By Sharon Atieno
The spread of the Golden Apple Snails, a rice pest native to South America, has brought distress to farmers in Mwea Irrigation Scheme as they struggle to find a lasting solution to the menace.
Reported initially in February 2020, the pest had infested 781 of the vast 26,000 acres under rice irrigation. More than a year later, and the pest has spread to the entire scheme.
Paul Maina, a rice farmer in the scheme, observes that the pests mostly affect the rice at the nursery level during sowing and also within 40 days after transplanting.
At this stage, the crop is tender and succulent, making it easy for the snail to feed on.
“When it is in the nursery, there is no way you can try to manage it, if you don’t remove the water,” he said, adding that the stagnant water creates a conducive environment for the snails to thrive.
To solve this, the farmers have resolved to use a net or wire mesh at the entrance of the water into the field to filter the snails. The strategy works for mature snails but the eggs still manage to pass and attach themselves to the crop, Maina stated.
Alternative wetting and drying of the rice fields, is a strategy that farmers have also utilized to deal with the pests.
Maina says that draining the water completely causes the eggs to dry up thus hatching does not take place.
He adds that during transplanting, some of the pests can be carried with the plant into the main field without the farmer’s awareness. Proper management is needed, so that the crop is not destroyed at this stage, Maina says.
Sicily Wanja, a rice farmer at the scheme, has suffered tremendous loss as a result of this pest. Her nursery was attacked by the crop immediately she planted it. Wanja lost most of her initial crops despite trying to salvage the remaining ones with pesticides from a nearby agrovet.
According to Wanja, she has incurred huge losses, spending money on the pesticides and in purchasing a new set of rice seeds. She had to visit a neighbouring town to purchase seedlings due to shortage in her area. “Things are bad. We need a solution for this thing,” she said.
According to Patrick Tumbo, a rice farmer, other than the mentioned strategies, sometimes they take grass and put it at the entrance of the water such that when they allow the water to come into the field, the grass holds back the snails.
“We come back to handpick the snails from the grass and then put them somewhere in the open far from the farm, where they are sundried to death,” he narrates.
“Another way to deal with them is by digging shallow furrows on the sides of the field such that when the water is drained, the snails are trapped in the furrows and can be easily handpicked.”
Also, farmers are putting kitchen waste such as banana leaves, paw paw leaves, tomatoes and others at the edge of the farms. These attract the snails making it easy for farmers to deal with them.
The hibernating nature of the snails makes controlling the pest very difficult, notes Wilson Mukudi, agronomist, Tana Group Limited.
“When you drain the water, it hibernates under the mud but as soon as you add the water, the snails emerge in the field and feed on the rice especially when it is very young before it starts tillering,” he explained. “It also eats the young tillers thus compromising the yields.”
According to Daudi Aleri, research officer, Mwea Irrigation Agricultural Development (MIAD), the pest has increased the cost of production for farmers.
“ Within the transplanting period, farmers can go to a length of transplanting more than four times just to have the plant established,” he said adding that initially within the 781 acres, MIAD had estimated that the cost of production had gone up by about Kshs. 10 billion (about USD 900 million).
“If the management of the pest is not done fast enough, the impact that would be seen in this area will not be good,” he said.
He adds that the alternate wetting and drying technique requires proper management or else the farmer will incur yield losses.
The visit to the areas affected by the pest was part of a scoping and farmer awareness raising mission by the Ministry of Agriculture Livestock Fisheries and Co–operatives, Plant Protection Services Division (PPSD), Pests Control Product Board (PCPB), Kenya Plant Health Inspectorate Service (KEPHIS), National Irrigation Authority-Mwea Irrigation Agricultural Development (NIA-MIAD), Centre for Agriculture and Biosciences International (CABI), The International Centre of Insect Physiology and Ecology (icipe) and the County Government of Kirinyaga.
