Authors: Ashish Kumar* and Jnanesha A C
Introduction:
Madhunashini (Gymnema sylvestre R. Br.) Commonly known as ‘Gurmar’ in a Hindi is an important medicinal climber belonging to the family Asclepiadaceae. In India, it is found growing in the forests of Andhara Pradesh, Bihar, Chhatisgarh, Karnataka, Kerala, Madhya Pradesh, Maharastra, Orissa, Tamil Nadu, Uttar Pradesh and West Bengal. The plant is popularly known as 'Gurmar' for its distinctive property of temporarily destroying the taste of sweetness.
G. sylvestre is the second bestselling medicinal plant in the world market requiring a cost-effective and simple method of cultivation to meet its growing demand. Present demand is mostly met from wild collection. Therefore, the only way to meet the increasing demand and reduce the pressure of harvest from wild is its large scale cultivation. Gymnema is a gregarious woody climber, much branched, running over the tops of tall trees. Young stems and branches are pubescent. Leaves are 3–5 cm long and up to 3 cm broad, ovate-elliptic, acute or shortly acuminate, pubescent on both sides; base rounded or heart shaped with 6–13 mm long pubescent petioles. Flowering occurs in October–January, while fruits mature from March to May.
Cultivation practices:
Soil and Climate:
The crop is found growing on a variety of soil in different localities. Red sandy loam or medium deep black soils are reported to be ideal for this crop. The plant is sensitive to water logging and hence its cultivation on such soil should be avoided. Gurmar prefers tropical and subtropical type of climate.
Land preparation:
Before transplanting properly prepares the land for good cultivation. After 2-3 ploughing and leveling the land, 50cm3 sized pits are made at a distance of 2.5 m between the rows and 1.8 m between plants (with in the row. The pits are dug 15 days prior to planting, and are filled with green leaves and top soil, and 10 kg of well-rotted manure is added to each pit. The pits are to be irrigated and left for one week, and then the rooted cuttings are planted and provided with irrigation if there are no rains.
Types: Based on the leaf size: The gurmar woody climber can be classified into two types.
1. Small leaves type: Leaves are oval measuring 1.03.5 cm length and 1.5-2.5 cm very soft, found in dry regions.
2. Broad and pubescent type: These leaves are also oval measuring 36 cm in length and 3.5-5.0 cm in width. Leaves and dark green compared to small leaves type and are pubescent.
Propagation material:
Seed germination is poor; hence, plants are preferably raised vegetative through cuttings. Terminal and axillary cuttings with three to four nodes from one-year-old plants are the best planting material. Cuttings can be obtained throughout the year in moist humid conditions of South India. In North and Central India, cuttings are preferably planted in February–March.
Raising propagules:
Polybags are filled with soil, sand, and FYM (farmyard manure) in 1:2:1 ratio and terminal or axillary cuttings are planted in them. Vermi compost may be used in place of FYM. February to March is the best season for planting the cuttings in nursery, especially in North Indian conditions. The cuttings are placed under humid conditions in shade houses or mist chambers for development of roots. Rooting is initiated within a month of planting. Seed setting is poor in this species and the seeds show a maximum germination percentage of 50%–55% when sown in soil mixed with vermicompost.
Transplanting time and Spacing:
The period between June and August is best for transplanting the rooted plants in the field. An optimum spacing of 1 m × 1.5 m is recommended for a crop stand of about 6700 plants per hectare. The rooted cuttings/seedlings may be planted by crow bar method.
Manures and Fertilizers:
About 10–12 tones/hectare of FYM is applied as basal dose at the time of land preparation. An additional equal dose may be added every year for maximizing biomass production. The gurmar have to be grown without chemical fertilizers. Use of Organic manures like, Farm Yard Manure (FYM), Vermi-Compost and Green Manure etc.
Irrigation:
Irrigation is given immediately after planting and after is required at least once in a week during summer season. Frequency may also depend on the soil moisture in winter. It may be limited to one per month.
Hoeing:
Weeds compete with the plants for water and nutrients; an area of one meter around the plant needs to be kept clean by hand weeding at periodical intervals.
Disease and pest control:
An aphid (Aphid sp.) is observed to attack the apical tender parts of the plant during rainy season. However, if the damage is not severe, no control measures are required. Use of chemical pesticides should be avoided since leaves are to be regularly plucked for harvest.
Value addition:
The plant and its extracts possess immense medicinal and pharmaceutical value in both domestic and international markets. In domestic and international market Gymnema extracts are available in different forms or as ingredients in various Ayurvedic and medicinal formulations. It is because of its immense medicinal value; in spite of wide spread distribution Gymnema sylvestre in India, the plant is considered as endangered because of its over exploitation in the nature for commercial use by pharmaceutical companies and traditional medicine practitioners.
Table1. Value added products from Gurmar leaves
| Sl. No. | Products |
| 1. | Gymnema leaf powder |
| 2. | Gymnema capsules |
| 3. | Gymnema herbal tea |
| 4. | Tablets and other drugs |
Harvesting and yield:
The crop was ready for harvest after two years of planting. Leaves are the economic part and the harvesting of the leaves was done twice in the year. First harvest was done when the plant started flowering, i.e. during June and second harvest was done in September-October. Direct sunlight was avoided to maintain quality of the leaves. Leaves were harvested by hand plucking and the main stem was not cut during harvest of leaves unlike the prevailing practice. Leaves are dried in shade and the dried leaves are packed in polythene bags. The moisture content of the dry leaves should be less than 8% to prevent deterioration. Total yield of dry leaves was found to be 1.5 tones/ha. The crop can be cultivated for 10-15 years under good management.
Conclusion
Gymenma was a traditional medicinal plant and it leaves have wonderful medicinal properties and it was very effective for the treatment of diabetics. It is because of its immense medicinal value; in spite of wide spread distribution
Gymnema sylvestre in India, the plant is considered as endangered because of its overexploitation in the nature for commercial use by pharmaceutical companies and traditional medicine practitioners. Due to a lack of successful agro techniques, however, the plant has become vulnerable and therefore, the different varieties and populations growing in various phytogeographical regions merit attention of the research community.
References:
1. Agro-techniques of selected medicinal plants vol-1, National medicinal plants board, New Delhi, page-89.
2. Garrow JS., James W.P., Human Nutrition and Dietetics. 9th edition, Churchill Livingston 1993; 521.
3. K. R. Kirtikar and B. D. Basu, Indian Medicinal Plants, vol. 3, Periodicals Experts, Delhi, India, 1975.
About Author / Additional Info:
I am working as Scientific Assistant (Agro technology of medicinal and aromatic plants)