|Extension of Complex Issues - Success Factors in Integrated Pest Management (LBL - SKAT - SDC, 1997, 102 p.)|
IPM - the definition as perceived and used in the study
"IPM is a strategy that employs every acceptable economic, ecological and toxicological technique available to keep pest populations below economic thresholds This strategy purposely gives preference to the use of natural regulating mechanisms' (SDC 1994a)
Recent estimates show that world population will grow by another 5 thousand million during the 21st century, resulting in a more or less stable total population of 11.5 thousand million shortly after the year 2100. This population must be fed out of total crop areas that have little potential for expansion. This means that intensified production will be urgently needed, at a growth rate (according to FAO estimates) of 2 to 3 percent annually. While there are efforts to make available the genetic potential of underrated crops in many parts of the world, dependence on few high-yielding crop species will further increase. There is a positive correlation between yield potential and pest and disease susceptibility. This makes clear that pest management in support of reliable harvests will be essential instruments in ensuring the necessary growth in food production. Sustainable pest management is therefore to be set high on the agenda of projects contributing to the development of countries of the South. For environmental and economic reasons, this will necessarily be IPM.
Considering the substantial losses to agricultural produce caused by pests, it is not astonishing that crop protection has received a high level of attention, starting with farmers and national planners in developing countries and extending to the chemical industry. Many governments set up special Crop Protection Departments (e.g. Indonesia, India etc.) with a twofold duty, namely to forecast pest outbreaks and to advise farmers with regard to crop protection. The use of pesticides increased dramatically during the course of the Green Revolution. In the case of Indonesia it culminated in the Government placing chemical companies under contract to conduct aerial sprayings.
The concept of IPM would have already been familiar to some people even that long ago. In 1968, the FAO had published its definition of IPM as "a pest management system that, in the context of the associated environment and the population dynamics of the pest species, utilises all suitable techniques and methods in as compatible a manner as possible, and maintains the pest populations at levels below those causing economically unacceptable damage or loss" (FAO, 1968 quoted in: van de Fliert, in press). Until today, the concept of IPM is subject to differing interpretations, ranging from simple combinations of pesticides with other techniques to complex ecological habitat management strategies. Everybody involved in pest management, from pesticide dealers to ecologically motivated grass-roots NGOs, talks about IPM (compare SDC 1994a).
For the present study, the IPM definition used by SDC is our yardstick. It reads as in the box aside.
The second sentence of the above definition stresses the preference to be given to natural processes. Notably, SDC's definition differs from the IPM definition proposed by Ciba, which uses the following wording: IPM is "the farmer's best combination of cultural, biological and chemical measures that yield the most cost-effective, environmentally sound, and socially acceptable insect, disease and weed management for crops in a given situation" (Ciba 1996).
Farmers are scouting pests and beneficials in a rice field in China The understanding of a rice field as a whole system in which beneficials are able to control pests to a large extent is a cornerstone of IPM
Many IPM experts disagree with the involvement of chemical pesticides producers and their agents in the discussion of IPM issues and extension. Their point is that in the end such organisations will always and inevitably have a bias toward selling their products, and that therefore the agents of such companies are not truly competent in IPM. The study group does not see its task as being to decide whether this position is right or not. Its stand does not so much start out from a position as to which interpretation of "IPM" is preferred, than from one that looks at the degree of success in extension work, i.e. the communicative component. This way, some lessons may be learnt about what may make the extension models of the chemical industry successful.
A core principle used in IPM was the application of economic threshold levels (ETL): The application of a plant protection measure (mostly pesticides) was to take place only if the cost of the application were considered lower than the expected economic loss. Today this concept is a point of disagreement among many IPM experts because they question its usefulness and applicability. The assessment alone is a complex task even if many simplifying assumptions are made, which often means that they have to be determined and regularly updated by research facilities and then conveyed to comparatively large extension areas. Specific reasons voiced to question the concepts are
· prices of farm products and of pesticides fluctuate regionally, between seasons and even over the season
· the ETL concepts tend to disregard non-chemical and/or preventive measures in determining the treatment costs used for threshold assessment
· natural enemy populations and their dynamics are not considered in ETLs
· farmers include many other factors in crop protection decision making that are not considered in the ETL concepts
· over and above, the application of ETLs has been found to be impractical in daily farm management (van de Fliert 1996, personal communication).
Van de Fliert therefore advocates replacing the economic threshold with an "experience threshold" which would be developed by farmers themselves and which would be applicable under specific farm conditions.
ETLs are a concept that originate from a specific vision of pest management and pests. It is not the only vision possible, as the theses on the following pages will show. Whether to use it or not will depend much more on the setting, culture, pest, and capacities of involved institutions rather than on whether it can be applied in extension in a sensible way. But arguments for or against ETLs serve as an indicator to which vision or generation of IPM a particular project adheres,
IPM practices include a wide range of approaches. Some of these are not possible without very large and regionally or even internationally backed structures. The theses on the following pages do not apply to special situations such as solving pest problems by fully-fledged classical biological control (for example by the International Institute for Tropical Agriculture (IITA) on cassava in Africa), or to the problems of pests and diseases migrating over long distances, such as e.g. locusts in Africa, or a wide range of fungal, viral and bacterial diseases. For this study, we include only approaches to IPM which involve pest management problems realistically suited to be solved at the individual farm or community level. They are the vast majority.