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Toward Sustainability: A Plan for Collaborative Research on Agriculture and Natural Resource Management (1991)

Chapter: Appendix F: Integrated Pest Management for Sustainability in Developing Countries

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Suggested Citation:"Appendix F: Integrated Pest Management for Sustainability in Developing Countries." National Research Council. 1991. Toward Sustainability: A Plan for Collaborative Research on Agriculture and Natural Resource Management. Washington, DC: The National Academies Press. doi: 10.17226/1822.
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APPENDIX F

Integrated Pest Management for Sustainability in Developing Countries

Clive A. Edwards, H. David Thurston, and Rhonda Janke

Losses of crops to pests in developing countries are extremely large. Preharvest losses are estimated at 36 percent of potential yield, and postharvest losses at 14 percent (Agency for International Development, 1990). Control of pests still depends heavily on pesticides. Unless the introduction of pests into new regions is prevented by quarantine measures or eradication, the control of imported and indigenous pests must depend on pesticides until effective pest management strategies can be developed.

Integrated pest control (IPC) and integrated pest management (IPM) were originally developed in relation to insect pest control, beginning with the publication of Stern et al.'s classic The Integrated Control Concept (1959). The original concept emphasized the blending of biological and chemical control measures. It was later broadened (Smith and Reynolds, 1965) to refer to “a system which uses all suitable methods in as compatible a manner as possible.” This led to the further definition by the Food Agriculture Organization (1967) of IPM as “a pest management or integrated control system which in the context of the associated environment and the population dynamics of the pest species, utilizes all suitable techniques and methods in as compatible a manner as possible and maintains pest population levels below those causing economic injury.” However, neither this definition nor that of Norton and Holling (1979), which stated that the aim of

Clive A. Edwards is professor of entomology at The Ohio State University, H. David Thurston is professor of plant pathology at Cornell University, and Rhonda Janke is section leader within the Agronomy Department at the Rodale Research Center.

Suggested Citation:"Appendix F: Integrated Pest Management for Sustainability in Developing Countries." National Research Council. 1991. Toward Sustainability: A Plan for Collaborative Research on Agriculture and Natural Resource Management. Washington, DC: The National Academies Press. doi: 10.17226/1822.
×

IPM was “to develop alternative, ecologically desirable tactics for use in suppressing major pests,” makes explicit the need to minimize the use of pesticides. Integrated pest management, however, encompasses more than limiting the use of pesticides when necessary to avoid economic damage (normally termed supervised control). Probably the best definition of IPM is that of the Office of Technology Assessment: “The optimization of pest control measures in an economically and ecologically sound manner accomplished by the coordinated use of multiple tactics to assure stable crop production and to maintain pest damage below the economic injury level while minimizing hazards to humans, animals, plants and the environment” (Office of Technology Assessment, 1990).

Many of the techniques examined as components of IPM—forecasting of pest attacks, development of economic injury thresholds, use of pheromones in pest monitoring, use of selective pesticides, use of resistant crop varieties, timing of crop planting, and use of appropriate cultivations and crop rotations—have already been incorporated into current pest control practices and have led to more rational use of pesticides. Although successful IPM programs have been developed for glasshouse crops and orchard fruit in developed countries, and for some field crops (for example, cotton and rice) in developing countries, adoption of truly integrated pest management programs has been relatively slow, even for insect pests.

The concept of IPM was developed originally for the control of invertebrate pests, but its principles were soon adopted successfully for the control of diseases and, later, weeds (see Table F-1). Although many definitions of IPM have been advanced, there is general agreement on the conceptual aspects. All definitions include a management approach to pest problems that involves methodological and disciplinary integration and consideration of environmental and social values. The common aim of most IPM programs is to use multiple tactics to maintain pest damage below the economic injury level and at the same time provide protection against hazards to humans, animals, plants, and the environment.

In most crop production systems or agroecosystems, the development of an IPM program involves the following steps:

  1. Identify the overall pests in the system, including

    • major pests that are perennial pests and usually cause damage above the economic injury level;

    • occasional, minor, or secondary pests that cause damage above the economic injury level only occasionally;

    • potential pests that normally do not cause economic losses; and

    • migratory pests that can cause serious damage on a periodic basis.

  1. Develop suitable monitoring or forecasting techniques. This involves the measurement of pest populations (numbers of eggs, larvae, insects, spores,

Suggested Citation:"Appendix F: Integrated Pest Management for Sustainability in Developing Countries." National Research Council. 1991. Toward Sustainability: A Plan for Collaborative Research on Agriculture and Natural Resource Management. Washington, DC: The National Academies Press. doi: 10.17226/1822.
×

mycelia, nematode cysts on adults, seeds, or weeds) or amount of damage or loss.

  1. Establish economic thresholds, that is, the pest population or disease incidence levels that cause losses in crop value that exceed the cost of pest management. It may be difficult to establish such levels for some weeds and diseases.

  2. Develop a pest management strategy. It is necessary to identify the least hazardous chemical that can be used, with minimal dose if needed, and the appropriate cultural and biological techniques that can be integrated into a pest management strategy. The aim is to maintain pest numbers and resultant damage at economically acceptable levels with minimal use of chemicals. IPM usually targets containment rather than eradication.

  3. Identify extension and outreach programs that can assist in developing and implementing a pest management strategy.

A number of pest management programs have been developed using this overall approach, particularly for pests of cotton and rice in developing countries. The programs have led to significant decreases in the use of pesticides and in such associated problems as the development of resistance to pesticides. There is an urgent need, however, to develop pest management programs that involve the integration of insect, nematode, disease, and weed management for major tropical crops. Such programs would provide the base for modifications to cover regional differences in the kind and intensity of pest attacks.

THE PRACTICE OF INTEGRATED PEST MANAGEMENT

Integrated Arthropod Pest Management

The integrated management of arthropod pests has had mixed successes. Most programs have been based on first identifying economic thresholds of damage below which control is not economically practical. Once that decision is reached, minimal amounts of pesticides are used, combined with such cultural and biological methods of control as may be available for that particular crop and region. Since pests occur in populations that are part of complex associations with those of other species, IPM must have a thorough base in ecology.

The original IPM concepts were developed for control of insects and mites. The driving force was probably the relatively high mammalian toxicity of many insecticides and fairly rapid development of cross-linked resistance to many pesticides (Edwards, 1973a,b). Most pest management programs involve some use of chemicals, and thus integrating the use of chemicals with a wide range of other techniques must be understood. Most elements

Suggested Citation:"Appendix F: Integrated Pest Management for Sustainability in Developing Countries." National Research Council. 1991. Toward Sustainability: A Plan for Collaborative Research on Agriculture and Natural Resource Management. Washington, DC: The National Academies Press. doi: 10.17226/1822.
×

TABLE F-1 The Potential of Manipulating Chemical, Cultural, and Biological Controls for Integrated Pest Management

 

Weeds

Insects

Pathogens

Current Practices

Developed Countries

Developing Countries

Developed Countries

Developing Countries

Developed Countries

Developing Countries

Chemical inputs

 

Pest threshold

a

0

+++

+

+

0

Minimum pesticide use

++

0

++

+

+

0

Forecasting

a

0

+

+

+

0

Cultural inputs

 

