Rat Control in Pineapples on Rota

SUMMARY
In the Commonwealth of the Northern Mariana Islands, three rodent species are responsible for damage to nearly crop grown, particularly high value crops like melons, sweet corn and pineapples. While standard rodenticides are available in most agricultural outlets, they are often too expensive and ineffective as rodents from residential areas continue to invade farmland. What’s more, the rats killed by the active ingredients in the rodenticide are scavenged by a cultural and historic island food, coconut crab, which then succumb to the poison.

Because of setbacks and damage from Typhoon Chaba and difficulties in shipping and purchasing arrangements, the project was redesigned to allow for the use of different materials and equipment more readily available. A new block of pineapples was replanted and the electric fence installed to test the project’s proposed methods.

OBJECTIVES
Establish a sustainable method for using electric fence to control damage caused by rats to pineapples.

Establish windbreaks by planting da’ok (Callophyllum inophyllum) and Gliricidia sepium trees.

SPECIFIC RESULTS
The principal rodent pest on Rota was identified as Rattus rattus, commonly called roof rat or shipping rat. Damage to pineapple caused by the species is considered a total loss as the damaged fruits can be used for neither fresh nor processed sales.

The effect of the electric fence on rat damage was remarkable: all damage ceased after the fence was installed on April 27, 2004.

BENEFITS OR IMPACTS ON AGRICULTURE AND PRODUCER ADOPTION
Although rats remain a major agricultural pest on Rota, farmers are now better equipped to address the problem through extension efforts (workshops and field days) developed and executed through this project. Agricultural suppliers are now retailing the appropriate materials as a result of lessons learned from this project.

REACTIONS FROM PRODUCERS
The farming community has expressed its appreciation for the efforts and results produced through this project, and commendations have been extended during advisory council meetings, Western SARE writing workshops and a newspaper article.

RECOMMENDATIONS OR NEW HYPOTHESIS
Given the present levels of infestations observed on Rota, farmers would be well advised to adopt the practices used in this project. The local Department of Lands and Natural Resources supports the efforts and recommendations resulting from the project and has solicited financial assistance from USDA.

DISSEMINATION OF FINDINGS
Further extension materials are being developed in collaboration with the CNMI Division of Fish and Wildlife.