capacity of the soil to function within ecosystem boundaries to sustain biological productivity, maintain environmental quality, and promote plant and animal health. [9]

Loss of soil quality has become an important concern both from an agricultural and environmental perspective. According to the National Research Council:

Soils are living systems that are vital for producing food and fiber for human needs and for maintaining the ecosystems on which all life ultimately depends. Soil directly and indirectly affects agricultural productivity, water quality, and the global climate through its function as a medium for plant growth, a regulator and partitioner of water flow, and an environmental buffer. [10]

A number of agricultural practices can degrade soil quality. For example, leaving fields unprotected and utilizing mechanical tillage methods that disturb the soil at significant depths contribute to soil erosion. Certain forms of erosion have been found to cause soil degradation on roughly 25 percent of U.S. croplands.11 Some agricultural practices also lead to a loss of organic matter content in soil, which can degrade soil structure, water-holding and nutrient-holding capacities, as well as biological activity.

Proper and regular additions of organic materials, mainly through the use of crop rotations, cover crops, crop residues, animal manures, and composts, are the best means of improving and restoring soil quality. Addition of organic matter to soil supports soil microorganisms and invertebrates, which play a vital role in decomposition of organic matter and nutrient cycling. Organic matter helps to improve the physical condition of the soils or tilth, which in turn helps with the transport of water and nutrients in soils. Ultimately, organic matter helps prevent soil.


Increasing Efficiency, Profits, and Flexibility

Most of the farmers were motivated to experiment with alternative strategies by a desire to improve the economic performance of their farming operations. For some farmers, improving economic performance was about being able to compete in worldwide markets in which foreign competitors often have lower production costs, particularly for labor. Other farmers believed they would go out of business if they did not improve economic efficiency. As Wendall Jack, Arkansas rice farmer, puts it,

There are two givens in agriculture. Your production costs always go up, and at best, the prices you get stay the same.

Economic performance can be improved by increasing yields and/or lowering production costs. Most of these farmers focused on reducing production costs. As Wayne Fussel, Georgia cotton and peanut farmer, notes,

We maintain yields in this [alternative] system that are very similar to conventional yields_but yield increases are not what this system is all about, it's about cutting costs.

And Floyd Dahlman, Montana wheat farmer, states,

I wouldn't be in business today if I hadn't found a way to document and accomplish my goal of curbing production costs.

In a number of situations, farmers focused directly on reducing pesticide-related costs, such as through improving pesticide application efficiency to reduce use. In other cases, farmers cut down on overall production costs by adopting entirely new systems of management, such as switching from conventional dairy production to intensive rotational grazing. In these cases, reductions in pesticide use were often an added benefit for farmers but not the over-riding reason for change. A number of organic growers increased profits by decreasing overall production costs and/or receiving premiums in the marketplace for their product. Regardless of how economic performance was improved, it was always directly or indirectly associated with reductions in pesticide use.

A few farmers were motivated to adopt alternative management systems at least in part because they provide greater flexibility in adapting to changes in weather and/or market prices. This was particularly true for alternative systems that rely on utilizing a variety of crops in rotation with one another. For example, one farmer found that having the option of growing a number of different crops enabled him to alter his planting schedule to avoid having to plant during particularly wet periods.



'Starting Small' Helps Smooth Transition Period

Switching from a chemically oriented pest management program to one that is biologically oriented involves taking risks and being patient. When chemicals are reduced or eliminated from an agricultural system, it takes time for natural enemy populations to build up to adequate and effective levels. It takes even longer for soil quality improvements to begin to take effect. In addition, it may take a number of years to acquire the knowledge and management skills necessary for managing more diversified operations. During this "transition," there is the potential for yields to decline, quality to be impaired, and/or costs to rise.

Most of these farmers successfully made the transition to alternative systems of management by starting on a small scale and slowly expanding the amount they managed under the new system. As Wisconsin potato farmer John Wallendal recalls in speaking of his family farm,

At first it took us awhile to get over our fear of making changes on the farm, but it turned out not to be as difficult as we thought it would be. We still don't make changes too quickly because it's risky_but we continually refine our strategies depending on the amount of risk we feel is acceptable in relation to the environmental benefits.

Some farmers also have chosen to tackle one pest problem or pest complex at a time. Fruit growers, for example, who are particularly concerned about pest resistance and secondary pest outbreaks, have focused primarily on enhancing biological control of insect pests and reducing broad-spectrum insecticide use.



Innovative Farmers Utilize A Wide Variety of Alternative Pest and Farm Management Practices

In their search for ways to deal with environmental and economic problems, these innovative farmers have adopted a wide variety of on-farm practices and management systems, including those that can be described as Integrated Pest Management (IPM), sustainable agriculture, and organic agriculture. Despite their distinct definitions, IPM, sustainable agriculture, and organic agriculture share many of the same guiding principles. These principles are well described by the National Research Council's 1989 report on alternative agriculture and include:

  • taking advantage of and enhancing biological relationships on the farm,
  • utilizing management skills and information to reduce costs, improve efficiency, and maintain production, and
  • diversifying cropping systems and farming operations to provide flexibility and stability in coping with environmental and economic hardships.[13]

For the purposes of this report, we refer to IPM, sustainable, and organic farming practices and systems as "alternative." Even though each farmer has developed unique pest and farm management methods, they have all been guided by many of the same principles. The following discussion summarizes some of the alternative pest and farm management practices most commonly used by farmers profiled in this report.


Rotating Crops and Planting Cover Crops

In order to reduce pesticide use successfully, most of the farmers have developed management strategies that maximize the use of on-farm biological relationships. In annual crops, for example, when one or two crops are continuously grown on the same parcel of land, as is the case in a number of conventional production systems, certain pests that feed on these crops flourish because they have a constant source of food. This type of monocropping system often leads to substantial reliance on one or more pesticides. Farmers interested in reducing pesticide applications often rotate a variety of crops in order to deprive pests of a food source and thus prevent the establishment of a destructive level of pests. Depending on the type of crop and cultural practices used in rotation, yields are often improved due to increases in soil organic matter content and availability of plant nutrients.

