A wonder medicinal plant:Senna

Ayurveda is a precious and wonderful divine gift given by the almighty God Brahma the creator, to the human beings It is precious as it gives us the knowledge of preventing or curing obstacles (i.e Diseases) in one’s physical and mental well being and makes him enable to live and think healthily. It wonderful as it identifies the supreme position of human being or Purusha among all other living organism and formulation of the theory of Pancha Mahabhutas. The five Maha-bhutas (Akasha-Space, Vayu-Air, Agni-Fire, Apya-Water, Bhumi-Earth) are the final manifestation of nature, its living and non-living objects. On one side living body is composed of five Bhutas, on the other, diet and drugs are also composed of five Bhutas, the objective of Ayurveda is : To keep a healthy person healthy and also to provide relief to a patient suffering from disease.Ayurveda is a Sanskrit term where “Ayu” means “life” and “Veda” means “Science or Knowledge” Thus “Ayurveda” is “The Science of Life.”

History of senna
Senna is wonder medicinal plant. It is not a plant of Indian origin. It is native in South Arabia and now under cultivation in India. In the vedic period (4500-1600 B.C), details are not available regarding the utility, classification, list of human diseases against which they were applied and the associations in which they were applied.Thereafter, in classical or Samhita period (from 1600 B.C.) Samhitas of Charaka. Sushruta, Hasita, Bhela and Kashyap etc. were written. They have given tables of classification of medicinal plants. In the classicals, Senna is not mentioned with any synonyms. At that time this plant was not grow in India.

The post Samhita period is known as the Sangraha period when complications were written during different periods in the various parts of the country. From the 15th century onwards the ge of Nighatus appeared, which are more in the nature of Materia Medica with greater emphasis on drug description and synonyms. In the Nighantu, Senna was mentioned with number of synonyms. Senna was included as an official drug by the Nighantus in 15th century, however, after reviewing the history, one can experience that the Senna is not a classical drug.

The plant
Senna is variable branching erect shrub up to one meter in height. Leaves pinnate, pubescent, leaflets pale to green to bluish-green, 3-9 pairs, lanceolate or elliptic; varying on some plant, 1.5-5.0 cm x 0.4-2.0 cm. Flowers brilliant yellow, in erect, terminal racemes; pods light green when young to dark-brown or black when mature, flat, think, oblong, pubescent, 3.5 to 7.0 cm. x 0.2 – 2.5 cm. Seeds dark brown, obovate-oblong and 5 to 7 in number.

Senna is widely used in Ayurveda, Unani, Siddha, Allopathy and other traditional systems of medicine mainly because of the laxative property of its aerial parts. The laxative property is mainly due to chemicals, namely sennoside A, B, C & D. The demand of leaves and pods are very high increasing day by day due to too much use in Ayurvedic preparations, herbal teas, bakery products and other home preparations all over the world.

Production practices by organic farming in desert
Lands and its preparation : Sandy and sandy loam soils are suitable for the cultivation of this crop. The marshy land and the fields, which remain under water stagnation should not be selected for the cultivation of the crop. Since light soils are suitable for this crop, 2-3 ploughing by cultivator is optimum. Planking and removal of weeds and residues of the crop are essential for better germination and proper growth of the crop.

Time of sowing : Senna should be sown just after the first monsoon rain. The sowing time stretches from 15th July to 15th September. The optimum moisture in the soil at the time of sowing of the seed is essential for proper germination and establishment of the seedlings. In the undulated land and sand dunes of Rajasthan/Desert the seeds may be dry sown even in the month of June. The seeds would germinate as soon as it rains.Methods of sowing and seed rate : The sowing can be done at 30 cm x 30 cm spacing with a depth of 2-3 cm. It can be sown by broad casting method or by line sowing. For planting one hectare of land 10 kg seeds would be sufficient.

Eco-friendly cultivation : Hence the plant is perennial, therefore, once sown, does not need to be sown every year. This save the expenditure of tectorisation and fuel use. The plant does not require any weeding and pest management practices, which reduces the use of hazardous agricultural chemicals and save environment. The plant does not require irrigation and land remains dry. These conditions prevent the occurrence of pathogens. The plant is not being grazed by domestic or wild animals, therefore, there is no need of protection.