Tillage

+

+++

a

+

a

+

Rotation

+

++

+

+++

+

++

Fallow

0

+

+

+

+

+

Cropping patterns/intercropping

+

+++

0

++

0

+++

Mulches

+

++

0

0

0

++

Timing of practices

+

++

+

++

+

++

Flooding

0

++

0

+

0

++

Burning

a

+

+

+

+

+

“Clean” seed

+++

+

0

0

+++

+

Organic soil amendments

a

+

+

+

+

+++

Resistant crop varieties

a

a

++

+++

+++

+++

Trap crops

0

0

+

0

+

+

Green manures

a

a

0

0

+

+

Suggested Citation:"Appendix F: Integrated Pest Management for Sustainability in Developing Countries." National Research Council. 1991. Toward Sustainability: A Plan for Collaborative Research on Agriculture and Natural Resource Management. Washington, DC: The National Academies Press. doi: 10.17226/1822.
×

Biological control inputs

 

Genetically engineered crop varieties

0

0

0

0

0

0

Genetically engineered microorganisms

0

0

a

0

0

0

Microherbicides

a

0

0

0

0

0

Allelopathy

a

0

0

0

0

0

Pest pathogens

a

a

+

a

+

+

Entomopathogenic nematodes

0

0

a

0

0

0

Pheromones

0

0

++

a

0

0

Sterile male release

0

0

+

0

0

0

Disease antagonists

0

0

0

0

+

+

Introduction of natural enemies

+

+

+

+++

0

0

NOTE: +++, Major; ++, intermediate; +, small; 0, none.

a Examples exist, but are of minor importance.

Suggested Citation:"Appendix F: Integrated Pest Management for Sustainability in Developing Countries." National Research Council. 1991. Toward Sustainability: A Plan for Collaborative Research on Agriculture and Natural Resource Management. Washington, DC: The National Academies Press. doi: 10.17226/1822.
×

of integrated insect management can be classified under the headings of regulatory activities, biological control, or cultural control.

Regulatory Activities

Most regulatory activities are directed at preventing the introduction of pests into new areas or regions, mainly through quarantine measures. Some eradication programs, such as those for the Mediterranean fruit fly in Florida and California, have been relatively successful, but the cost in both economic and environmental terms probably precludes their implementation in most developing countries unless the program involves nonchemical methods.

Cultural Control

Before the advent of modern insecticides, manipulation of farming practices was the main pest control tool available to farmers. Some of the cultural practices available were well established and are still used extensively in developing countries. Others are relatively new and need further testing. The cultural techniques available include the following:

TILLAGE. It was widely thought that deep moldboard plowing had beneficial effects on pest insect populations, and there are some situations in which it is true, particularly for long-lived pests, such as wireworms and chafers. With the advent of conservation tillage, however, there is good evidence that some insect pest problems are decreased by cultivations, but that others are made more serious. In general, conservation tillage tends to decrease the problems associated with a range of different pests (Stinner and House, 1990).

RESISTANT CROP VARIETIES. The use of crop varieties that resist attack by arthropod pests has been a major tool in minimizing the use of pesticides and developing pest management strategies, particularly in developing countries. The international agricultural research centers have implemented large seed bank programs as the basis for developing resistant crop varieties. This process may be accelerated through genetic engineering of new strains and varieties.

ROTATIONS AND F ALLOWING. The use of crop rotations has long been a major strategy in minimizing arthropod pest attacks. Such rotations are essential in controlling long-lived, soil-inhabiting insect pests effectively. More research is needed, however, to identify the rotations that effectively minimize attack by many insect pests and to define the role that fallow periods play in this approach.

Suggested Citation:"Appendix F: Integrated Pest Management for Sustainability in Developing Countries." National Research Council. 1991. Toward Sustainability: A Plan for Collaborative Research on Agriculture and Natural Resource Management. Washington, DC: The National Academies Press. doi: 10.17226/1822.
×

CROPPING PATTERNS. It has long been understood that crop diversity decreases arthropod pest attack. Crop diversity minimizes populations of susceptible plants and maximizes the potential of natural enemies by providing alternative hosts and habitats. Much more research is needed on the effects of relatively new cropping patterns, such as intercropping, intersowing, undersowing, and amalgamation of tree growing with annual crops. There is good evidence that such cropping patterns are very effective in minimizing arthropod pest attacks.

TIMING OF FARM O PERATIONS. The attacks by many arthropods pests can often be minimized by careful study of their life cycles and the timing of farm operations, such as sowing and harvesting, to reduce pest attacks and avoid carryover of pests from crop to crop.

Biological Control

USE OF INSECT PATHOGENS. Many arthropods are attacked and killed by viral, bacterial, or fungal pathogens. A number of these, notably Bacillus thuringiensis and Beauvaria bassiana, have been developed as commercial arthropod control agents. The potential of these control agents has been reinforced by the ability to engineer them genetically to control particular groups of pests. The registration of such organisms for commercial release, however, is problematic due to anxieties concerning their environmental impact.

ENTOMOPATHOGENIC NEMATODES. Many insects and other arthropods are attacked by parasitic nematodes, of which the most important is Neoaplectana carpocapsae (Edwards and Oswald, 1981). There are many strains of these nematodes, all with different characteristics. But because nematode preparations can be formulated like a chemical pesticide and persist in soil for several months, they have considerable potential in arthropod pest management programs.

PHEROMONES. Many insect species possess sex attractants that attract the insects over long distances. The chemicals have been isolated, identified, and produced synthetically for many pest species. They can be used to disrupt mating or to attract insects to small areas where they can be killed chemically or by other means.

RELEASE OF STERILE MALES. A number of insect pests have been controlled successfully by rearing the male insects, sterilizing them by irradiation, and then releasing them in large numbers in the pest's territory. The sterile males mate with females to produce nonviable offspring or in some

Suggested Citation:"Appendix F: Integrated Pest Management for Sustainability in Developing Countries." National Research Council. 1991. Toward Sustainability: A Plan for Collaborative Research on Agriculture and Natural Resource Management. Washington, DC: The National Academies Press. doi: 10.17226/1822.
×

cases, no offspring. This technique was used very successfully to combat cattle screwworms in the southern United States.

Practical Examples of Insect Pest Management Programs

Cotton provides one of the best examples of a successful pest management program. Cotton is susceptible to a diverse range of pests, and a long and extensive record of heavy pesticide use is associated with its production. Wherever insecticides have been employed, a dramatic initial success has ensued for several years. In all cases, however, the number of pest species increased. This, combined with the gradual development of resistance, increased the need for insecticides, but little increase in yields has resulted. The net effect is a situation worse than the original. In Texas, for instance, the boll weevil and pink bollworm were the major pests. When heavy insecticide use was introduced, two new pests, another bollworm and tobacco budworm, developed as serious pests. Insecticide resistance soon followed. Had an effective IPM program not been developed, many farmers would have been forced out of business. The IPM program involves maintaining pest and natural enemy populations, shredding stalks and plowing in crop remnants to minimize pest overwintering, using selective insecticides timed to minimize effects on natural enemies, and using mechanical strippers, which kill bollworm larvae during harvest. Similar successes using different combinations of measures have been achieved in other parts of the world, especially, in Egypt and the Sudan.

Successful integrated insect pest management programs have also been implemented in the rice paddies of China, The Philippines, Indonesia, and Malaysia. Those programs have emphasized minimal dosing with granular insecticides, and only when economic thresholds are reached; using pest-resistant varieties; forecasting pest attack from light-trap catches and surveillance programs; timing of planting; flooding; trap cropping; using the parasite Trichogramma; using Bacillus thuringiensis; keeping ducks on rice paddies; and incorporating residues into soil. Successful integrated insect pest management programs have also been developed for maize, fruit, forest trees, brassicae, and other crops.