Enhancing biological mechanisms of pest control is a critical endeavor for farmers interested in reducing insecticide use. Biological control of pests is achieved by: 1) introducing a predator or parasite (also called natural enemies or beneficial species), 2) conserving natural enemy populations that already exist in fields and orchards, and 3) augmenting natural enemies by releasing artificially reared populations. In conventional production systems, in which broad-spectrum insecticides are frequently used, natural enemy populations are often absent or diminished because they lack food and shelter and/or are destroyed by insecticides that do not distinguish between pests and natural enemies. These farmers are able to enhance natural enemy populations by reducing, and in many cases eliminating, their use of broad-spectrum insecticides. Broad-spectrum insecticides are often replaced with biologically based compounds that target specific pests. The farmers also plant cover crops to provide a food source for natural enemies. Cover crops are legume or grass crops planted in the fall or winter between two annual crops or in conjunction with perennial crops between tree and vine rows. Some cover crop varieties have nectar on the undersides of their leaves that provide a food source for beneficial insects. By planting cover crops and enhancing natural enemy populations, these farmers are able to reduce insecticide use substantially. As Washington apple grower, Doyle Fleming, states,

Whenever possible, I want to be farming good bugs as much as I farm fruit.

Cover crops also help with soil fertility management. Leguminous (i.e., plants that bear pods such as peas or beans) cover crop varieties are able to transform atmospheric nitrogen into a form of nitrogen in the soil that provides successive crops with this key nutrient. Farmers have found that planting cover crops allows for reductions in nitrogen fertilizer use.

Moreover, cover crops also compete with and suppress weed growth, thereby allowing reductions in herbicide use. By covering the soil during the winter months, cover crops also reduce erosion from wind and water and help retain moisture in the soil. In the case of one peanut farmer, planting a cover crop helped reduce fungicide use by reducing wind erosion enough to protect young plants from sand-blasting, which weakens the natural waxy coating on the outside of the leaves and makes the plant more vulnerable to diseases. ((See box below.)


COVER CROP USE IN U.S. AGRICULTURE

Healthy soil is the cornerstone of sustainable farming systems. Fertile, productive soils have numerous benefits, not the least of which is providing crops with nutrients that are essential to crop production. Soil organic matter (organic substances in various stages of decay) is crucial to managing soil fertility and productivity. Organic matter is provided by the incorporation of crop residues, application of organic fertilizers such as manures and compost, and by planting cover crops. [14]

Cover crops have numerous potential advantages in addition to supplying organic matter. They can improve soil structure, water penetration and infiltration, and also protect soil from water and wind erosion. They can reduce reliance on herbicides and insecticides by suppressing weed growth and attracting and sustaining beneficial insects, spiders, and mites. The need for synthetic nitrogen fertilizers can be minimized and may be eliminated with leguminous or "green manure" crops, which provide a source of nitrogen for succeeding crops. [15]

The extent of cover crop use in agricultural systems is an important indicator of the movement toward agricultural sustainability. To learn more about cover crop use, NRDC initiated a survey of agricultural seed and supply companies that sold cover crop seed to determine 1) motivations for selling cover crop seed, 2) the types of cover crop seed most commonly sold, and 3) whether seed sales have increased over the past five to ten years. NRDC contacted all known and identifiable cover crop seed companies in the United States via phone and fax and requested that they complete a two-page questionnaire. Of the 55 companies asked to participate in our survey, 30 companies responded, for a response rate of 55 percent. Cover crops were defined in the survey as green manure crops or crops that were used for soil improvement purposes. Crops that were grown for harvest or for cash were not considered even though some may have been classified as cover crops.[16] Our results:

  • Cover crop seed sales have increased in most areas of the country over the last five and ten year period, with most seed companies and agricultural suppliers reporting estimated annual growth rates between 5 and 20 percent. A variety of reasons were cited for the increase in cover crop sales including heightened interest in sustainable agriculture and organic farming, desire to decrease use of chemical fertilizers for cost or environmental reasons, demand by farmers, and increased research on cover crops.

  • Of the 30 agricultural supplier and seed companies that participated in the survey, 63 percent were from California. While cover crops are not a new technology in California, this result reflects a resurgence in their use. Increased planting of grape acreage in the state and concomitant planting of cover crops was specifically mentioned.

  • Cover crop seed is sold for both annual and perennial cropping systems. There has been some debate as to whether cover crop use is more compatible with perennial orchard and vineyard cropping systems than with annual field, row, and vegetable cropping systems. This is because in perennial systems, land is not taken out of crop production, and rotations and planting schedules require less consideration compared with annual field crop production. Contrary to this supposition, however, companies sell seed for both types of systems.[17]

  • Annual cover crop species, including legumes, grasses, and cereals, are more commonly sold than perennial cover crop species.

  • Over 50 percent of cover crop companies provide consulting services to their clientele. Of the 17 companies who offer consulting services, 53 percent have added these services as a result of cover crop seed sales. At least two survey respondents in California believe that consulting services are particularly important because there is no "one size fits all" approach to using cover crops. Instead, cover crops are best utilized by farmers only when soil, climate, and planting location are taken into account. Therefore, simple cookbook type recommendations for planting and managing over crops are not often appropriate and necessitate consulting assistance.


Turning to Independent Pest Control Advisors and Information Systems

Implementing alternative agricultural systems can require that farmers acquire and integrate a great deal of information about their farm. Most of the farmers have found that managing pest problems using alternative management approaches is simply not as easy as using pesticides as the primary method of control. Under a conventional system, a farmer needs to know which pest is causing a problem and which pesticide to use to deal with it. Many alternative approaches are designed to prevent pest problems and thus require the integration of a wide body of information. Relying on natural enemy populations to help control key pests, for example, requires understanding complex interactions between pests and predators and how they are affected by changes in weather and cultural practices such as cultivation, pruning, and fertility management.

