A group of women from western Kenya has ventured into silkworm production to make a steady and more income of about Sh75,000 each per month after replacing sugarcane with mulberry, the staple diet for silkworms.
Before its formation about 14 years ago, Kambogo Women’s Group found in Rachuonyo, Homabay County had most of its members, who had not become part of the group, growing sugarcane which they had to wait for 18 months to begin earning as opposed to monthly income from silkworm.
The group learned about the venture from one of them, Pamela Onyango, who borrowed the idea from a farming group in Uganda before luring colleagues who saw the lucrative returns of the venture.
“I learned about silkworm production from Uganda and tried it out in a grass-thatched house having learnt the skill of egg production from a silk farming group in Buseni,” said Ms. Onyango.
To form the cocoon, she explains, silkworm larvae feed on mulberry leaves before climbing onto a twig placed nearby, where they spin their silken cocoons.
The group is currently comprised of 30 members with over 15 acres of mulberry bushes having acquired basic skills in rearing silkworms from the International Centre for Insect Physiology and Ecology (ICIPE).
It has now commercialised its activities by selling the cocoons on a monthly basis to the Kenya Agricultural and Livestock Research Organisation (KALRO) in Thika besides offering lessons at a fee to farmers who want to practice silk farming.
A kilo of silkworm cocoon goes at Sh2,500 and the groups is able to produce 10-30 kilos a month raking the group about Sh225,000 a month.
“Many people are now willing to practice silk farming because it is less tedious, yet it brings income on a monthly basis as opposed to other cash crops which take long to mature and farmers have to wait for at least a month before receiving their pay,” said Ms. Onyango who is now the group chairperson.
One acre of mulberry can yield up to 4 boxes of silkworms per cycle. With good quality silkworm hybrids and proper rearing skills, each box can produce an average of 20–30 kg wet weight of cocoons depending on weather conditions, which translates to 80– 120 kg of cocoons per cycle.
Assuming there are five rearing cycles a year, a farmer can produce 400–600 kg of cocoons, at US$ 3 per kilo, thus earning approximately US$ 1200–US$ 1800 annually.
Starting off in silkworm farming
According to ICIPE, cultivating mulberry is the first step in sericulture (silkworm farming). Mulberry is grown using the vegetative plant parts, direct to the farm or in nursery beds. A minimum one-acre of mulberry is recommended for initiating for starters.
Before the onset of rains, the land is prepared by weeding, ploughing, digging, and levelling. Seven tonnes of farmyard manure per acre per annum is mixed with the soil. The mulberry cuttings are planted at the onset of the rains. The type of mulberry variety used depends on the climate and soil type.
If the soil is fertile, 5000 mulberry cuttings per acre in 3 x 3 feet rows are planted; but if the soil is less fertile, 11,000 cuttings per acre in 2 x 2 feet rows are planted. Only the mulberry cuttings that have 5 or 6 buds are selected.
On average, in 7 to 8 months, the new mulberry plants will have sufficient foliage to support rearing of one box of 20,000 silkworms. If the rains fail after planting, the land is irrigated once every 15 days. Pruning is recommended after the mulberry is one year old; and plants can, thereafter, support up to 4 boxes of silkworms. Subsequent pruning is done twice a year.
Rearing house and appliances
A rearing house, either of mud or wood should be at least 25 x 20 x 10 feet with adequate ventilation rearing the silk larvae.
This house should have the capacity to hold 2 to 3 boxes of silk larvae. The rearing equipment includes three-tier rearing wooden or bamboo bed racks for tray rearing, mountages, wooden or bamboo trays, knives, cleaning nets, baskets for collecting the leaves, a leaf chamber (4 x 3 x 2 feet), and ant wells to protect the larvae.
A high level of hygiene is required inside the house; and a disinfectant (2% solution of formalin and lime powder), is sprinkled on the doors before initiating rearing. In the first year, if the rains are favourable, one cycle of silk larvae rearing is possible. As one gains experience, 4 to 5 rearing cycles per year are achievable.
Purchase silkworm eggs from high yielding bivoltine Bombyx mori hybrids sourced from a reputable silk larvae egg production grainage, where the eggs are stored at 3°C.
Prior to incubation and supply to farmers, eggs are removed from the cold storage and brought to room temperature.
These eggs should be transported to the rearing farm during the cool hours of the day, to avoid drying out. Eggs are incubated at 20 – 22°C for 5 days and 25 – 26°C for another 4 – 5 days at a relative humidity of 80%, with a cycle of 12 hours light: 12 hours dark so that 98% of the silkworm eggs hatch.
They are placed in a black box or covered with black paper, 24 hours before hatching, to ensure uniform embryonic growth. On the day of hatching, eggs are exposed to light.
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