Integrated Disease Management

In developing countries, plant diseases have been given less attention than insect pests. As a result, integrated disease management has not had the attention it deserves. Estimates of global pest losses seldom break down the figures as to the type of pest, but in some of the most comprehensive studies of losses due to pests, the losses due to insects and diseases were similar.

Suggested Citation:"Appendix F: Integrated Pest Management for Sustainability in Developing Countries." National Research Council. 1991. Toward Sustainability: A Plan for Collaborative Research on Agriculture and Natural Resource Management. Washington, DC: The National Academies Press. doi: 10.17226/1822.
×

Because fungicides have not caused as serious a toxicological problem for humans and wildlife as have many insecticides, less attention has been focused on their overuse or misuse. In addition, many plant pathogens cannot be controlled with chemicals, and thus pest management tactics other than the use of chemicals have been employed for decades, even during the “golden age” (1960s to 1970s) of pesticides.

Plant pathologists have usually emphasized prevention of plant diseases, rather than their eradication when they occur. Their approaches to disease management have focused on the use of chemicals only occasionally, not only because relatively few chemicals have been effective against internal plant pathogens, but also because many chemicals have not been cost-effective against pathogens, especially soil-borne pathogens. In addition, the economic return from crops such as cereals and forages has seldom been sufficient to justify the use of chemicals.

Approaches to Integrated Disease Management

Five major approaches have been used in integrated disease management efforts. First, regulatory activities are used to prevent the entry of pathogens into a crop-growing region or a crop. These include quarantines and other activities that regulate the sale and transport of infected seeds or propagating materials.

Second, host resistance, or the use of plant resistance to disease, has been a major disease management approach. Disease-resistant plant varieties developed by plant pathologists and breeders are grown on 75 percent of the land in crop production in the United States. For small grains and alfalfa, 95 to 98 percent of U.S. crops are planted with varieties resistant to at least one pathogen (National Academy of Sciences, 1968). Scientific breeding of plants for disease resistance did not begin until after the disastrous potato late blight epidemic in Ireland in 1845, as a result of which an estimated 1 million Irish people died during the ensuing famine. Traditional farmers, however, have been selecting for disease resistance for millenniums. Many of the major crops on which humans depend for food are constituted primarily of cultivars or races selected before modern agricultural science began. These races are usually genetically diverse and in balance with the environment and endemic pathogens. They are dependable and stable, and although not necessarily high yielding, they will yield a crop under all but the worst conditions. The conservation and possible use of these races in breeding schemes should be considered a priority in disease management programs.

A third approach, chemical control, is problematic, as noted, because few chemicals are available to control diseases caused by bacteria and viruses. Viruses cannot be controlled by chemicals, other than through their vectors.

Suggested Citation:"Appendix F: Integrated Pest Management for Sustainability in Developing Countries." National Research Council. 1991. Toward Sustainability: A Plan for Collaborative Research on Agriculture and Natural Resource Management. Washington, DC: The National Academies Press. doi: 10.17226/1822.
×

Until the 1970s, almost all chemicals used to control fungi (fungicides) were broad-spectrum chemicals, applied to external plant surfaces, and they were generally ineffective against internal pathogens. Since most plant pathogens are sessile, the chemicals had to be present on plants in nearly a continuous layer before the pathogen arrived; if the pathogens did not come in contact with the fungicide where they were deposited, they could escape its effects. (Most insects, in contrast, are mobile and come in contact with a toxic insecticide even if it does not occur in a continuous layer.) For certain diseases, however, fungicides are the only known management practice available.

Unfortunately, overuse of pesticides in traditional farming systems is common where the pesticides are available and affordable. Although traditional farmers may have considerable knowledge of their agroecosystems, their knowledge seldom includes information regarding the effectiveness of different chemical pesticides, and usually they have to rely on sources outside their traditional culture for advice. The quantity of pesticides used by traditional farmers in developing countries is still very small. The high cost of pesticides seriously limits their use in developing countries, since few farmers can afford to use them. Nonetheless, expectations regarding the effects of pesticides are often unrealistically high. For example, Rosado-May et al. (1985) interviewed 59 farmers in Tabasco, Mexico, about their management practices for the fungus disease web blight of beans (Thanatephorus cucumeris). Although farmers used several cultural methods of management, all of those interviewed said they were expecting a chemical solution to the problem.

Drying agents, such as ashes and chalk, for crops in storage and natural or nontoxic pesticides for control of insect vectors and pathogens are often effective in controlling disease, and their use should be encouraged wherever feasible as alternatives to toxic pesticides.

Fourth, biological control, or the destruction or reduction in populations of one organism by another, is common in natural ecosystems. Such interactions can be used in a variety of ways in agroecosystems to manage plant pathogens. Traditional farmers in developing countries have used this approach to control soil diseases, for example, through the development of suppressive soils and the use of antagonistic plants. The addition of large amounts of organic matter to soils by Chinese farmers, which often produces suppressive soils, is probably one of the oldest biological control practices. Historically, many agricultural systems have incorporated large quantities of organic matter into soil, which results in less soil-borne disease and other important agronomic benefits. This practice should be recommended whenever feasible.

The fifth approach, cultural control, or cultural practices for disease management, has traditionally been used by farmers in developing countries.

Suggested Citation:"Appendix F: Integrated Pest Management for Sustainability in Developing Countries." National Research Council. 1991. Toward Sustainability: A Plan for Collaborative Research on Agriculture and Natural Resource Management. Washington, DC: The National Academies Press. doi: 10.17226/1822.
×

Little information is available in an easily accessible or understandable form, however, on the best cultural practices used in traditional systems for disease control. Among the cultural practices used by traditional farmers are altering of crop and plant architecture, encouragement of biological control agents, burning, adjusting crop density or depth at time of planting, planting diverse crops, fallowing, flooding, mulching, multiple cropping, planting without tillage, using organic amendments, planting in raised beds, rotation, sanitation, manipulating shade, and tillage. Most, but not all, of these practices are sustainable.

Examples of Successful Integrated Disease Management

Successful integrated management programs have been developed for a number of diseases important in modern agricultural systems. Many diseases, however, are still controlled by a single disease management practice. Maize provides an example of successful integrated disease management. Maize varieties in the United States are controlled through the use of disease-resistant varieties and sound crop management practices involving crop rotation, plowing under contaminated crop debris, and selecting optimal planting dates, planting sites, and plant populations. Chemicals play a minor role in the management of maize diseases, but seed is often treated with fungicides. For alfalfa and soybeans, Phytophthora root rots are managed by a combination of resistant varieties, plowing under contaminated crop debris, field drainage, and site selection. Increasingly, integrated disease management is relying on a combination of host plant resistance and cultural practices and less on various pesticides used for pathogen control.

Integrated Weed Management

Successful integrated weed management as practiced by farmers relies heavily on cultural practices that keep pressure to a minimum, combined with mulching or mechanical tillage during the first four to eight weeks of crop growth, which allows the crop to get ahead of weeds that emerge later. This head start allows crops to compete effectively with weeds, primarily through shading. The period soon after crop emergence is called the “critical weed-free period,” and most weeds that emerge after this period do not affect crop yield, as determined by numerous experiments (Radosevich and Holt, 1984; Zimdahl, 1980). If weeds are a problem during this period despite control efforts, biological control agents and chemical control are options within an integrated weed management approach. Use of all cultural, biological, and chemical control measures should be considered carefully, however, for their effect not only on the target weed and the crop, but also on the environment and on invertebrates, nematodes, and microbes in the agroecosystem.