Farmers turn to a variety of sources for information about alternative management options. For farmers focused on reducing insecticide use, independent pest control advisors (PCAs) are far and away the most important source of information. Farmers perceive advice from independent PCAs as less biased than information coming from employees of pesticide dealers, packing houses, and processing companies, who may have a goal of selling pesticides. In most cases, farmers hire trained entomologists as consultants. On larger farms, farmers hire their own in-house PCA. As vineyardist John Ledbetter recollects,

I hardly used to pay much attention to what was going on in my fields. But now that I am using an IPM approach, I have had to hire an entomologist and several assistants to work with me full-time identifying pest problems and mapping out solutions. I spend a lot more time and money staying in touch with field conditions than I used to.

Many farmers personally do not have the time it takes to pay close attention to pest and predator populations in the field. PCAs are able to walk and "scout" fields and orchards on a regular, often weekly basis, keeping close tabs on whether and to what extent natural enemies or biologically based materials are working to control major pests. This allows farmers to eliminate the practice of applying sprays on a calendar basis. As Washington red raspberry grower Jerry Dobbins, puts it,

If I hadn't hired Tom [an independent PCA], I never would have seen these cost savings. I am spread so thin in the summer time that I can't possibly stay on top of the details of managing pests.

Having a PCA who can monitor field conditions also alleviates a great deal of anxiety for farmers. Natural enemies often do not provide visible control of pests until pest populations have risen well beyond levels at which farmers may want to take decisive action by applying an insecticide. This waiting period can be extremely stressful for farmers, since crop yields and quality often hang in the balance. Knowing that a PCA is in control of the situation is often all it takes to make it through this tough period.

In many cases, PCAs also enable farmers to avoid early season sprays of broad-spectrum insecticides, which are particularly detrimental to natural enemies. In many crops, PCAs will often recommend applying a narrow-spectrum, naturally occurring material such as Bacillus thuringiensis (Bt) to kill worm pests in order to preserve natural enemy populations and avoid creating secondary pest problems.

As Florida fresh market tomato grower, D.C. McClure, describes it,

The advantage of having a scout in the field twice a week is that it allows me to trust that the Bt is working and that I don't need to call in the "big guns."

In addition to PCAs, these farmers are also increasingly turning to computers and automated weather stations as a source of information about pests, natural enemies, the weather, and other factors affecting the performance of alternative pest management systems. One grower has installed weather stations, linked to a computer system, that enable him to easily and routinely track weather conditions, and thus pest development, within a number of micro-climates in his orchard. Pesticide use is reduced because he can target applications only when and where they are necessary. Another farmer has come to rely on a computer disease forecasting system that integrates a variety of information, such as weather conditions and cultural practices (any agricultural activity from land preparation to irrigation that is performed prior to harvest), to predict the appearance of particular diseases. This enables the farmer to reduce fungicide use by targeting sprays early in the season to keep disease pressure to a minimum and stretch out the time between future applications.


Adopting Conservation-Tillage Methods

Farmers producing grain crops have adopted conservation or "minimum" tillage methods that both reduce soil erosion and herbicide use. Although decreasing tillage is often associated with increased reliance on herbicides, these farmers have found the opposite to be true. Methods of conservation tillage that result in reducing reliance on herbicide use while also minimizing soil loss include: 1) a ridge-till system that involves planting crops such as corn, soybeans, and cotton in rows along a ridge, keeping crop residues between rows to act as a mulch to suppress weed growth, and banding herbicide applications at the base of crop rows and 2) incorporating a fall cover crop into crop rotation patterns to minimize tillage and herbicide use at planting time.


Switching to Biologically Based Pest Control Products

A number of farmers are able to substantially reduce synthetic insecticide use by using biologically based pest control products.

Biologically based materials . . .are those of natural origin or that are nature-identical, and are divided into the following product groups: bacteria, viruses, fungi, nematodes, mass-reared arthropods [beneficial insects], microbially produced toxins, behavior-modifying chemicals, botanical insecticides, and transgenic plants.[18]

The following products are of particular importance to one or more farmers in this report: 1) pheromone products designed to confuse the mating behavior of insects. These products are particularly important for pests such as the codling moth, which have no significant natural enemies; 2) the naturally occurring bacteria, Bacillus thuringiensis (Bt), which is effective against the larval stage of a wide variety of lepidopteran (i.e., moth and butterfly) pests but is harmless to beneficial insects; 3) release of mass-reared beneficial insects such Trichogramma, a parasitic wasp, which is effective against a number of lepidopteran pests; and 4) the botanical insecticide azadirachtin (Neemix), derived from the oil of the seed of the Neem tree, which can control a wide variety of pests through multiple modes of action, thereby decreasing the likelihood that resistance develops.[19] (For a discussion of pheromone use in U.S. agriculture, see the box below)


ADOPTION OF PHEROMONE TECHNOLOGY INDICATES GROWING ACCEPTANCE FOR BIOINTENSIVE IPM

Pheromones are an increasingly important tool in many IPM programs, and their use is one indicator of the extent of adoption of biointensive IPM practices in U.S. agriculture. Pheromones are a class of chemicals, called semiochemicals, that are produced by insects and used to modify types of behavior. Classes of pheromones include: sex, alarm, trail-marking, defense and aggregation.20 Practical applications of pheromones include use in monitoring systems (traps and lures) and mating disruption. When used to disrupt mating, pheromones have the potential to greatly reduce and in some cases entirely eliminate insecticide use. Pheromones are used in minute quantities, are practically non-toxic, and degrade relatively quickly. They are selective, do not kill biological control agents, and resistance is slow to develop. Pheromones are best applied as a preventive measure before pests emerge and are most effective if used over a large area.[21]

Less than ten years ago, use of pheromone technology was hampered by the high cost of synthesizing these complex structures and the difficulty of creating delivery systems that could emit pheromones in small amounts over a long time period. Attaining registration from the EPA was also prohibitively expensive and time-consuming.

