Corn Production Guide: Rodent Management

Rodents and Their Damages

Rodents are nocturnal animals, which can cause heavy damage to corn crops. Evident signs of their presence are gnawing, nibbling, cut plant parts and presence of runways and burrows in cornfields. They readily multiply in areas where there is abundant food.

Rodents concentrate in adjoining grass and other covers following cultivation. Rapid movement into the cornfield is enhanced with more plant and weed covers. Shallow breeding burrows may abound in hilled-up grounds.

Rodent populations increase very rapidly because they, very often, have many offsprings. They can live for one year or longer. Females may reproduce up to four times a year and have an average of six offsprings in a litter.

Rodent Damages in Cornfields

Signs of rodent damages in cornfields are the following:

• Newly planted seeds are excavated and cotyledons are eaten out resulting to kidney-shaped shells.

• Greening to maturing corn ears are dehusked and kernels are partially to fully eaten out, resulting in bare cobs.

Methods of Controlling Rodent Population

Effective rodent management requires a community-based effort. A number of methods can be undertaken to control rodent population in cornfields.

Physical methods:

Blanket system.

This is probably the most popular removal process. It involves driving rodents into a central grass trap where they are eventually killed.

Burrow excavation.

This is preferred over the use of fumigants, flames or water to dislodge occupants.

Others.

Traps, deep trenches and barriers may also be used.

Biological methods:

Predation.

Grass owls, black-winged kites and leopard cats are considered as primary predators. Most other wild cats are secondary rat feeders along with monitor lizards and snakes.

Habitat manipulation.

The habitat of rodents is modified to make it unsuitable for occupancy.