Suggested Citation:"Appendix F: Integrated Pest Management for Sustainability in Developing Countries." National Research Council. 1991. Toward Sustainability: A Plan for Collaborative Research on Agriculture and Natural Resource Management. Washington, DC: The National Academies Press. doi: 10.17226/1822.
×
Cultural Control

Cultural control techniques to minimize weed pressure include many of the same approaches used by farmers to control invertebrate pests and pathogens. These include crop rotations to interrupt weed life cycles, fallowing, burning, flooding, plant date selection, adjusting crop density and planting pattern to shade weeds, multiple cropping, and the use of clean seed. In addition, crop varieties can be chosen that are especially competitive with weeds. Research has shown that varieties that are tall, have a high leaf area index, or rapid leaf area accumulation early in the growing season can suppress weeds better than varieties of similar yield potential but different morphology. However, crops have not been screened specifically for “resistance ” to weeds in the way they are screened for insect and pathogen resistance or tolerance.

Cultural practices are considered the first line of defense against weeds, although many are abandoned by farmers who adopt a herbicide program for weed control. The cultural practices noted above should all be considered as components of a sustainable cropping system.

Mechanical Control

Tillage operations for mechanical control include primary tillage, secondary tillage, selective tillage and/or hand weeding, and tillage during a fallow period. Grazing, mowing, flame weeding, and soil solarization are other mechanical or physical options for weed control in some cropping systems.

Primary tillage turns under last season's crop residues and weed seeds. Secondary tillage, if delayed for two or more weeks after primary tillage, can destroy newly emerged weeds and create a relatively clean seed bed for the crop. Selective tillage includes rotary hoeing, cultivation between crop rows, hand hoeing, and hand weeding—all operations specifically performed for weed control. Repeated tillage during a fallow period is sometimes used to deplete the root reserves of a perennial weed. Grazing and mowing, in particular their timing, can be used for weed control in rangeland and forage crop systems. Flame weeding has been shown to be particularly effective for small-seeded crops (for example, carrots) and soil solarization, or heating through the use of a clear plastic mulch, has been used successfully for the production of high-value crops.

Any mechanical weed control practice used should be evaluated for its short-term and long-term environmental consequences. Primary tillage disrupts the life cycle of many soil organisms, in particular earthworms. Secondary tillage and selective tillage leave the soil relatively bare and loose during the first few weeks of the growing season and, thus, subject to

Suggested Citation:"Appendix F: Integrated Pest Management for Sustainability in Developing Countries." National Research Council. 1991. Toward Sustainability: A Plan for Collaborative Research on Agriculture and Natural Resource Management. Washington, DC: The National Academies Press. doi: 10.17226/1822.
×

erosion. The soil is probably no more vulnerable, however, than soil left bare through the use of herbicides. Tillage during a fallow period results in similar vulnerability, only for a longer period of time. Mowing and grazing of weeds in forage mixtures disrupts the habitat of invertebrates and microbes on the weeds or crops, although simply harvesting the crops would also cause this disruption. Timing of the disruption should be checked for its effect on the life cycle of beneficial insects in particular. Flame weeding requires the use of some fossil fuel and heats the soil surface slightly during the flaming operation. Flame-weeded crops also result in bare soil during a portion of the growing season. Soil solarization to kill weed seeds also kills or reduces the populations of microbes and invertebrates living in the upper horizons of the soil profile.

Cover Crops and Mulches

Mulch crops can be used in four ways for weed suppression, as cover crops in the rotation, live mulch crops, dead mulches, and allelopathic mulches.

Cover crops in rotation keep the soil covered and eliminate open “niches” of resource availability during which weeds can become established. A live mulch crop may be a cover crop that is allowed to remain in the field or is planted into the main production crop, which results in an intercrop, generally a relay crop system. Examples include maize strip-till planted into a clover and legumes or grasses that are intersown into maize at the final cultivation. A dead mulch system is one in which the main crop is planted into a standing mulch crop, which is then killed mechanically or chemically. Examples include the tapado system of Central America, in which beans are broadcast seeded into weeds, and then the weeds are mown or cut as a mulch. In the United States, winter annual cover crops, like hairy vetch, can be used for no-till corn production. Corn is slot-drilled into the hairy vetch, which is then killed by mowing, and left on the field to suppress weeds and supply nitrogen. Allelopathic mulches include cover crops in the first three categories that suppress weeds through chemical inhibition, in addition to physical effects. Well-known allelopathic cover crops in which the suppressive compounds have been identified include winter rye grain and oats.

Biological Control

Biological control of weeds through the introduction of insect pests and pathogens specific to particular species of weeds has been successful in many situations, for both annual and perennial weeds (Charudattan and Walker, 1982; Rosenthal et al., 1984). Unfortunately, these weed controls are often so specific and effective that private companies are not willing to

Suggested Citation:"Appendix F: Integrated Pest Management for Sustainability in Developing Countries." National Research Council. 1991. Toward Sustainability: A Plan for Collaborative Research on Agriculture and Natural Resource Management. Washington, DC: The National Academies Press. doi: 10.17226/1822.
×

develop or market them as control agents. Nonetheless, they hold promise for particular weed problems that may be encountered in a wide range of ecosystems, if developed and made available by a governmental or non-profit agency.

Chemical Control

Herbicides account for 42 percent of the world's pesticide sales and 49 percent of global pesticide use (kilograms/hectare) (Agency for International Development, 1990). Following the models of successful IPM insect control programs, weed researchers have been attempting to reduce herbicide use by determining economic thresholds for herbicides. The ready availability of postemergence herbicides makes this approach possible. Weed seedlings (or in some cases seeds) are counted, and based on models or previous experiments to determine the level at which yield loss will occur, herbicide treatments may be recommended. This approach has some inherent problems, however, principally involving time and labor.

The “monitor-and-spray-if-above-threshold” version of IPM can be used together with cultural and biological weed control practices to control problem weeds that are not effectively suppressed through other means—if one is confident about being able to predict when weeds are above the economic threshold, and if the appropriate herbicides are available at the right time and can be applied properly. It may be expensive to keep herbicides on hand if they are not used frequently. A major problem is the lack of ability to predict when yield loss will actually occur based on early-season weed counts. The effect of various weed species on soybean yield has been determined in the United States under controlled conditions, and those data can be used in predictive models. In the field, however, weeds occur in complex mixtures or communities and are often patchy, so even the most carefully developed model may be inaccurate under conditions that are less than uniform. Environmental conditions and soil fertility status also change the degree to which weeds and crops compete for limited resources, that is, more weeds can be tolerated without yield loss in a wet year compared with a dry year. Thus, models used to predict yield loss due to early-season weed presence should incorporate some form of weather forecast.

An integrated approach to weed management should take into account the effect of weeds and weed control practices on other components of the cropping system. The presence of weeds at certain levels may enhance insect pest control by providing habitat and/or an alternative food sources for beneficial insects. The removal of weeds through the use of herbicides, even if applied within an IPM framework, could disrupt the life cycles of beneficial insects.

