Written by the Web Team
Philippine Rice Research Institute (PhilRice) advises rice farmers in six municipalities in Isabela and some parts in Bicol and Nueva Ecija to cautiously use rodenticides as poison rat baits. Farmers in these areas have often resorted to rodenticides in reducing rat’s population.
Florencio Viesca Jr., rice and corn coordinator of the provincial agriculture office of Isabela, confirmed that 900 ha of rice fields have been rat-infested since last week of December last year. The infestation hit rice during vegetative stage with damages reaching 16 percent; prompting the provincial agriculture office to recommend baiting.
Among poison rat baits, PhilRice crop protection expert Ulysses Duque recommended zinc phosphide, an inorganic chemical compound with strong pungent odor.
“This black-gray powder could reduce rat`s population. However, it is lethal to humans and non-target animals, so farmers need to be very careful in using this bait. Always wear gloves and mask when preparing the bait,” Duque cautioned.
According to Duque, field sanitation and using barrier systems are already ineffective when damages hit the vegetative stage. He said that rat management starts at least a month before seeding and reproductive stages, as these are the periods when rats reproduced.
To prepare the bait, Duque instructed farmers to mix a sachet of zinc phosphide with 300-400g of good quality rice then place the baits in small plastics such as ice candy wrappers. A kilo of the mixture produces 100 packs of baits enough for a hectare of rice farm.
A member of PhilRice rat management system team, Duque stressed that placing baits in rat burrows is safer and more effective than scattering them in bunds as baits sheltered in burrows are protected from weather exposures.
“Farmers also usually spread the mixture unenclosed in the field. This is impractical because the mixture losses its effectiveness when soaked. This practice is also harmful for livestock and other animals as they could take in the chemical,” Duque said.
Duque also advised farmers to complement baiting with community rat hunting during the day concentrating on rat burrows. Farmers may also use flamethrowers to drive out the pests from their habitat.
However, he reminded farmers not to eat collected rats from baited field as this leads to poisoning.
Rat infestations, Duque added, usually occur after heavy rains and floods.
“During good weather, rat population is dispersed in the field. However, their habitat is disturbed during floods, leading them to seek higher grounds for survival,” Duque said.
With the rat infestation, Duque said farmers could still yield 10-20 percent from rice ratoons or stubbles, although they have to watch out for weeds as their population grows rapidly following rat attacks.