Today, pheromone use is gaining in popularity, and growers are beginning to trust the efficacy of this unique approach to insect management. To learn more about pheromone use in agriculture, NRDC surveyed pheromone manufacturers and wholesalers of pheromone products used for mating disruption and monitoring. Our survey was designed to determine 1) the types of products most commonly sold and the target pest for which they are sold, 2) whether pheromone sales have increased over the last five to ten years, and 3) the opportunities and barriers for pheromone use.

A total of eight companies were identified as producers and wholesalers of pheromone products across the United States and three were interviewed by NRDC via phone and fax. [22] Our findings:

  • Most pheromone manufacturers and wholesalers are located in the western United States or have western representation, which may be an indication that pheromone use and demand is higher in this part of the country.

  • Pheromone products are sold to monitor and/or disrupt mating behaviors for a wide variety of lepidopteran insect pests, including codling moth, peach twig borer, pink bollworm, oriental fruit moth, and tomato pinworm.

  • Pheromone product sales have increased in the past five to ten years. This increase is related to a variety of factors, including increased demand within different pest management programs, decreased availability of effective insecticides, and concerns about increased pest resistance to synthetic insecticides. In the past six years, for example, sales of individual codling moth pheromone packages by Pacific Bio-Control increased ten-fold, from 3,000 to 30,000. [23]

  • The price of pheromone technology has decreased approximately five to ten percent during the past five to ten years. This result explains greater acceptance and use of pheromone products because cost has been viewed as a major barrier to the development (synthesis) and practical use of pheromones, particularly for mating disruption systems. Compared to synthetic insecticides, however, pheromone application costs remain high and present a barrier to widespread use.

  • In the past ten years, pheromone use has gained wider acceptance due to 1) the establishment and demonstration of effective commercial programs, 2) development of better delivery system technology, 3) decrease in cost of technology, and 4) grower trust in products.

  • The regulatory environment for the development and use of pheromones has improved and contributed to market expansion.



Alternative Agricultural Systems Can Be Profitable

The effectiveness of alternative pest and farm management methods depends on their ability to generate acceptable incomes for farmers. As Wendall Jack puts it,

For any farming system to really work, it has to be economical for the farmer. It can't just make you feel good or make you think you'll go to heaven if you do it.

All of the farmers in this report were selected because they have reduced pesticide use and reliance in an economically viable manner. They all made the transition from conventional pest management systems to alternative pest management systems while maintaining and, in many cases, improving the profitability of their operations. Their experiences, however, cannot be immediately transferred to other farms using a cookie-cutter or "one size fits all" approach. There is no one single recipe for successfully adopting alternative pest management systems and reducing pesticide use because a great deal is determined by site-specific pest, climate, and soil conditions as well as crop choice, market conditions, access to information, and the management skill of individual farmers.

These farmers' experiences, however, are supported by research results which suggest that alternative methods can be as profitable as conventional methods. For example, IPM techniques are often found to be more profitable than conventional, prophylactic use of pesticides. A 1994 review of 61 economic evaluations of farm-level IPM programs in cotton, soybeans, vegetables, fruits, peanuts, tobacco, corn, and alfalfa found that pesticide use, on average, decreased for seven out of eight commodities or commodity groups. Cost of production decreased or was unchanged in four out of the five commodities for which production cost changes were reported. Yields increased for six out of seven, and net returns increased in all seven commodities for which the changes were measured. The summarized studies evaluated a variety of IPM tactics, but particularly the use of scouting and economic thresholds. The authors conclude that because pesticide costs are a relatively small proportion of farmers' total production costs, small changes in total costs and yields due to IPM can result in substantial changes in net returns. [24]

It should be noted that this review also found that in 21 percent of the studies evaluated, IPM adoption resulted in increased pesticide use. This result may reflect the fact that these IPM programs were not biointensive, meaning they did not focus on the use preventive tactics and biological controls to keep pests within acceptable limits. Biointensive IPM programs focus on the use of pest management methods that both improve farmers' net profits and reduce pesticide use, risks, and reliance.

Available studies comparing the economic performance of alternative pest management systems (other than IPM) with conventional crop production suggest that farmers can earn higher returns with alternative systems.[25] While some alternative systems experience lower yields than conventional systems, lower costs of production often offset yield reductions, roughly equalizing farmers' net returns. Available studies focus on mid-western grain and row crop production, with fruit and vegetable production notably absent. In addition, most of the alternative systems evaluated in these studies are organic, thus making it difficult to determine farmer profits in situations in which synthetic pesticide use is reduced rather than entirely eliminated.

In general, the research documents the economic benefits of crop rotations and nitrogen-fixing cover crops. It indicates that alternative systems often become more profitable than conventional systems after a transition period during which soil quality and other on-farm biological processes are improved. It also suggests that alternative systems require increased family labor and management which, for part-time farmers, may be a barrier to adoption.


PROFIT POTENTIAL WITH ALTERNATIVE PEST AND FARM MANAGEMENT PRACTICES

Available economic studies comparing alternative agricultural systems (other than IPM) with conventional agricultural systems indicate that while alternative systems can experience lower yields than conventional systems, lower costs of production often offset yield reductions, roughly equalizing farmers' net returns. A brief review of several key studies follows.

