Rodent control (non-chemical) in lowland irrigated rice
Which rodents are pests in rice?
Many rodents cause problems in rice. The main pests are the "Rice field rat" (Rattus argentiventer), the Black rat (Rattus rattus) and the lesser Bandicoot rat (Bandicota bengalensis). Various mice can also cause problems. The presence of rats is usually associated with tracks in mud and rat holes in bunds and levees.
Why control rodents?
Rodents causes significant losses both in the field and in post-harvest rice management.
Keys to effective rodent control - Community action and Understanding rodent biology
Typical field symptoms include seed eaten at planting, plant sheaths or tillers cut at 45 degrees near the base, or missing grains or panicles. Droppings and half eaten grain are typical symptoms of rodents in grain stores. Different rat species differ in their breeding patterns and places where they live and thrive. Therefore different control strategies are required for different rodents.
Rice field rats: The breeding of the rice field rat is linked to the development of the rice crop and they give birth to 10-14 young. They begin breeding before panicle initiation and stop when the crop ripens. If crops are planted more than two weeks apart then the rats will move to the late-planted crops and continue breeding. The rats live along channel banks and in village gardens during land preparation. These are target habitats for short, intensive, community control campaigns. The rice field rats are very sensitive to human disturbance and so are rarely found in houses and grain stores.
Black rats: Black rats only give birth to 6-10 young but some females breed for most of the year. They therefore require low level but continual community control actions. The black rat thrives around houses and is a major postharvest pest.
Control for both species requires:
Building and maintaining a Trap Barrier System (TBS)
A TBS will have an effect over an area of 200m radius from the TBS (10 ha). A TBS is simple to erect, but to work properly, needs to meet these specifications:
What you need are:
How to build a TBS:
Developed with input from Grant Singleton and MA Bell.