The Agriculture ministry is banking on the rains pounding parts of the country to reduce the spread of the deadly army worm.
The destructive pest eats and destroys all crops in its path.
Kenya Agricultural and Livestock Research Organisation director general Dr Eliud Kireger yesterday said the rains could help reduce the infestation reported in 12 counties.
The army worm was first reported in Trans Nzoia county in March and it has since spread to Baringo, Bungoma, Busia, Kakamega, Kericho, Kwale, Nakuru, Nandi, Taita Taveta and Uasin Gishu.
He told the Star that cold or rainy weather conditions are not favourable for the growth of the worms.
According to the seven-day weather forecast by the Meteorological Department, rainfall is expected over several parts of the country.
Counties that will receive morning rains, afternoon showers and thunderstorms are Baringo, Bomet, Bungoma, Busia, Elgeyo Marakwet, Homa Bay, Kajiado, Kakamega, Kericho, Kisii, Kisumu, Laikipia, Migori, Nakuru, Nandi, Narok, Nyamira, Siaya, Trans Nzoia, Uasin Gishu and Vihiga.
Kitui, Machakos, Makueni and Taita Taveta counties will also experience morning rains on few places while afternoon showers may be more widespread.
Kilifi, Kwale, Lamu, Mombasa and Tana River counties are expected to experience morning showers and sunny intervals in the afternoon.
Last week, the ministry recommended the use of Diazinon, Alpha Cypermethrin, Chlorpyrfos, Diflubenzuron Triclorfon (Dipterex), Chlorantraniliprole, Spinetoram, Emamectin benzoate, Indoxacarba and Lambda Cyhalothrin insecticides.
While touring Trans Nzoia, Agriculture CS Willy Bett said the government has set aside Sh200 million to buy chemicals to be sprayed on farms countrywide.
These products, according to a pamphlet published by the ministry, should be used appropriately at the right environmental conditions to minimise development of pest resistance. They should be sprayed at least three times two weeks after emergence at knee-high level and just before tasseling.
The fall army worm is native to South and North America and in Africa it has been reported in the Democratic Republic of Congo, Malawi, Mozambique, Namibia, South Africa, Zambia and Zimbabwe.
Experts from the Centre for Agriculture and Bio-sciences International say it could take several years before an effective control method against the pest is developed.
Between April 27-28, experts, national plant protection organisations, seed and pest companies from Africa will meet in Nairobi to discuss the status and strategy for effective management.