In Vietnam, there was no significant difference in yield between EBRM and traditional
rodent management. However, there was a marked reduction in usage of rodenticides
(Table 1; Singleton et a!., zo03) and plastic fencing in villages that practised
EBRM. This provided environmental benefits as well as economic gains. A benefit-cost
analysis provided a positive benefit of EBRM because the costs for rodent control were
significantly reduced in the villages where EBRM was adopted (Brown et a!., zooS).
The benefit-cost ratio on untreated sites was around 3:1 each year, whereas on treated
sites the ratio increased from 3:1 at the beginning to 17:1 in the final year of the project.
This occurred through fewer farmers applying rodenticides (cost of US $5.71 per
hal and fewer farmers establishing plastic barrier fences to keep rodents out of their
fields (cost of US $12.50 per field per season) on treated sites.