Suggested Citation:"Appendix F: Integrated Pest Management for Sustainability in Developing Countries." National Research Council. 1991. Toward Sustainability: A Plan for Collaborative Research on Agriculture and Natural Resource Management. Washington, DC: The National Academies Press. doi: 10.17226/1822.
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An Example of Integrated Weed Control

Maize provides an example of integrated weed control. Maize, to begin with, should follow a previous crop with a different life cycle or growth habit—bush fallow in the tropics, for example, or winter wheat in a temperate climate. Mechanical means, such as burning or tillage in the tropic and moldboard or chisel plowing in temperate regions, are used to prepare the field prior to planting. These practices destroy or set back perennial weeds, and recently deposited weed seeds are burned or buried at a depth from which they cannot emerge if they germinate. Second, shallow tillage prior to planting can eliminate early-season weeds that germinate, and a delayed planting date in temperate climates allows the soil to warm up, which leads to rapid crop emergence and growth. During, and immediately after crop emergence, shallow mechanized tillage operations, such as rotary hoeing or harrowing, can be performed, followed by one or more passes with a row crop cultivator. Hand hoeing should be done at this time, supplemented by hand weeding in nonmechanized systems. For both the mechanized and nonmechanized cropping systems, timeliness of weed removal is essential at this stage.

During the rapid growth phase of maize, competition from the crop is important for effective weed suppression. In temperate, mechanized systems, high population densities combined with vigorous, high-leaf-area, high-yielding varieties are common. In tropical systems, it may be more common for lower population densities of maize to be combined with one or more intercropped food crops, (for example, beans, squash) to achieve a high leaf area index. Near the end of the maize life cycle, a cover crop can be undersown (for example, clovers or vetches in North America, Mucuna deeringiana and Dolichos lablab in the tropics) to provide competition for late-season weeds and fertility for the next crop in the rotation.

Management of Vertebrate Pests

Considerable crop losses are caused by birds and mammals, such as by rabbits on field crops and by rodents during postharvest storage of crops. Current control measure are primitive and ineffective, and attempts to control rodents in postharvest storage often lead to contaminated food. Few attempts have been made to develop any form of integrated management of such pest problems. There is an urgent need for innovative control measures.

THE INTEGRATION OF ARTHROPOD, NEMATODE, DISEASE, AND WEED MANAGEMENT

The main shortcoming in the development of IPM for many crops has been the failure to implement truly integrated control programs wherein

Suggested Citation:"Appendix F: Integrated Pest Management for Sustainability in Developing Countries." National Research Council. 1991. Toward Sustainability: A Plan for Collaborative Research on Agriculture and Natural Resource Management. Washington, DC: The National Academies Press. doi: 10.17226/1822.
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entomologists, plant pathologists, nematologists, and weed specialists work together and with agronomists and plant breeders as appropriate. Only such an interdisciplinary effort can produce a sound integrated crop protection program that provides protection against animal pests, diseases, and weeds using all available environmentally desirable means, including manipulation of farm practices, and as little of chemical pesticides as possible.

Most agricultural scientists are trained in particular disciplines and tend to think in a disciplinary pattern. Pesticides to control arthropods, nematodes, diseases, and weeds are applied based on recommendations of entomologists, nematologists, plant pathologists, and weed scientists. Even when applied with reference to IPM principles, the methods consider the pests in isolation; little consideration is given to the effect of pesticides on other organisms in the agroecosystem. The main inputs to crop production—fertilizers, cultivations, and cropping patterns —all have major effects on biological and cultural pest control as well as the effectiveness of pesticides.

Arthropod pests, nematodes, plant pathogens, and weeds all interact strongly with each other, and their interactions must be taken into account in the planning of integrated crop protection programs. There are many examples of such interactions, some well documented, others more speculative. A number of the interactions are highlighted below.

  • Insects transmit viruses, bacterial diseases, and fungi (for example, Dutch elm disease), along with other arthropods; feed on bacteria and fungi, including pathogens; attack weeds and weed seeds; and prey on nematodes and their cysts.

  • Weeds can be alternative hosts for nematodes, arthropod pests, and diseases; can provide shelter for arthropod pests and their enemies; can attract or repel arthropod pests; can cause nematode cysts to hatch; can provide ground cover that favors carryover of diseases; and can be the overwintering hosts for arthropod pests.

  • Pathogens can attack insects and weeds, can overwinter on weeds, and can influence the severity of other pathogens.

In addition, pesticides interact with natural pest control agents, as outlined below.

  • Insecticides kill natural enemies of arthropod pests and nematodes, kill insects that feed on weeds, and kill arthropods that feed on fungi and other pathogens.

  • Fungicides kill pathogens of pest insects and weeds, kill fungi that are the main natural control agents of nematodes, and kill organisms that are antagonistic to pathogens.

  • Herbicides can kill arthropods and remove food of natural enemies.

Suggested Citation:"Appendix F: Integrated Pest Management for Sustainability in Developing Countries." National Research Council. 1991. Toward Sustainability: A Plan for Collaborative Research on Agriculture and Natural Resource Management. Washington, DC: The National Academies Press. doi: 10.17226/1822.
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All farm practices also exert an influence on the incidence of arthropod-pests, diseases, and weeds (Edwards, 1989).

  • Inorganic fertilizers influence the growth of weeds, as well as crops, when broadcast; can make plants more susceptible to pathogens and increase disease incidence; can make plants more susceptible to arthropod pests; and can affect soil acidity-alkalinity, which in turn affects pathogens and the beneficial microflora in the soil.

  • Organic fertilizers can decrease arthropod pest and disease incidence by increasing species diversity in favor of natural enemies, can absorb and inactivate pesticides, can provide alternative food for marginal arthropod pests, and can promote growth of fungi that control cysts and other nematodes.

  • Cultivations mix pesticides into soil and bring them into contact with pests, affect the incidence of arthropod pests and diseases, increase the persistence of pesticides in soil, affect the natural enemies of arthropod pests, influence the distribution of pathogens in soils, and affect the incidence of weeds by mechanical damage by burying and bringing up weed seeds.

  • Rotations decrease the incidence of arthropod pests by affecting the carryover from susceptible crops to another susceptible crop the following year, decrease the incidence of pathogens related to particular crops, minimize nematode populations, decrease weed problems, and encourage the buildup of natural enemies of arthropod pests.

  • Cropping patterns provide physical barriers to movement of pests, provide an altered microclimate, and transmit diseases (Allen, 1989), and intercropping and undersowing favor natural enemies of arthropod pests, provide more competition to weeds than monocultures, and decrease attack by some pathogens.

The only way to identify the key inputs in an integrated pest, disease, and weed management program is through the development of a thorough information base and additional research on critical components. Finally, a practical model must be developed that can be tested for its effectiveness in the field. Such tests should be made in a whole farm system rather than in experimental field plots. The additional benefit of this on-farm approach is that it provides the farmer with knowledge of the relevant techniques on his or her own farm and serves as a demonstration area for neighboring farmers, thus filling an extension as well as a research role.

Integrated pest management and integrated farming systems are much more knowledge- and management-intensive than the simple use of pesticides and fertilizers on a recommended basis. They should be based on a firm understanding of the factors that exert the greatest effect on pests. Nevertheless, IPM systems can be developed progressively from a relatively simple pattern, adding components as the system and its interactions

Suggested Citation:"Appendix F: Integrated Pest Management for Sustainability in Developing Countries." National Research Council. 1991. Toward Sustainability: A Plan for Collaborative Research on Agriculture and Natural Resource Management. Washington, DC: The National Academies Press. doi: 10.17226/1822.
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become progressively better understood. In this way the chemical inputs can be decreased progressively.

Because IPM is complex, thorough training must be provided for extension agents and farmers. For agents and farmers in developing countries, such training can be provided by bringing personnel to the United States or Europe for workshops or courses. Alternatively, it can be achieved by sending consultants to the developing countries.

