Mulberry Cultivation: Karnataka

Karnataka, Andhra Pradesh, West Bengal, Tamil Nadu, Jammu & Kashmir and the north-eastern states of India are the major mulberry silk producing centres, with Karnataka taking the lead at 40% of the silk produced today in the country. Organised sericulture was first brought to Mysore in Karnataka by Tipu Sultan in 1785. Mulberry cultivation needs a cool environment, with temperatures in the range of 25-27C with minimal fluctuation in the day and night temperatures. The regions around Mysore, Kolar, Ramnagar and Chikballapur in Karnataka are ideally suited for sericulture, and it provides jobs for 10.67 lakh people in the state.

The mulberry silk cocoons are yellow or white in colour and are made up of long, individual fibres, more uniform, refined and durable than any other silk. The yellow cocoons are the indigenous variety, once found in the wild. This local Mysore variety has a beautiful soft matte lustre. Over the centuries, silkworm farmers selectively bred them for whiter cocoons until they achieved the pure white that we see today, which is preferred as it can be dyed in any shade without having to bleach the yarn. The natural wild silk had a charming uneven wave that has been lost in the hybrid or bivoltine cocoons that are pure white. There is always some gain and some loss when indigenous varieties are altered for a higher output. The yellow native cocoon gives approximately 800 metres of running thread compared to 1200 metres from the cross-bred varieties. Six kilograms of white cocoons yield one kilogram of silk, whereas ten to twelve kilograms of the yellow indigenous variety would give one kilogram of silk. The hybrid varieties are preferred as the yield is better, which means better earnings for the farmer.

The silk moth lays about 300 to 500 tiny eggs and dies soon after. The initial stage from egg to hatching is now done in sterilised, temperature controlled rooms by experts, in government godowns, to control infection and provide healthy seeds to the farmers. This has helped curb many infections and diseases and farmers are now assured of a healthy crop. When ready to hatch, the seeds are given to the farmers. One sheet or cover contains around 400 to 500 eggs, and it is given to the farmer for a few rupees. The input cost is very low, so a farmer, can buy several sheets of mulberry eggs, depending on the availability of castor leaves. When hatched, each egg becomes a cocoon.

The rearing room at the farmer’s place is meticulously cleaned and the trays are sun-dried, disinfected and sterilised before getting a new batch of eggs for rearing. It takes around eight days for the local variety to hatch. Cross-breeds take a little longer, around 12-13 days. From hatching to cocoon takes around 23 days. The silkworms are voracious eaters and need a regular supply of chopped mulberry leaves, which are provided two or three times a day.

Mulberry, the food plant of silkworms, is a perennial crop, and once planted can be maintained for years without much effort. One acre of mulberry plantation is good for 200 covers or sheets per batch, that is, around 60,000 to 80,000 eggs. Thousands of feeding worms are kept in trays stacked one on top of another. A roomful of munching worms sound like heavy rain falling on the roof. The newly hatched silkworms multiply their weight 10,000 times within a month, changing colour and shedding their whitish grey skin several times. The cocoons needs constant monitoring as the worms are very sensitive and prone to infection.

Once the worms are ready to spin their cocoons, they are individually placed on a bamboo tray. Neem leaves are kept in the tray as a disinfectant and also as a good omen (nazar nahi lage). The silkworm caterpillar builds its cocoon by surrounding itself with a long, continuous fibre, or filament. It swings itself from side to side in a figure-of-eight movement distributing its saliva, which solidifies when it comes in contact with air and forms the silk filament. Silkworms spend three or four days spinning a cocoon around themselves until they look like puffy, white balls. Each silkworm spins approximately one mile of filament. It takes around 45 kilograms of mulberry leaves to feed between 2500 and 3000 silkworms, the number required to make half a kilogram of silk. It would take over 5000 silkworms to make a pure silk saree. With a single rearing house of around 7.5 x 15 metres and an acre of mulberry plantation, a farmer can get 4 crops per year, earning around Rs.75,000 per cycle. Without a huge investment and low recurring costs, the farmer can earn a decent, supplementary income through sericulture.