Controlling African armyworms can be done through use of pesticides and various intercropping methods.
How to apply Pesticides
One litre of the certified permethrin pesticide can be used on three to four acres of land.
For cereals that are around six inches tall, mix 15ml (three bottle caps) in 20 litres of water. A pesticide more concentrated than this may leave the crop scarred.
For older cereals that are about two months old, mix 20ml (use the provided measuring cap) of pesticide in 20 litres of water.
It is advisable to spray the crops early in the morning or in the evening because that is when the worm is most active.
Direct the nozzle of the pump in the middle parts of the crop because that is where the worm hides.
Use protective gear on the hands, feet and eyes while spraying.
Other control methods
Intercropping grains and legumes, intercropping cereals such as maize with legumes keeps the worm at bay.
Use of pheromone traps to monitor the arrival of moths. The traps are similar to those used to trap fruit flies. They trap most of the male moth, hence affecting the mating process. The traps are now commonly sold in agri-inputs stores at as low as sh10,000 each.
An acre of crops may require about three traps.
Early detection is also very key. Look out for larvae and signs of damage early. The worms usually feed on the undersides of leaves, especially new ones. At this stage, you can avoid bigger damage to the crops by hand-picking the caterpillars from the crops.
However, do not kill them on the farm but rather have a bucket with a disinfectant or liquid soap and drop them in. Killing them at the farm may spread the eggs.
Planting early at the beginning of the season also saves the crops. This is because the worms attack fairly late in the season. For example, if a farmer planted in late February when the rains started, the attacks coming in late March may not affect him or her.
Control using birds, soil
Some farmers control the worms by dropping sand or grainy soil in the whorls of the maize plants to prevent the caterpillars from feeding on them.
However, such an exercise is tedious.
Birds eat the moths and will pull larvae from the plants and soils. Before you plant, allow chicken or other domestic birds to scavenge through the drying grasses of the garden.