The rat is the most important pest of rice in Cambodia. Rat problems are likely to get worse with increased cropping intensity. Farmers have traditionally managed rats in various ways e.g. using zinc phosphide bait, trapping, digging burrows, hunting, and plastic fences. Sometimes, this has been supported by a bounty on rat tails. There is scope to improve existing practices both by improving the techniques of rat management used by individual farmers and by greater attention to concerted action by communities. Previous work in Cambodia showed the usefulness of community-based approaches based on the concerted action of individuals pursuing their own practices and on novel technology (such as the active trap barrier system - TBS), and managing the latter as a community resource. TBS technology has been developed elsewhere in the region but the economic and social aspects of this technology are poorly understood.
Management of the TBS as a common property resource (i.e. at a community level) was tested as a means to overcome this problem. This also entailed melding together the technical aspects of the technology and the social arrangements that support it. An earlier ACIAR-funded rodent project advanced the knowledge of rodent pest ecology and control in Southeast Asia. This project built on this large ecological knowledge base.
The project investigated the technical, social and economic aspects of rodent pest management in Cambodia. Researchers identified appropriate social institutions for managing the trap barrier system as a common property resource at a village level, evaluated various technological options for improved rodent management in Cambodia, and promoted a greater familiarity with and acceptance by the Cambodian Agricultural Research and Development Institute of community-based approaches to technology development.
Researchers developed a rodent management plan and a monitoring plan. They trained farmers in management and monitoring methods and assisted with implementation at the selected sites. They oversaw the process and assisted with issues that arose in the course of implementation.
Throughout the project the evaluation focused on two areas: the methods for managing the rodent pests and the progressive institution of a community-based system of management. The researchers focused on the efficacy, including the economic costs, of respective management options, both in isolation and as part of the integrated program of community-based management.
ACIAR focused this project on the adoption of the community-based TBS and other rice field rodent pest control methods in Kampong Cham Province in Cambodia. The following extension material for community TBS was developed and used for training workshop and general distribution through the government network:
(1) a 36-page booklet entitled TBS for field rat management
(2) a 4-page pamphlet Wax block baiting technique to control rice field rat
(3) a 95-page book Rice field rats: biology, management, and case study in lowland field
(4) a 58-page book Participatory research and extensions manual for trainers and trainees
The extension material was produced in Khmer and distributed to researchers and extension workers in Cambodia through the government network.
A total of 33 community-based TBS's were implemented by 240 farmers during the project. The key findings of this study indicate that the adoption of the technology is limited because the cost of establishing and maintaining the community TBS is justified if rodent damage to crops is high and predictable. The community TBS must be implemented in the rice field at the transplanting stage so that a lure crop to attract rats is planted inside the TBS. Farmers cannot make a decision at the planting stage whether or not to implement a community TBS because it is too early to forecast rodent damage to crops at the transplanting stage.
However, a number of farmers at the project site adopted and improved the community TBS in areas where high rodent damage occurs regularly each year. The financial support from the project (e.g., supply of trap and fence materials) for the community TBS was gradually phased out from 40% of total cost in 2003 to 0% in 2004. The number of TBS groups, the number of participating farmers, and the quality of TBS construction and maintenance did not decline over this period, indicating that the community TBS is self sustainable.
The most commonly used method to control rice field rodents in Southeast Asia has been and will continue to be the application of rodenticide bait. This is because the bait has been the most affordable technology for rice farmers. Laying rodenticide bait is also the most commonly used method for the control of mouse plagues in Australia. Our project has conducted an experiment to demonstrate that bait uptake and palatability is improved by 65% by replacing maize with rice as the bait base. The farmers also learnt to make wax block bait with technical inputs from the project. They prefer to use wax block bait because they are weather-resistant and unpalatable to non-target species such as chickens, dogs and other domestic animals.
The participating farmers improved both the TBS and zinc phosphide baiting technologies. They played the role as trainers in workshops to teach other farmers to use these technologies. Although the primary aim of these workshops was to field-test the extension material developed by the project, the workshops did achieve extension of the technologies to farmers from nearby communes. However, the success of the extension was limited geographically because only farmers near the project site could attend the workshops. The project was not designed to extend the technologies beyond the study site.
Links:
[1] http://www.aciar.gov.au/country/Cambodia
[2] http://www.communityzero.com/camfarmers
[3] http://www.aciar.gov.au/programarea/Agricultural Development Policy