Secrets of farming silkworms for higher profits

Silkworm farming could soon be the next money-spinner for Ugandans, following the launch of the Iran Agro Sericulture farm in Kisozi, Gomba District.
In Gomba, where the farm is located, lies an ambitious plan to rejuvenate and elevate Uganda into a world class silk producer by Iranian investor Seyed Mohammad Ali Mousavi.
Global demand for silk is growing exponentially and Seyed emphasises on increasing area of sericulture – the rearing of silkworms for silk in Uganda to tap into the global demand.

Product on demand
The world’s largest silk producers, China and India, are encountering a challenge that Uganda can capitalise on.
Both have registered a decline in production, failing to meet the market demand.

The gap, of course, opens the race and for Uganda, the arable climate and good soils for growing mulberry, the only plant that silk worms feed on, is an opportunity.
With more than three million mulberry plants on 1,000 hectares, Seyed wants to cultivate up to 4,000 hectares for a product, he says, can earn more than Uganda’s leading export, coffee.
“At a conservative market price of $50 per kilogramme, that is a huge return on investment,” Clet Wandui Masiga, the lead sericulture researcher, said.

He adds: “Should the government efforts bear fruits, the nation will earn at least $93 million in revenue on a yearly basis. In addition to the multi-million harvest, the industry will open over 50,000 jobs to the youth.”
In 1992, sericulture collapsed due to inadequate market and lack of commercial volumes but at Kisozi, centralised gardens will be promoted with a minimum of 100 acres for farmers’ groups given priority.

How the white gold is made
The silkworm goes through five stages before it reaches maturity to produce the cocoons of silk.
The female silkworms deposit 300 to 400 eggs, about the size of a pinhead, at a time. The female dies almost immediately after laying the eggs and the male lives only a short while longer.
The larvae hatch in about 10 days and once hatched, they are put under a raised tray and fed huge amounts of mulberry leaves, during which time they shed their skin four times.
Over the next four days, one by one, they are placed in a hatching tray and each caterpillar begins spinning a cocoon in a state of sleep.
It normally takes 16 days in the cocoon for the worm to emerge as a winged moth.

However, if the pupa inside the cocoon stays alive it begins to eat its way through ruining the silk thread.
For this reason, during the commercial production of silk, most of the silkworms are killed by immersing them in boiled water.
The harvested cocoons are then soaked in boiling water to soften the silk fibres before they are unwound to produce a continuous thread. A single thread is usually up to 1,200m long. The fibres are spun together to form the yarn that is wound onto reels.
Finally, the yarn is dried, and the raw silk is packed according to quality. The climax is fabric making.

 

What to do
Sericulture is labour-intensive. In an acre of mulberry, not less than five workers should be employed because the plants need constant weeding and fertilisation using silkworm waste and other manure. A prospective farmer needs to establish a mulberry garden. According to Fredric Luyimbaazi, an entomologist, the cuttings, should be with about three buds.

They are best planted at the onset of the rains. Cuttings are planted 3X3 feet apart with five feet separating rows.
During the early stages, the garden is weeded manually. Plants are ready for harvesting at six months but full production starts between two and three years.

For individual farmers, Christine Asaba, the principal entomologist at the Ministry of Agriculture, Animal Industries and Fisheries says, individual farmers need to start with one to two acres.
About 3,300 trees can be planted in an acre and these can feed about 800,000 worms. Rearing can be done between five and eight times a year. Silkworms are reared in specially built houses that must be rodent-free and have enough light and air.

The egg period may last for 11-14 days, the larval period 24-30 days, the pupal period 12-15 days and the adult stage 6-10 days.
This means that a farmer who gets hatched silkworms can rear, harvest and sell cocoons in about five weeks, representing a much faster business cycle than most other agro-businesses.
It is estimated that an acre can generate Shs13m in selling cocoons only. This amount double to Shs26m after yarning, yet up to Shs60m can be earned from making fabric.

Challenges
The worms demand a lot of feeding. They need constant feeding usually, three times a day. Other challenges include pests especially grasshoppers and crickets on the mulberry plants and diseases such as leaf spot and other fungal infections. Since the worms are harmless, they can be attacked by the smallest of insects.

Mulberry seeds
The National Sericulture Centre in Kawanda offers farmers mulberry seeds and silkworm eggs to supplement efforts of investors such as Seyed.

Benefits of growing silkworms
The silkworm is the larva of a moth that is economically important as the producer of silk. Its diet consists solely of mulberry leaves and it is native to northern China.
The silkworm is so called because it spins its cocoon from raw silk. The co

coon is made of a single continuous thread of raw silk from 1,000 to 3,000 feet.
Silkworms eat mulberry leaves day and night continuously. Thus, they grow very fast. When the colour of their heads turn darker it means that it is time for them to moult.
After they moult about four times, their bodies turn slightly yellow and their skin becomes tighter, which means they are going to cover themselves with a silky cocoon.
If the caterpillar is left to eat its

way out of the cocoon naturally, the threads will be cut short and the silk will be useless, so silkworm cocoons are thrown into boiling water, which kills the silkworms and also makes the cocoons easier to unravel.
The silkworm itself is often eaten. The adult moth has been bred for silk production and cannot fly. It is also called the silkworm-moth or mulberry silkworm.
Because of its long history and economic importance, the silkworm genome has been the object of considerable modern study.

History
In China, there is a legend that the discovery of the silkworm’s silk was by an ancient empress called Xi Ling-Shi. She was walking around when she noticed the worms. She used her finger to touch it, and a strand of silk came out. As more came out and wrapped around her finger, she slowly felt a warm sensation. When the silk ran out, she saw a small cocoon. In an instant, she realised that this cocoon was the source of the silk. She taught this to the people.

Medicinal use
Silkworm is the source of the traditional Chinese medicine “bombyx batryticatus” or “stiff silkworm”. It is the dried body of the 5th stage larva which has died of the white muscadine disease caused by the infection of the fungus Beauveria bassiana. Its uses are to dispel wind, dissolve phlegm and relieve spasms.