India has a unique environmental heritage, representing almost all types of habitats of the world. India is one of the world''s 12 leading biodiversity centres and it is unmatched due to presence of 16 different agro-climatic zones, 10 vegetative ones, 25 biotic provinces and 426 biomass (habitats of specific species). Also being an epitome of climates, seasons and soils of the world, India is a variable garden of more than 2,000 species of known medicinal plants. This medicinal plant wealth is a treasure for Indian System of Medicine. At present, about 1,500 drug yielding plants are well identified and are well-known for their use as medicaments by the profession and their applications in about 4,000 drug industries, which is about 12% of the present flora. About 500 medicinal plants are most commonly used by ISM industry.

Present Source of raw material
The present source of the herbal raw material for the pharmaceutical industries is met basically from the forest form the forest in hilly areas and the plains of the country. Similarly, a number of drugs are collected annually from the wild sources in the plains, fields and waste places all over the country, and to a lesser extent from the cultivated sources. A number of plants grown and planted in the roadsides, garden and home yards (i.e from the social forestry) provide the raw material for the industry. There are other plants also which provide a sufficient amount of raw material grow wild in the forest ones, classified by the forest department as minor forest produce for the indigenous drug industry.

Present mode of Procurement
As far as the procurement, collection, cultivation, sale, purchase, import and export of the medicinal herbs are concerned, as such, there is no definite procedure and no scientific data are available in the country. There is no agency or body to look into such vital and important aspect of the herbal medicine of ISM under one banner.

The recently formed Medicinal Plant Board is still in the infant stage. The bigger supply of the raw material is procured from the drug dealers. They procure the drug from sources, which they keep as part of their trade secret and the material is sold at their prices.

The prices of these drugs could be controlled if any organized and uninterrupted supply of genuine raw drugs is made available to the industry through some co-operative society (like the Amul pattern) under the control of ''Medicinal Plant Board.''

- Cultivation aspects and those basic aspects, which are relevant to carry out research on cultivation aspect

- Utilization aspect and identification aspect.

- Marketing aspect.

Information on utilization aspects are known for many medicinal plants but information on cultivation aspect is scanty especially for plants which are useful in Traditional System of Medicine.

Recently biotechnology has restructured our production of pure natural products, even the planting material is being produced by this technology. Otherwise, the propagation of medicinal plants is done through conventional methods. The agro-technology of medicinal plants is required to be developed scientifically.

Cultivation of Medicinal Plants
Many of the medicinal plants used by ISM industry have got good potential for export also. It is not always possible to depend on wild sources. Cultivation will ensure the quality, purity and regular supply of crude drugs and permits the application of modern technological aspects such as mutation, polyploidy and hybridization.

Medicinal plant cultivation is best limited to marginal lands and to socially and economically farming communities. It could relatively be easy to convince these categories of farmers, as they may not be following a set crop pattern for want of funds and adequate water. The list of medicinal plants is exhaustive and it may not be necessary to cultivate all of them. Ayurvedic companies like Zandu, Dabur etc. have invested considerable funds into research on agro technology aspects of medicinal plants. Zandu Foundation For Health Care has developed agro-technologies for many medicinal plants.

Present Problems in Cultivation of Medicinal Plants
- Lack of complete and reliable information on cultivation practices.

- Hardly and information is available on the economics involved in cultivation of medicinal crops.

- There are no established sources to obtain authentic starting/planting material like seed, sapling, cuttings etc.

- No buy-back guarantee given to cultivators except few companies.

Medicinal Plants can be propagated by two usual methods as applicable to non-medicinal plants or corps. These methods are referred as sexual method and asexual method.

In case of sexual method, the plants are raised form seeds are such plants are known as seedlings. In case of asexual method of vegetative propagation, the vegetative part of a plant such as stem or root is placed in such environment that it develops into a new plant.

The cultivation of many important medicinal plants can meet the growing demand of industries, conserve natural population, facilitate availability of standardized raw material and regulate market supply in the long run. Moreover cultivated materials fetches higher price in the market due to its improved quality. In agricultural research, medicinal plants has brought some interesting knowledge on the following selected medicinal plants which could change the herbal products scenario into a multi dimension mega industry in India.

Phyllanthus emblica (Amla)
Amla fruit is highly nutritious and used as diuretic, laxative, tonic, anti-ageing properties and for various other ailments. It is a medium sized tree. There are sine grafted lines come in bearing early at 4th year over seed raised ones (6-7 years) and gives higher fruit yield of 5-12 tons/hr/annum.

Mucuna Pruriens (Kawach)
The seeds of this trailing annual legume are prescribed to promote male virility and Parkinson''s disease. There are some non-itching cultivated lines cultivated in India and they are found to produce more than 700 kg/acre seed yield with high I-dopa in their seeds.

Acorus calamus (Vacha)
This plant is propagated through rhizome. The crop is harvested after 18 months and rhizome is used for medicinal purpose. This perennil plant grows generally all over loam to sandy loam soil, producing 1-1.5 tons of dry rhizome per acre.

Centella asiatica (Manduk parni)
Mandukaparni is the perennial creeping plant which grows throughout tropical and sub-tropical India. It propagates through runners and plant is harvested at an interval of 3-4 months for commercial purpose. It yields 1-1.5 tons dry plant/acre/annum.

Andrographis paniculata (Kalmegh)
This plant is grown during monsoon season over sandy-loam solid and propagated through seeds. The whole plant is harvested after four months, expected to yield around 1 ton dry per acre.

Asparagus racemosus (Shatawari)
It is a 24 months crops, gives about 1.5 to 2 tons dry tuber acre/annum.

Withania somnifera (Ashwagandha)
It is a 9 month crop and gives 250-300 kgs of dry root/acre.

Cassia angustifolia (Senna)
Grown on marginal and red lateritic soil. It is a small perennial, branched undershrub. Plant remains for 6-7 months in the field and gives 400 kgs dry leaves and about 40 kgs of pods/acre.

The pilot scale cultivation of these medicinal plants have already been carried out by some self funded organization and have also been commercialized through contract cultivation.

Some major research centres which are engaged in the field of development and propagation of medicinal plants are:-

CIMPA, Lucknow - Central Institute of Medicinal And Aromatic Plants

CDRI, Lucknow - Central Drug Research Institute

RRL, Jammu - Regional Research Laboratory, Jammu

ZFFHC, Mumbai - Zandu Foundation For Health Care, Mumbai

Gujarat Agricultural University, Anand

Still the work on medicinal crops needs to be carried out with far more imagination and inter institutional collaboration. Research on medicinal plants suffers for lack of mechanism for systematically and routinely introducing and investigating plants which are little known to agricultural but are therapeutically useful medicinal plants.

-- The author is vice-president, Zandu Pharmaceutical Works Ltd.