Multiple yellow stickers that hang in a tomato farm near Kagumo town, Kirinyaga County conspicuously attract the attention of farmers.
The radiant stickers serve as pest control method since yellow is attractive to insects such as aphids and white flies commonly known to attack tomatoes.
The stickers are smeared with an adhesive which trap and kill the insects. The stickers are changed every six months since they also trap dust.
Elijah Gitari Njaria, the farm owner says hanging the yellow stickers is one of the bio pest control methods adopted by his farm.
His farm serves as a demonstration for farmers in the county, on the use of environmentally responsible bio pesticides.
“No synthetic pesticide are used in the one acre portion of land under the tomato cultivation,” says the farmer.
He says many synthetic pesticides contain hazardous chemicals that are a threat to human health and the environment.
Globally, pesticides are being blamed for plummeting bee populations which are crucial in food production as they pollinate close to three quarters of all crop.
Fredrick Mugo Mutuota, a bee expert in Kirinyaga says the declining bee population led to the total ban of the widely used insecticide deneonicotinoids, by the European Union in 2018
In contrast, he says, the bio pesticides made of naturally derived substances, microorganism and plant based protectants targets specific pest and insects and do not pollute the surroundings
To sustainably control moths that plague tomatoes, Njaria farm uses sex pheromones which frustrate the insects mating efforts. Female moths produce pheromones to attract males.
“We apply pheromones on an adhesive paper placed with a brightly colored trap, the colour and the pheromones attract the male moths to the trap where they stick and die,” said Njaria. He said when the males are wiped out, females cannot reproduce and the population dies off.
A light water trap (a light bulb suspended on a rod above a basin of water) has also proven effective in getting rid of insects which are drawn to light.
When the light bulb is lit at night, the light and the warmth produced attracts a range of insects which then drowning in the water.
The trap controls pests such as aphids and white flies. When combined with extracts from various plants, it acts as insects repellants too. This is because certain plants produce chemicals that act as natural deterrents to pests.
“The white flies are harmful to the tomato plants as they suck the sap from the plant, drying it up in the process,” Njaria said
A mixture of tobacco, aloe Vera extracts, ground chili peppers and rosemary leaves effectively wards off insects.
The Kirinyaga County CEC for Agriculture, Jackline Njogu says they are encouraging the farmers to adopt the integrated pest management like that adopted by Njaria farm.
She says the use of natural pest control encourages growth of health crops with minimal possible disruption to agro ecosystem.
“To control bigger pests like the butterflies, Njogu says farmers are advised to use a shade net which covers the crops around the farm.
“The net acts as physical barrier to prevent multiple insects and birds that roam the surroundings from accessing the farm,” she said
An extension officer with the county government, Mary Thimbu says they have also been educating the farmers on the use of another natural pest control method where they suffocate the insects through spreading manure and water on cultivated land and covering it with a polythene bag.
Besides preventing eggs from hatching, this technique promotes buildup of beneficial micro-organism in the soils.
Dr. Jess Kambaka, the Deputy Institute Director KARLO Thika and a Plant Pathologist said they were now out to train the farmers on the integrated pest management.
She said it is possible to use technology which will help reduce pesticide and chemical use.
By Irungu Mwangi