THE RELATIONSHIP OF IPM TO SUSTAINABLE AGRICULTURE

The idea that pest management should be considered in the context of farm management was proposed by Vereijken et al. (1986). They suggested that a farming system consists of five main components: cultivations, fertilization, cropping patterns, crop protection, and farm economics. Central to this pattern is farm economics, which encompasses all inputs, including land, labor, buildings, machines, chemicals, and seed, balanced against yield and profits. A farming system is not just the sum of all of its components, but a complex system with intricate interactions. The concept of the central position of farm economics is in striking contrast to the perception of integrated control specialists who have assumed that plant protection, or their particular discipline, is the central component. Crop protection is only one important part of the system, and its needs and implementation depend on the system and the importance of pests.

As outlined in the previous section, crop protection measures, whether chemical or biological, all interact strongly with cultivations, fertilizers, and cropping patterns. Only in a system that minimizes chemical use, as proposed in sustainable agriculture, can undesirable ecological and environmental effects, such as pollution of soil and water by pesticides, be truly minimized. In general, integrated farming takes into account, far more than does conventional farming with standard pesticide use, the various impacts on ecosystems and society. It considers effects on (a) the quality and quantity of produce, (b) the economic viability of the system, (c) employment, public health, and the well-being of people associated with agriculture, (d) needs for energy and nonrenewable resources, (e) the quality and diversity of the landscape (clean environment), and (f) the preservation of the fauna and flora.

Currently, the conventional approach to crop production has (a) and (b) as its main objectives, and it does not take the other aspects sufficiently into account, the results of which have sometimes been undesirable or even harmful. In recent years, there have been increasing demands for a better balance among the various factors, based on a growing awareness of the problems caused by conventional, chemically based farming. Hence, the increasing need for an integrated, sustainable farming systems approach.

Suggested Citation:"Appendix F: Integrated Pest Management for Sustainability in Developing Countries." National Research Council. 1991. Toward Sustainability: A Plan for Collaborative Research on Agriculture and Natural Resource Management. Washington, DC: The National Academies Press. doi: 10.17226/1822.
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The Impact of Innovative Practices on Pest Management

Traditional agriculture in temperate countries has depended on deep plowing, the use of inorganic fertilizers and chemical pesticides in large fields, and growing crops in monoculture or biculture. Such practices encourage the carryover of pests, diseases, and weeds from one year to the next by minimizing overall diversity and disturbance. All of the basic components can be modified by introducing newer practices that decrease the adverse effects of pests and reduce the need for pesticides. In developing countries, the Green Revolution has encouraged a similar pattern of agriculture. In poorer soils, pest, disease, and weed control depends only on the use of cropping patterns and cultivations.

Mechanical Operations and Cultivations

Traditionally, moldboard plowing inverted the soil and buried crop residues and weeds before the preparation of a seed bed for the succeeding crop. Since the 1960s, there has been a trend toward less and shallower tillage, which has culminated in the practice of killing the previous crop with herbicides and planting the next crop directly into the plant residues. This practice requires considerable use of herbicides, but current research is examining how it can be accomplished with minimal use of herbicides. No-till farming, as it has been termed, usually involves the use of special machinery. The changes in soil displacement and disturbance, location of plant residues, and weed ecology all influence the incidence of arthropod pests and diseases. Conservation tillage leads to a completely different spectrum of weeds, with lower populations of species that need to have their seeds buried to germinate and higher populations of species that are controlled by cultivation. Similarly, some diseases and insect pests decrease in severity with less cultivations and others increase. Of 45 studies surveyed by Stinner and House (1990), which involved 51 arthropod pest species, the damage by 28 percent of the pest species increased with decreasing tillage, damage by 29 percent was not significantly affected by tillage, and damage by 43 percent decreased with decreasing tillage. Thus, tillage plays a major role in pest incidence and should be taken into account in designing farm management systems that maximize pest control.

Nutrient Supply and Fertilizer

There is good evidence that inorganic fertilizers can increase pest attack and the need for use of pesticides. When inorganic fertilizers are broadcast over a field, they promote weed growth between the crop rows and increase the need for herbicides, whereas placement of the fertilizer in the row would

Suggested Citation:"Appendix F: Integrated Pest Management for Sustainability in Developing Countries." National Research Council. 1991. Toward Sustainability: A Plan for Collaborative Research on Agriculture and Natural Resource Management. Washington, DC: The National Academies Press. doi: 10.17226/1822.
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minimize this effect (Edwards, 1989). Inorganic fertilizers can increase the incidence of leaf diseases, such as cereal leaf disease (Jenkyn and Finney, 1981), and they can also increase the incidence of pests, such as cereal aphids. Using minimal amounts of inorganic fertilizers lessens the susceptibility of crops to pests.

Organic fertilizers, on the other hand, tend to decrease attacks by diseases (Hoitink and Fahy, 1986) by promoting the activity of fungal antagonists. They also decrease attacks by many invertebrate pests by increasing species diversity in favor of natural enemies (Altieri, 1985; Edwards, 1989), by providing alternative food for marginal pests, by promoting the activity of pest antagonists, such as fungi, that attack nematodes (Kerry, 1988) and other pests, and by building up populations of arthropod predators of pests by providing them with alternative food sources. Organic matter also facilitates cultivation for control of weeds. Thus, addition of organic matter minimizes pest problems.

Biodiversity and Cropping Patterns

In temperate countries, the trend has been to grow crops in monoculture or biculture over extended periods. Multiple cropping, that is, growing more than one crop in a single field, was common in earlier agriculture and is still the main pattern in many tropical countries. Multiple cropping systems, however, are much less common, even in developing countries, than they once were.

Multiple cropping includes traditional annual sequential cropping or crop rotations, but also such innovative practices as growing two crops in the same field in a single season; intercropping or undersowing, that is, growing two or more crops in the same field, usually in alternate rows; and strip cropping, that is, growing two crops in strips wide enough to allow independent cultivation and treatments but narrow enough to allow ecological interaction (Francis, 1986). All such multiple cropping systems increase the biodiversity of habitat structure and species, which tends to minimize the incidence of pests, diseases, and weeds (Stinner and Blair, 1989). Such innovative cropping patterns have considerable potential for incorporation into integrated, lower-chemical-input farming systems in developing countries.

Integration of Farming Practices and Pest Management

Much is known about how some agricultural practices affect pest management (Edwards, 1989). Much more information is needed, however, on how the more innovative practices interact with pest attacks so that the best of them can be adopted. In addition, the principles of IPM programs must be extended to cover whole farming systems, and in a way that involves

Suggested Citation:"Appendix F: Integrated Pest Management for Sustainability in Developing Countries." National Research Council. 1991. Toward Sustainability: A Plan for Collaborative Research on Agriculture and Natural Resource Management. Washington, DC: The National Academies Press. doi: 10.17226/1822.
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minimal use of agrochemicals and maximum use of cultural practices. Some efforts have been made to develop simple simulation models that can provide recommendations on integrated pest management and farming systems based on simple, user friendly, question-and-answer systems (Willson et al., 1987).

Integrated sustainable farming systems of the kind proposed could have a number of important benefits. In particular, they could maximize profits by lowering expenditures on purchased chemicals such as pesticides; minimize food contamination by pesticides; decelerate the development of pest resistance to chemicals; reduce the environmental impact of pesticides on beneficial organisms and wildlife; decrease the hazards to farmers of pesticide application; and minimize soil erosion.