In one study, for example, the practice of crop rotation was found to significantly increase net returns compared to continuous cropping. The study authors reviewed thirteen cropping systems in east central Nebraska over an eight-year period and found that organic systems that rotate crops have higher and less variable returns. Furthermore, the farmer's choice of organic, low-input, or conventional pesticide and fertilizer inputs had little impact on this result.[27]

A review of conventional, reduced-till and organic row crop and small grain systems in South Dakota over a seven-year period found that, except for labor costs, all direct costs were 27 to 49 percent less for the organic systems than for the conventional or reduced-till systems. Average net returns for the organic systems were either higher or equal to conventional systems. The organic crops did not receive price premiums. [28]

In Washington state, net returns for conventional wheat and barley production were compared to a low-input rotation involving nitrogen-fixing cover crops. Average annual overall variable costs, including the costs of pesticides and fertilizers, were lower for the low-input system. While the conventional system grossed higher returns, this was primarily because a crop was produced each year of the conventional system while the low-input system had a year of non-harvested cover crop. At market prices, however, the low-input system was more profitable. [29]

Conventional corn and soybean production in Iowa was compared with a reduced-chemical corn, oats, and meadow rotation. The costs of production for the reduced chemical system were half that of the conventional rotations. Yields for the low-input rotation were lower than conventional yields, but the returns for the low-input rotation were similar to the conventional system. Returns for the low-input system dropped below the conventional when hourly wages were assumed to be $20.00 or more. [30]

A recent study compares organic cash grain farming systems with conventional corn and soybean production in Pennsylvania over a ten-year period. This study found that after a transition period in which soil fertility and organic matter were developed, organic rotations produced corn and soybean yields comparable to the conventional rotation, but grew higher-value crops less frequently. The organic rotation required more family labor and management. The authors suggest that higher labor requirements for the organic system make it less profitable for part-time farmers, but that full-time farmers would find the organic rotation more profitable.[31]



Alternative Agricultural Systems Offer Multiple Environmental Benefits

Many farmers have adopted alternative agricultural systems which, in addition to reducing pesticide use, have resulted in other environmental and potential health benefits, including water quality protection, soil conservation, wildlife habitat enhancement, and recycling of urban waste. Some farmers, for example, have substantially reduced synthetic nitrogen fertilizers, thereby decreasing potential nitrate contamination of water resources. Many farmers utilize conservation tillage methods that help conserve soil resources. A number of farmers have developed farming systems that are compatible with and enhance wildlife habitat. To address rodent problems, for example, a few fruit and nut growers have installed boxes throughout their orchards to house hawks and other birds of prey. This enhances natural predation of rodents and provides habitat for important raptor species. One rice grower adopted the practice of flooding his fields in the winter to help control pest problems and provide important habitat for over-wintering water fowl. And some farmers have or are trying to develop soil-building programs that utilize municipal yard waste.



Farmers Experience Barriers to Adoption of Alternative Agriculture Systems

The statement is often made that if alternative farming systems were more profitable than conventional systems, then more farmers would be employing alternative approaches. While profitability is certainly a critical factor determining the extent to which alternative management methods are adopted, this argument ignores the vast number of documented barriers that make it difficult for farmers to adopt new systems of management that reduce pesticide use and reliance. Some barriers are of natural origin, such as regional soil and climate conditions that exacerbate pest problems. Others are more aesthetic, such as the widely-held opinion of many farmers that fields and orchards should be kept entirely free of weeds. Still others are created by government policies and programs that discourage alternative agricultural practices.

While the farmers in this report have overcome significant difficulties, their experiences concur with a number of reports that document extensive policy barriers to the development and adoption of alternative systems.[26] A few of the most important barriers are discussed below.


Lack of On-Farm Research and Education Programs

The number one barrier expressed by most of these farmers is the lack of research and education programs related to alternative farming systems.

When these farmers produced crops using conventional pest management methods, they were most likely to receive information about pest management from one or more of the following sources: 1) private consultants, many of whom were employed by chemical dealers, 2) employees of fruit warehouses or processing companies, 3) magazine advertisements, and 4) county extension agents. When they became interested in reducing pesticide use and investigating alternatives, few of these sources were helpful. And now that they are fully committed to implementing alternative methods, they see a tremendous lack of on-farm research focused on issues of their concern. For example, these farmers would like to see research that helps them perfect the use of cover crops in orchards and field crops to both improve soil quality and provide habitat for natural enemies of insect pests. They need research focused on improving soil quality as a means of preventing pest problems. They are interested in biological control of pests and improved mechanical methods for controlling weeds and preventing soil erosion.


Lack of Markets for Foods Grown Using Alternative Agriculture Systems

A number of these farmers, particularly those producing fresh fruits and vegetables, believe that lack of support in the marketplace is an important barrier to reducing pesticide use. As New York apple grower Chris Edmonds puts it,

I give 16 cents a bushel to the New York Apple Association, most of which goes to marketing, but none of it is focused on IPM. We need support in the marketplace, especially from consumers, for more growers to reduce pesticide use and farm more sustainably.


Grading and Cosmetic Standards Encourage Pesticide Applications

A number of these farmers produce fruits and vegetables whose production is influenced by grading and cosmetic standards imposed by federal, state, and private sectors. These standards dictate allowable levels of pest parts in processed foods and cosmetic quality standards for fresh produce and are often used indirectly to shape access to and prices in the marketplace.[32] In some cases, farmers perceive these standards as impediments to further reducing insecticide use. In a few cases, for example, processors enforce a "zero tolerance" for the presence of pests in harvested products destined to be canned, frozen, or otherwise processed. This imposes a strong incentive to spray insecticides to control "cosmetic" problems, such as worms and other pests that appear late in the growing season but which do not harm plant or fruit quality. As Francis Otto puts it,

Itís a legal requirement that we must abide by, but I think the zero tolerance should be changed to allow growers more flexibility to reduce chemical use.

Chris Edmonds expresses his interest in reducing pesticide use even further but is reluctant to end up with fruit that is cosmetically blemished and that would command a lower price. As he says,

If consumers were willing to tolerate more superficial blemishes, I know I could cut down on my chemical use even further . . .but I canít afford to do this with marketing standards the way they are.