Weeding, manuring and pest & diseases management
The livestock like sheep and goat moving in the field eat all types of weeds except senna plant, therefore weeding is not required.The plant is deep rooted (upto 8 feet), and also non-irrigated, therefore manuring is required. The plant is resistant to all kinds of fungal diseases and to pests. The high intensity of light and hot temperature prevent the pathogens to infect the plant.
Cutting management : Leaves are the main economic part of the plant. The cutting should be done when the leaves contain higher percentage of sennoside.

This stage appears before flowering. The crop is cut at 5-10 cm above the ground level. The crop blooms fully at least three times in the year, therefore three cuttings can be done yearly. It has been observed that the best time of harvesting is the second fortnight of October, February and May. This crop is susceptible to frost, thus October cutting should not be delayed. It is important to note that cutting should not be done in cloudy atmosphere because the clear sunlight will help in drying of plant material.

Post harvestment management
Drying and separation of leaves : After cutting, the small heaps are made and kept in sunlight for 1-2 days to reduce the moisture content of plant parts. Thereafter, a big heap is made from the small heaps and wait for proper drying.After dying, the leaves are separated from the twig by soft beating. Small pieces of twigs still remain with leaves, which are separated in the winoyer. On the basis of leaf size, the grading of leaves is done in the grading machine. Finally, the material is packed in gunny bags or packed in jute-bags under pressure for long distance transport.

Leaves yield: About 1000 kg/hec dry leaves can be obtained in yearly.
Seed production : Although seed is not an economically useful produce, yet for getting the own seed for large scale cultivation it has been found that the crop which is grown for quality seeds, should be harvested only once and that too in the month of May. The mature dark brown pods are collected in the morning and seed can be threshed out easily by rubbing of the pods.
Seeds yield : Seed yield of 150 kg/hec. can be obtained yearly.

Economics : This crop is highly remunerative for the lands from where farmers are unable to get even Rs.1000/hec/year and that too without high inputs like water, fertilisers, pesticides etc.
Marketing : Senna is having good national as well as international market. Moreover, the demand of Indian senna is increasing in the International market (specially desert Senna – due to its potential) as revealed by export data which shows that during:
1997 – 98 = 5011.8 tonnes
1998 – 99 = 5180.6 tonnes
1999 – 00 = 7466.3 tonnes
and in 2004-2005 the demand will increase and reach up to 9828.7 tonnes.

Potential crop from honey bee culture
Senna produces bright yellow flowers, which attract honey bees. Full blooming occurs 3-4 times a year and partial blooming goes on round the year (except severe winter) which makes round the year food supply for honey bee. The honey is obtain from honey combs have rich in laxative property.

Climatic and Edaphic conditons of Desert
1. Erratic and scanty rainfall and scorching sunlight round the year.
2. Application of fertiliser, pesticides and irrigation is highly risky and deleterious to soil health and disturbs this fragile ecosystem.
3. Frequent drought makes risk in annual crops.

4. Increase cropping on marginal lands causing desertification which is further accelerating by increasing use of tractor in such lands. Use of tractor is also reducing the natural regeneration of the highly useful plants.
5. High wind regime makes drifting of sand from deep sand and sand dunes, which many a time, spoils the productive lands, obstructs rail and road traffic.
6. Economic instability due to drought is a major constraint for development of this region.

Favourable environment conditons for senna

1. Best for good quality as well as quantity of senna.
2. Grow well in rainfed conditions without fertilisers and pesticides. i.e. purely by organic farming.
3. Perennial in nature, deep root system thus least affected by drought.
4.Being perennial, it is sown once in 4-5 years, also least interculture required after establishment, thus both of these environmentally unsafe practices can be avoided.

5. It has deep root system. Quick establishment, and perennial nature provide permanent green cover on sand and thus reduces the sand drift. In other word it could be one of the best plants for sand dune stabilisation.
6. It is a drought resistant, provides income round the year having export value, thus helpful for economic stability.

Senna, which grows in the Rajasthan / Desert have better in the quality as well as quantity point of view.
Tarun Prajapati, AMALTAS