CONSTRAINTS TO THE ADOPTION OF INTEGRATED PEST MANAGEMENT IN DEVELOPING COUNTRIES

Education

A major constraint to the successful implementation of IPM, especially in developing countries, is a lack of knowledge about IPM at all levels. Farmers, agribusiness personnel, politicians, policymakers, the general public, researchers, extensionists, and teachers—all should be better informed about the values, strategies, and results of IPM. The level of education in developing countries varies greatly, but education on pests and pest management is generally lacking or inadequate, even though the major national activity may be agriculture and pests a limiting factor.

In developing countries, extension is usually weak and poorly supported, and extension personnel usually have very low rewards and prestige. Often, the sheer number of farmers needing service is overwhelming, and thus larger farmers are given priority. Generally, extension programs have low funding, inadequate transportation, and poorly trained personnel. They have little to offer farmers and thus have little or no impact on farming practices. IPM specialists are few in number or unknown in most developing countries. If government decision makers and policymakers could be influenced to give adequate support and training to extension personnel, and if IPM specialists could be trained and adequately supported, the benefits to the agriculture of developing countries would be economic, substantial, and long lasting.

Economic and Social Constraints

The high cost of pesticides in developing countries seriously limits their use. Few farmers can afford to use them even if they are available. In

Suggested Citation:"Appendix F: Integrated Pest Management for Sustainability in Developing Countries." National Research Council. 1991. Toward Sustainability: A Plan for Collaborative Research on Agriculture and Natural Resource Management. Washington, DC: The National Academies Press. doi: 10.17226/1822.
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those cases where no other management tactic is available for pest management, and pesticides are needed or appropriate, their high cost and unavailability constitute serious constraints to crop production. Knowledge of IPM technology cannot be delivered without some social and economic costs as well. Even when outside agencies cooperate in the development of IPM programs in developing countries, there is considerable cost to national governments. In today's world, crushing debt and the rising costs of petroleum energy have made it difficult for many developing countries to initiate new programs and to support their existing programs. These realities make the initiation of new IPM programs and training especially difficult.

The rapid expansion in the use of synthetic organic pesticides in developed countries after World War II meant that it was possible to produce blemish-free fruits and vegetables. Regulatory agencies set strict tolerances for contaminating insect parts in processed food. These high standards are primarily for aesthetic purposes and are not essential to the production of healthful food. When such strict standards spread to developing countries, they become a major constraint to the development of IPM, especially when agricultural products are produced for export to developed countries.

Environmental Problems

Pesticides are often considered to be a rapid and efficient solution to many serious pest problems in developing countries in the short term. For the long term, however, the well-known problems of resistance to pesticides, pest resurgence, secondary pest outbreaks, environmental contamination, and toxicological problems from pesticides make their use expensive and economically and socially unacceptable. Overuse and misuse of pesticides are often serious constraints to the implementation of IPM in developing countries (Edwards, 1973a,b; Edwards et al., 1978).

Historically, many sustainable agricultural systems, such as some of those in China, depended on the incorporation of large quantities of organic matter into soil. This generally resulted in reduced soil-borne disease and nematode and insect attacks, in addition to providing other important agronomic benefits. The poor availability of organic amendments in modern agricultural systems, however, is a constraint on the improvement of overall soil fertility and the control of soil-borne plant pests and pathogens. Before World War II, most agriculture in the corn belt of the United States involved both crops and livestock. Rotations were on 3- to 6-year cycles, animal manure was applied to the soil, and rotations usually included legumes. That system has given way to cash-grain systems in which rotations, if practiced, are of short duration and most fertilizers are inorganic. The cash-grain system is not a sustainable model in the long term and is inappropriate for most developing countries. Declining use of organic amend-

Suggested Citation:"Appendix F: Integrated Pest Management for Sustainability in Developing Countries." National Research Council. 1991. Toward Sustainability: A Plan for Collaborative Research on Agriculture and Natural Resource Management. Washington, DC: The National Academies Press. doi: 10.17226/1822.
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ments in agriculture is a serious constraint to the control of soil-borne pests and pathogens and to long-term sustainable agriculture, in both developed and developing countries.

Policy Constraints

Especially during the past decade, actions by monetary authorities in developing countries have been raising rates of interest, including those paid by the government, to unprecedentedly high levels. The need to pay off debts at high interest rates means that governments demand immediate financial resources, such as taxes, from farmers, and both farmers and governments find it difficult to consider long-run, environmentally sound agricultural practices. The various lenders, such as the commercial banks, the World Bank, and the International Monetary Fund, must re-examine their fiscal policies if they wish to encourage sound, sustainable agriculture in developing countries.

The governments of developing countries have been adopting domestic farm policies, such as agricultural subsidies, that often depress and destabilize world prices for many of the agricultural products from developing countries. Unless developing countries receive a fair price for their agricultural products, they cannot afford to initiate IPM programs and educate and train farmers and technical personnel. Thus, the policies of developing countries are also a serious constraint to the initiation of IPM programs and long-term sustainable agriculture.

Energy

There are many concerns today about conventional agricultural systems that are highly energy intensive and built on a narrow genetic base, that emphasize increasingly high yields, and that lead to monoculture and sometimes to excessive erosion, pollution, and contamination by pesticide residues. Probably the most serious of these concerns is the dependence on fossil-fuel energy in modern agriculture. Petroleum is used to manufacture almost all pesticides, to manufacture fertilizers, to produce agricultural machinery, to fuel the machinery and irrigation equipment, and to process and distribute food and fiber. Petroleum is a nonrenewable, finite resource. As the price of petroleum and its products increases, reliance on petroleum energy becomes a serious constraint to the use of some IPM strategies, particularly in developing countries.

Research and Extension Support

In general, the support of research and extension activities by national governments in developing countries is minuscule. Research and extension

Suggested Citation:"Appendix F: Integrated Pest Management for Sustainability in Developing Countries." National Research Council. 1991. Toward Sustainability: A Plan for Collaborative Research on Agriculture and Natural Resource Management. Washington, DC: The National Academies Press. doi: 10.17226/1822.
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activities are not only poorly supported, but separate and competing. For example, only 0.26 percent of the Costa Rican national budget went to agricultural research and 0.34 percent went to agricultural extension (Stewart, 1985). Yet, the main source of foreign exchange in Costa Rica is agriculture.

REFERENCES

Agency for International Development. 1990. Reports to the United States Congress by the Agency for International Development. I. Integrated Pest Management: AID Policy and Implementation. II. Pesticide And Poisoning: A Global View. Washington, D.C.: Agency for International Development.

Allen, D. J. 1989. The influence of intercropping with cereals on disease development in legumes. Paper prepared for CIMMYT/CIAT Workshop on Research Methods for Cereal/ Legume Intercropping in Eastern and Southern Africa, Centro International de Agricultura Tropical (CIAT) Regional Bean Program, Arusha, Tanzania

Altieri, M. A. 1985. Diversification of agricultural landscapes—A vital dement for pest control in sustainable agriculture. Pp. 124–136in Sustainable Agriculture and Integrated Farming Systems, T. C. Edens C. Fridge and S. L. Battenfield eds. East Lansing: Michigan State University.

Charudattan, R., and H. L. Walker. 1982. Biological Control of Weeds with Plant Pathogens. New York: John Wiley & Sons.

Edwards, C. A. 1973a. Environmental Pollution by Pesticides. New York: Plenum Press.