Lack of Readily Available and Affordable Sources of Manure and Organic Material for Composting

Farmers interested in building the quality of their soils to encourage healthy plant production and prevent pest problems need manure and organic materials. Manure is often composted with organic materials, such as yard waste and crop residues, to reduce bulk and stabilize nutrient content. Manure can be an important source of nitrogen necessary for plant growth, particularly for organic growers who do not use synthetic sources of nitrogen. And as sources of organic material, manure and compost help improve soil quality by supporting soil microorganisms and invertebrates and improving nutrient cycling and soil tilth. Some farmers have an adequate supply of manure because livestock is incorporated into their operation; however, most farmers specialize in the production of certain crops and they need an outside source of manure. As California tomato and vegetable grower Jim Durst says,

One of our greatest challenges as organic growers, since we do not use synthetic fertilizers, is to create fertile and healthy soils. It requires constant attention.

Some farmers find it difficult and/or expensive to locate and haul manure to their farms. They are frustrated with a lack of access to organic materials to turn into compost. As Jackie Judice, Louisiana sugarcane farmer, puts it,

Why should yard waste just end up in a landfill when it is a valuable resource for farmers? I think local governments could provide an important service by making it easy for farmers to have access to municipal waste products.



Research and Education Programs Provide Critical Assistance

While the farmers profiled in this report differ in many ways, they all have one thing in common: their willingness to experiment and their openness to change. As problem-solvers, they have proactively figured out ways to address on-farm and environmental problems and have undertaken difficult, often financially risky, transitions in order to learn alternative management systems. Each of them had help along the wayóa person, publication, or program that provided information or technical support at critical junctures. In some cases, farmers turned to other farmers for information and advice. In other cases, government extension or cost-share assistance programs provided key assistance. (See the box below, "How the U.S. Department of Agriculture Assists Farmers," for a description of the federal governmentís role in agricultural research and education. The last section of Chapter 6 of the printed report, "The Next Step," includes examples of some of the programs that have proven or have the potential to be particularly helpful to these farmersí endeavors.


HOW THE U.S. DEPARTMENT OF AGRICULTURE ASSISTS FARMERS

Federal agricultural research programs are conducted through the USDA and the land-grant university research and education system. This system was originally created by the Morrill Act of 1862, which provided a grant of federal land to states as an endowment for public universities.33 There are currently three principal agencies responsible for conducting research, education, and extension activities within USDA, including the Agricultural Research Service (ARS), the Cooperative State Research, Education and Extension Service (CSREES), and the Economic Research Service (ERS).

ARS was established in 1953 as USDA's in-house research agency. [34] The agency maintains a network of national and international laboratories designed to provide access to agricultural information and develop new knowledge and technology needed to solve technical agricultural problems of broad scope and high national priority.[35]

CSREES is a national research and education network designed to advance research, extension, and higher education in food and agricultural sciences. CSREES combines the functions of two formerly separate agencies, the Cooperative State Research Service and the Extension Service. It administers grants to land-grant colleges and state agricultural experiment stations (SAESs). SAESs include field sites, research farms, and laboratories that provide state-specific agricultural information. CSREES partially funds local extension programs, which facilitate the transfer of methods and practices developed by the agricultural colleges and experiment stations to farmers in the field. Over 9,600 local extension agents are currently employed in 3,150 counties in the United States.[36] CSREES also administers the National Research Initiative, a competitive grants program that supports research to solve agricultural and environmental problems.

ERS conducts economic analyses to address efficiency, efficacy, and equity issues related to agriculture, food, the environment, and rural development. ERS activities involve research and development of economic and statistical indicators on a broad range of topics. [37]



Alternative Pest Management Practices Exist Along a Continuum

Alternative pest management practices, while they exist in almost infinite variety, are increasingly being described along a continuum that represents various degrees of reliance on pesticides. Researchers at Consumers Union (CU) and World Wildlife Fund (WWF) recently developed an "IPM Continuum" that is divided into four zones, ranging from those IPM systems that are scarcely distinguishable from pesticide-dependent systems to those that rarely, if ever, require pesticides.[38] The principal characteristic of IPM systems along this continuum is their degree of reliance on biologically based, prevention-oriented practices relative to their reliance on pesticides and treatment-oriented practices.

World Wildlife Fund (WWF) has used this continuum to describe a "Pesticide Reduction Spectrum."[39] The spectrum includes a variety of pesticide reduction strategies ranging from those that are highly reliant on pesticides to those that are able to eliminate the need for chemical intervention. The spectrum is divided into four parts and includes: 1) pesticide control tactics such as proper disposal of pesticide containers and use of field edge practices, such as filter strips, to reduce the volume of pesticides reaching water bodies, 2) efficient, chemical-intensive IPM strategies that generally entail greater precision and efficiency in applying pesticides, 3) multi-tactic IPM strategies that involve use of crop rotations and cover crops, and 4) biointensive systems that work with and enhance naturesí pest management mechanisms through primary reliance on biological and cultural methods.

In general, the farmers in this report have reduced pesticide use and reliance by adopting alternative pest management methods that fall along a continuum similar to the WWFís Pesticide Reduction Spectrum. We use three segments of the WWF spectrum as a basis for grouping the farmer profiles.

In selecting where to place the farmer profiles along the spectrum, we focused on the principal tools each farmer used to achieve reductions in pesticide use and the degree of reliance on alternative agricultural methods. The grouping scheme is by no means absolute and some farmers may belong in more than one category. And within each grouping, there is variation in terms of the degree of reliance on pesticides. Furthermore, farmers placed at the beginning of the continuum have by no means displayed less effort toward the goal of reducing pesticide use and reliance. Rather, this placement most likely represents the inherent difficulty involved in reducing pesticide reliance within a farmerís particular cropping system. Regardless of how far each farmer has progressed along the pesticide reduction spectrum, he or she has taken the important step of seeking and experimenting with alternative pest and farm management practices.


