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| A new venture for kandi Farmers | | Lac cultivation in Jammu | | Dr R.K.Gupta and Dr. Kamlesh Bali | 1/15/2020 9:02:34 PM |
| Every one of us is aware about the lakshagriha, the House of Lacquer or House of Wax in Mahabharata meant to be a death trap for the Pandavas. Actually the house was built with the Lac, the natural resinous compound of animal origin. It is secreted by number of species of lac insects, of which the most commonly cultivated is Kerria lacca. Not long ago, collection (geathering) of lac was carried out practically throughout the country including Jammu & Kashmir which contributed significantly to national lac production, but now its share is almost negligible. However, natural occurrences of lac insect, locally called as korh in J&K is well established particularly on ber plants. It is pertinent to mention that lac was found abundantly before 1947 and people used to collect and sell it commercially. Interestingly, this State is bestowed with ample of lac host plants, therefore its cultivation can be revived for the benefit of farming community of the region by scientific cultivation through systematic intervention. Some of the major uses of lac include lacquering, enamelling, sealing, polishes, insulations, medicines, gaskets, abrasives, adhesives etc. Lac dye isolated from the effluent water obtained during lac processing is used for colouring of cloth, animal fibres, soft-drinks, jam etc. Lac has diverse uses. In Ayurveda, Siddha and Unani system of medicine Lac is used for treatment of variety of diseases. In Ayurveda, Lac is considered astringent (Ras/taste), cool (Veerya/potency), and Pungent (Vipaka/post-digetsive effect). It balances pitta-kapha dosh and promotes strength. In Unani, Lac is considered tonic for liver, stomach and intestine. In the pre-industrial era gatherers would collect them whenever they required natural adhesive, they did not culture it artificially. Modern industrial demand introduced artificial inoculation of the insects on their host plants and its management through scientific interventions. The practice of cultivation begins when a farmer gets a stick (broodlac) that contains eggs ready to hatch and ties it to the tree to be infested thousands of lac insects colonize the branches of the host trees and secrete the resinous pigment. The coated branches of the host trees are cut and harvested as sticklac. The harvested sticklac is crushed and sieved to remove impurities. The sieved material is then repeatedly washed to remove insect parts and other soluble material. The resulting product is known as seedlac. The prefix seed refers to its pellet shape. Seedlac which still contains 3-5% impurities is processed into shellac by heat treatment or solvent extraction. has immense economic importance. No doubt the development of many synthetic products have made its importance to a little lesser degree, but still it can be included in the list of necessary articles.
To have a reasonably grounded understanding of lac cultivation once must delve deep into the basic biology associated with the lac insect. The adult lac insect exhibits prominent sexual dimorphism that is, the male and female insect varies in shape, size and also in the presence or absence of certain body parts. The female larvae after settling down once never move again and thus eyes, wings, and legs become useless and ultimately undergo atrophy. It is female lac insect which secretes the resin. After attaining maturity, males emerge out from their cells and walk over the lac encrustations. The male enters the female cell through anal tubular opening and inside female cell it fertilizes the female. After copulation, the male dies. One male is capable of fertilizing several females. Females develop very rapidly after fertilization. They take more sap from plants and exude more resin and wax. The resinous substance, lac is secreted by certain glands present in the abdomen of the female lac insects. The secretion of lac begins immediately after the larval settlement on the new and tender shoots. This secretion appears first as a shining layer which soon gets hardened after coming in contact with air. This makes a coating around the insect and the twig on which it is residing. As the secretion continues the coating around one insect meet and fuses completely with the coating of another insect. In this way a continuous or semi-continuous encrustation of lac is formed on the tender shoots. This encrustation before emergence of larvae is called ari lac and it is scraped off the branches into stick lac before swarming of larvae. The females after fertilization are capable of producing eggs. A female is capable of producing about 200-500 eggs on average. Inside incubating chambers, the eggs hatch into larvae which can crawl for 48 hours. During this period these crawlers begin to wander in search of suitable centre to fix them. This mass movement of larvae from female cell to the new off-shoots of host plant, is termed as "swarming". While swarming happens in the lac encrusted branches they are cut into 15 -20 cm sections and are tied on fresh tender branches of other host trees. These swarming sections are called 'brood lac' or 'Phunki' as they can be used for inoculating lac insects on host trees for fresh crop of lac.The stage wise process of lac rearing involve Initial Pruning of ost plants such as, ber and palash which are pruned before monsoon so that fresh flush of shoots and leaves can emerge during monsoon. The branches less than an inch in diameter are selected for pruning. Branches half inch or less in diameter should be cut from the very base of their origin. But the branches more than half inch diameter should be cut at a distance of 1 ½ inch from the base. The branches remain tender and are ready for inoculation around the third week November. Meanwhile one has to select the brood lac sticks (as seed) for inoculation These sticks are selected from lac bearing trees prior to about two weeks of hatching of larvae, lac bearing sticks are cut to the size of six inches. They are called 'Brood lac'. Brood lacs are then kept for about two weeks in some cool place. When the crawler start emerging from this brood lac, they are supposed to be ready for inoculation. Strings (sutli) are used for tying the brood lac sticks with the tender shoots of the host plant. There are various ways of tying the brood lac. After 21 days brood sticks need to be removed which is called phunki removal. From these phunkis scraping of Lac encrustations can also be done Since, here, the lac is collected before swarming it is called 'ARILAC'. In case of Palas lac (Rangeeni lac), this type of lac was found to give better quality of production. So, only for this lac immature harvesting is encouraged.. However, if cultivated on n Ber we must harvest 'Mature Lac'. It is very important to know the exact date of emergence and swarming of nymphs for mature lac harvesting. A simple visual method is adopted for this purpose. However, a yellow spot develops on the posterior side of the female lac cell toward crop maturity. Then, the spots spread forward until it covers half of the cell. Cutting of twigs for harvesting can be done at any time between the stages. But, the yellow spot occupies one-third to one-half of the cell area. Though, at times it is desirable to wait till the emergence of first new nymphs.
It should be noted that with different inoculation time, harvesting time for different crops also varies. On one hand, the Summer crop is harvested in October/November, Rainy is in May/June. This way the crop mature in 4 month (rainy crop) or 8 month (summer crop). The branches bearing lac are harvested and cut into small sticks which are dried in sun for few days until the scraping of lac from twig which is done with a knife, after which they should not be exposed to the sun. The scraped lac is grinded in hard stone mills. The unnecessary materials are sorted out by hands and also through fine sieve in order to remove finer particles of dirt, following which the lac is repeatedly washed with cold water and is dried under sunlight. At this stage of purification it is called 'Seed lac'. Now a days there are many processing units generally owned by wealthy settlers who own large estates with open courtyards where seed lac is dried under sunlight and may be converted to Shellac which is processed Seed lac s subjected to melting. The melted lac is sieved through cloth and is given the final shape by molding. The final form of lac is called "Shellac". And has over 90 percent resin content. Shellac and seed lac has a long shelf life and are stored in sacks in cooled rooms Stick lac is converted to commercial grades of seed lac and then shellac. The yield of processed lac from stick lac varies between 40-60% depending on the host tree, area of cultivation and other factors. Apart from lac resin, stick lac contains 6-7% of lac wax, 3-5% of water moisture, coloring matter (lac dye), and impurities like insect remains, wood pieces, sand, etc. The refinement of stick lac into seed lac is mostly carried out in cottage or semi mechanized factories. After refinement, seed lac is converted to shellac by hand-made or machine-made process.
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