Edwards, C. A. 1973b. Persistent Pesticides in the Environment, 2d ed. Cleveland: CRC Press.

Edwards, C. A. 1989. The importance of integration in sustainable agricultural systems Ecosystems and Environment 21:25–351.

Edwards, C. A., and J. Oswald. 1981. Control of soil-inhabiting arthropods with Neoaplectana carpocapsae Proceedings 11th British Insecticides and Fungicides Conference (2):467–473.

Edwards, C. A., G. K. Veeresh, and H. R. Krueger. 1978. Pesticide Residues in the Environment in India. Bangalore, India: Raja Power Press.

Food and Agriculture Organization. 1967. Report of the First Session of the FAO Panel of Experts on Integrated Pest Control. Rome, Italy: Food and Agriculture Organization of the United Nations.

Francis, C. A. ed. 1986. Multiple Cropping Systems. New York: Macmillan.

Hoitink, H. A. J., and P. C. Fahy. 1986. Basis for the control of soil-borne plant pathogens with composts Annual Review of Phytopathology 24:93–114.

Jenkyn, J. F., and M. E. Finney. 1981. Fertilizers, fungicides and sowing date. Pp. 179–188in Strategies for the Control of Cereal Diseases, J. F. Jenkyn and R. T. Plumb eds. Oxford, England: Blackwell.

Kerry, B. 1988. Fungal parasites of crop cyst nematodes. Pp. 293–306in Biological Interactions in Soil, C. A. Edwards et al. eds. The Hague, Netherlands: Elsevier.

Norton, G. A., and C. S. Holling. 1979. Proceedings of an International Conference on Pest Management, October 25–29, 1976. New York: Pergamon Press.

Office of Technology Assessment, U.S. Congress. 1990. A Plague of Locusts, Special Report. OTA-F-450. Washington, D.C.: U.S. Government Printing Office.

Suggested Citation:"Appendix F: Integrated Pest Management for Sustainability in Developing Countries." National Research Council. 1991. Toward Sustainability: A Plan for Collaborative Research on Agriculture and Natural Resource Management. Washington, DC: The National Academies Press. doi: 10.17226/1822.
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Radosevich, S. R., and J. S. Holt. 1984. Weed Ecology: Implications for Vegetation Management. New York: John Wiley & Sons.

Rosado-May, F. J., R. Garcia-Espinosa, and S. R. Gliessman. 1985. Impacto de los fitopatogenos del suelo al cultivo del frijol en suelos bajo differente manejo en la Chontalpa Tabasco. Revista Mexico Fitopatologia 3(2):80–90.

Rosenthal, S. S., D. M. Maddox, and K. Brunetti. 1984. Biological Methods of Weed Control. Monograph for the California Weed Conference. Fresno, Calif.: Thomson Publications.

Smith, R. F., and H. T. Reynolds. 1965. Principles, definitions and scope of integrated pest control. Proceedings of FAO Symposium on Integrated Pest Control 1:11–17.

Stern, V. M., R. F. Smith, R. van den Bosch, and K. S. Hagen. 1959. The integrated control concept. Hilgardia 29:81–101.

Stewart, R. 1985. Costa Rica and the CGIAR Centers. A Study of Their Collaboration in Agricultural Research. Consultative Group on International Agricultural Research, Study Paper No. 4. Washington, D.C.: World Bank.

Stinner, B. R., and J. M. Blair. 1989. Ecological and agronomic characteristics of innovative cropping systems Pp. 123–140in Sustainable Agricultural Systems, C. A. Edwards et al. eds. Ankeny, Iowa: Soil and Water Conservation Society.

Stinner, B. R., and G. J. House. 1990. Arthropods and other invertebrates in conservation tillage agriculture Annual Review of Entomology 35:299–318.

Vereijken, P., C. A. Edwards, A. El Titi, A. Fougeroux, and M. J. Way. 1986. Management of Farming Systems for Integrated Control WPRS 1986 (IX) 2. Bulletin of the International Organization for Integrated Control

Willson, H., F. Hall, J. Lennon, and R. Funt. 1987. Market Model: A Decision Support Program from the Computer Advisor System for Horticulture (CASH). Columbus: Ohio State University.

Zimdahl, R. L. 1980. Weed-Crop Competition: A Review. International Plant Protection Center. Corvallis: Oregon State University.

Suggested Citation:"Appendix F: Integrated Pest Management for Sustainability in Developing Countries." National Research Council. 1991. Toward Sustainability: A Plan for Collaborative Research on Agriculture and Natural Resource Management. Washington, DC: The National Academies Press. doi: 10.17226/1822.
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Suggested Citation:"Appendix F: Integrated Pest Management for Sustainability in Developing Countries." National Research Council. 1991. Toward Sustainability: A Plan for Collaborative Research on Agriculture and Natural Resource Management. Washington, DC: The National Academies Press. doi: 10.17226/1822.
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Page 126
Suggested Citation:"Appendix F: Integrated Pest Management for Sustainability in Developing Countries." National Research Council. 1991. Toward Sustainability: A Plan for Collaborative Research on Agriculture and Natural Resource Management. Washington, DC: The National Academies Press. doi: 10.17226/1822.
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Page 127
Suggested Citation:"Appendix F: Integrated Pest Management for Sustainability in Developing Countries." National Research Council. 1991. Toward Sustainability: A Plan for Collaborative Research on Agriculture and Natural Resource Management. Washington, DC: The National Academies Press. doi: 10.17226/1822.
×
Page 128
Suggested Citation:"Appendix F: Integrated Pest Management for Sustainability in Developing Countries." National Research Council. 1991. Toward Sustainability: A Plan for Collaborative Research on Agriculture and Natural Resource Management. Washington, DC: The National Academies Press. doi: 10.17226/1822.
×
Page 129
Suggested Citation:"Appendix F: Integrated Pest Management for Sustainability in Developing Countries." National Research Council. 1991. Toward Sustainability: A Plan for Collaborative Research on Agriculture and Natural Resource Management. Washington, DC: The National Academies Press. doi: 10.17226/1822.
×
Page 130
Suggested Citation:"Appendix F: Integrated Pest Management for Sustainability in Developing Countries." National Research Council. 1991. Toward Sustainability: A Plan for Collaborative Research on Agriculture and Natural Resource Management. Washington, DC: The National Academies Press. doi: 10.17226/1822.
×
Page 131
Suggested Citation:"Appendix F: Integrated Pest Management for Sustainability in Developing Countries." National Research Council. 1991. Toward Sustainability: A Plan for Collaborative Research on Agriculture and Natural Resource Management. Washington, DC: The National Academies Press. doi: 10.17226/1822.
×
Page 132
Suggested Citation:"Appendix F: Integrated Pest Management for Sustainability in Developing Countries." National Research Council. 1991. Toward Sustainability: A Plan for Collaborative Research on Agriculture and Natural Resource Management. Washington, DC: The National Academies Press. doi: 10.17226/1822.
×
Page 133
Next: Appendix G: Project Bibliography »
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Toward Sustainability recommends a design for a new Collaborative Research Support Program (CRSP) for the U.S. Agency for International Development (AID). Currently, eight CRSPs operate under legislation that supports long-term agricultural research of benefit to developing countries and the United States.

This book defines a process by which knowledge from all relevant AID-supported programs could be integrated and applied to advance profitable farming systems that improve local conditions and contribute to environmental goals. It makes recommendations on the types of competitive grants that should be made available under a new program, institutional participation, content of research proposals, and administrative procedures.

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