Efficient, Chemical-Intensive IPM Strategies

Fewer than 30 percent of the farmers we interviewed still rely substantially on synthetic chemicals for pest control but have accomplished significant reductions in one or more categories of pesticide use by eliminating "calendar" or prophylactic pesticide applications and by increasing the accuracy and efficiency of pesticide applications. Fruit and vegetable growers in this category have been able to reduce synthetic insecticide use between 21 and 81 percent and synthetic fungicide use between 40 and 79 percent. Row and field crop farmers have reduced herbicide use between 33 and 66 percent. Most of these farmers employ independent PCAs to closely monitor field and orchard conditions. They use spray rig attachments that apply pesticides more uniformly than conventional spray rigs. In some cases they have replaced or reduced organophosphate insecticide use with the naturally occurring bacteria, Bacillus thuringiensis. In one case, synthetic herbicide use is reduced by applying it along a narrow band at the base of the crop rather than to the entire row. In another instance, synthetic herbicide use is reduced by precision-grading, or leveling, of fields, which facilitates winter flooding; a flooded field suppresses weed growth. A number of these farmers are also experimenting with other alternative practices.


Multi-Tactic IPM Strategies

Forty percent of the farmers profiled in this report are mid-way along the pesticide reduction spectrum. They integrate a variety of tactics that reduce pesticide use and reliance and move them farther toward the biointensive end of the pesticide reduction spectrum. Various combinations of the following tactics are used: independent PCA services, cover crops, crop rotations, conservation tillage, and biologically based pest control products. A number of farmers in this category, particularly corn, soybean, and cotton producers, have developed "minimum" tillage methods that both conserve soil and reduce herbicide use. Reductions in synthetic herbicide use range from 25 to 80 percent. Reductions in synthetic insecticide use range from 46 to 100 percent and reductions in synthetic fungicide use range from 10 to 50 percent. Three farmers in this category produce some of their products organically, in which case synthetic pesticide use is eliminated.


Biointensive Systems

Over 30 percent of the farmers we discuss in this report focus on working with and enhancing naturesí pest management mechanisms and rely primarily on biological and cultural methods. These farmers perceive and manage pest problems as a component of an overall system in which all aspects of crop and, in some cases, livestock production are inter-related. While they use many multi-tactic IPM strategies, they emphasize development of healthy plants that can withstand higher pressure from pests. Improving soil structure and fertility through the regular addition of organic matter from cover crops (incorporated into the soil), crop residues, manure, and compost is regarded as of utmost importance to sustaining healthy plants. Diverse rotations and cover crops are also critical elements of biointensive systems.

Two farmers in this category have converted row crop acreage to pasture and utilize intensive rotational grazing (IRG) to raise dairy cows. IRG significantly reduces the use of synthetic pesticides and fertilizers while also enhancing pasture growth and cow health. Four of the farmers in this category have completely eliminated their use of synthetic pesticides, principally through the use of organic production practices. For non-organic farmers in this category, reductions in synthetic insecticide use range from 75 to 100 percent. Reductions in synthetic herbicide use range from 56 to 100 percent, and one farmer has reduced synthetic fungicide use 58 percent.

Most of the farmers we interviewed intend to continue to reduce pesticide use and further refine and improve their alternative pest management systems. Many of them hope that, over time, they will be able to profitably move toward greater reliance on techniques used at the biointensive end of the pesticide reduction spectrum.



Notes

1. For the purposes of calculating reductions in pesticide use, we chose to distinguish between synthetic pesticides and biologically based pest control products. The methodology section in Chapter 1 describes this distinction.

2. National Research Council, Ecologically Based Pest Management Systems: New Solutions for a New Century, National Academy Press, Washington, D.C., 1996, pp. 11–12.

3. National Research Council, Ecologically Based Pest Management: New Solutions for a New Century, p. 29.

4. National Research Council, Ecologically Based Pest Management: New Solutions for a New Century, p. 26.

5. Pimentel, David, et. al., “Environmental and Economical Costs of Pesticide Use," BioScience, November 1992, vol. 42, no. 10, p.754.

6. Office of Technology Assessment, Beneath the Bottom Line: Agricultural Approaches to Reduce Agrichemical Contamination of Groundwater, U.S. Congress, U.S. Government Printing Office, Washington, D.C., November 1990, p. 104.

7. Pimentel, David, et. al., “Environmental and Economical Costs of Pesticide Use," p. 757.

8. Bugg, Robert L., “Earthworm Update," Sustainable Agriculture Technical Reviews, Sustainable Agriculture Research and Education Program, University of California, Summer 1994, vol. 6, no. 3, p. 3.

9. Soil Science Society of America, Glossary of Soil Science Terms, Madison, Wisconsin, 1997, p. 98.

10. National Research Council, Soil and Water Quality: An Agenda for Agriculture, National Academy Press: Washington, D.C., 1993, p. 38.

11. National Research Council, Soil and Water Quality: An Agenda for Agriculture, p. 22.

12. Parr, J. F., “Soil Quality: Attributes and Relationship to Alternative and Sustainable Agriculture," American Journal of Alternative Agriculture, vol. 7, no. 1 and 2, 1992, pp. 5–11.

13. National Research Council, Alternative Agriculture, National Academy Press: Washington, D.C., 1989, pp. 3–4.

14. Miller, P.R., et. al., Cover Crops for California Agriculture, Division of Agriculture and Natural Resources, University of California, 1989, pp. 4–5.

15. Ingels, Chuck, et. al., “Selecting the Right Cover Crop Gives Multiple Benefits," California Agriculture, 1994, vol. 48, no. 5, pp. 43–48.

16. Companies were not randomly selected but were identified with the help of an industry expert and a seed company directory. Of the companies that did not participate, five were eliminated because they sold cover crop seed for cash, hay, or forage crops and not specifically for green manure crops or for soil improvement. Twenty other companies were eliminated from the sample because they were not willing to participate.

17. Differences in the volume of sales of cover crop seed for annual and perennial cropping systems was difficult to measure because volume of sales by cropping system is not tracked by seed companies.

18. Ridgeway, R.L., et. al., “Biologically Based Pest Controls: Markets, Industries and Products," Beltsville Agricultural Research Center, Agricultural Research Service, U.S. Department of Agriculture, May 20, 1994.

19. Olkowski, William, et. al., Common-Sense Pest Control: Least Toxic Solutions for Your Home, Garden, Pets and Community, The Taunton Press: Newton, Connecticut, 1991, p. 123.

20. Kirsch, Phillipp, “Pheromones: their Potential Role in Control of Agricultural Insect Pests," American Journal of Alternative Agriculture, 1988, vol. 3, nos. 2 & 3, pp. 83-97; Pedigo, Larry P., Entomology and Pest Management, Macmillan Publishing Company: New York, NY, 1989, p. 646.

21. Adapted from Shin Etsu Chemical Company, Ltd., Pheromones, Shin-Etsu Chemical Company, Ltd., Toyko, Japan, 1995.

22. The companies that were contacted were not randomly selected but were identified with the help of an industry expert and an agricultural extensionist. Of the companies that did not participate, two were eliminated because one was discovered to be a distributor, not a wholesaler or producer, and another had gone out of business. Three other companies failed to respond.

23. Personal communication with Don Thompson, Pacific Bio-Control, September 9, 1997. Codling moth packages include enough pheromone to disrupt mating on one acre.

24. Norton, George W. and Jeffrey Mullen, Economic Evaluation of Integrated Pest Management Programs: A Literature Review, March 1994, pp. i–ii.

25. Helmers, Glenn A., Michael R. Langemeier, and Joseph Atwood, “An Economic Analysis of Alternative Cropping Systems for East-Central Nebraska," American Journal of Alternative Agriculture, vol. I., no. 4, 1986, pp. 153158; Smolnik, James D., et al., “The Relative Sustainability of Alternative, Conventional and Reduced-Till Farming Systems," American Journal of Alternative Agriculture, vol. 10, no. 1, 1995, pp. 25–35; Goldstein, Walter A. and Douglas L. Young, “An Agronomic and Economic Comparison of Conventional and Low-Input Cropping System in the Palouse," American Journal of Alternative Agriculture, 1987, vol. II., no. 2, pp. 51–56; Chase, Craig and Michael Duffy, “An Economic Comparison of Conventional and Reduced-Chemical Farming Systems in Iowa," American Journal of Alternative Agriculture, 1991, vol. 6, no. 4, pp. 169–173; Hanson, James C., et. al., “Organic versus Conventional Grain Production in the mid-Atlantic: An Economic and Farming System Overview," American Journal of Alternative Agriculture, 1997, vol. 12, no. 1, pp. 2–9.

26. National Research Council, Alternative Agriculture, pp. 10–13; Curtis, Jennifer, et. al., Harvest of Hope: The Potential for Alternative Agriculture to Reduce Pesticide Use, Natural Resources Defense Council, May 1991, pp. 97–114; Office of Technology Assessment, Beneath the Bottom Line: Agricultural Approaches to Reduce Agrichemical Contamination of Groundwater, pp. 253–322; Benbrook, Charles, et. al., Pest Management at the Crossroads, Consumers Union, pp. 143–170.

27. Helmers, Glenn A., Michael R. Langemeier, and Joseph Atwood, “An Economic Analysis of Alternative Cropping Systems for East-Central Nebraska," pp. 153–158.

28. Smolnik, James D., et al., “The Relative Sustainability of Alternative, Conventional and Reduced-Till Farming Systems," pp. 25–35.

29. Goldstein, Walter A. and Douglas L. Young, “An Agronomic and Economic Comparison of Conventional and Low-Input Cropping System in the Palouse," pp. 51–56.

30. Chase, Craig and Michael Duffy, “An Economic Comparison of Conventional and Reduced-Chemical Farming Systems in Iowa," pp. 169–173.

31. Hanson, James C., et al., “Organic versus Conventional Grain Production in the Mid-Atlantic: An Economic and Farming System Overview," pp. 2–9.

32. Benbrook, Charles, et. al., Pest Management at the Crossroads, p. 153.

33. Curtis, Jennifer, et. al., Harvest of Hope: The Potential for Alternative Agriculture to Reduce Pesticide Use, p. 97.

34. U.S. General Accounting Office, USDA Research and Extension Agencies: Missions, Structures, and Budgets, February 18, 1993, p. 8.

35. U.S. Department of Agriculture Web site: (www.ars.usda.gov/nps/mr).

36. U.S. Department of Agriculture Web site: (www.reeusda.gov/new/about/csreesa2.htm#mission). State governments provide a significant source of funding to extension personnel. In addition to rural agricultural priorities, extension activities extend into urban and suburban communities.

37. U.S. Department of Agriculture Web site: (www.usda.gov/ocfo/annlplan/ers).

38. Benbrook, Charles, et. al., Pest Management at the Crossroads, pp. 27–28; Hoppin, Polly J., “Reducing Pesticide Reliance and Risk Through Adoption of IPM: An Environmental and Agricultural Win-Win," in Proceedings of the Third National IPM Symposium/Workshop . . . Broadening Support for 21st Century IPM, edited by Sarah Lynch, et. al., Publication Number 1542, Economic Research Service, U.S. Department of Agriculture, February 27–March 1, 1996, pp. 12–16.

39. Hoppin, Polly J., et. al., Reducing Reliance on Pesticides in Great Lakes Basin Agriculture, World Wildlife Fund, Washington, D.C., 1997, pp.4–5.

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