User:Manjuanandilal/Plant Science in Ancient India

 Plant Science in Ancient India

Since time immemorial, people have been interested in knowing about plants. In India also, the history of plant science has been very old-mainly because of their medicinal values. From the time of Indus Valley civilization, lots of evidences unearthed, have indicated the importance of agriculture at that time. Plants formed the important part of daily life during vedic times. Various observations are made, where there are number of prayers, involving the gods for the growth and development of plants. The following extract from Rigveda indicates that the fundamental principles of farming were realized and adhered to,

‘’Harness the ploughs, fit on the yokes, now that the womb of the earth is ready, sow the seeds therein, and through our praise may there be abundant food; may (grain) fall ripe towards the sickle.’’

Agriculture was considered to be the occupation of well trained persons, which required special bent of mind and not for the fool of the family. In Arthas’stra these agriculturist have been called as supritendent of agriculture i.e., Sitadhyaksh, who should be well informed about the soil type and propagation methods. People adopting agriculture were required to possess the knowledge of seed sowing time, soil type and also the methods of plant propagation.

The plants were considered as living beings like the animals and human beings, as is evident by a number of references available which show that ancients speculated analogy of morphology, anatomy and physiology between plants and human beings. In Shantparva of Mahabharata, it is written, ‘as the man sucks water upwards with help of lotus petiole, trees drink water through the roots with the help of air’ indicate knowledge of ancients about transpiration process. In Rigveda a verse has been addressed to plants, which indicated that the plants have the sense of hearing. Rigveda refers that ‘trees suffer pain from the axes’, indicating the awareness of vedic people about the living nature of plants.

Not only this, a verse from Rigveda shows the awareness of the ancients about the process of photosynthesis in plants, which says, ‘'O! Sun, you fix Harinam air in trees, which comes out as a result of my breathing out. Thus you will fill Vanaspati with green sap with the help of my Harinam air.’'

In Sushruta samhita, soil has been classified in sis different types on the basis of colour, texture and growth of plants. In Matsya Puran, methods have been suggested to test the soil for suitability for cultivation of crops. Various references indicate that the ancients may not be aware of exact chemical composition, but they made extensive experimental observations regarding characteristic suitability for cultivation of different kinds of crops.

Soil was well prepared before sowing of seeds. As is quoted in Brihat-samhita that '''pre-treatment of soil is necessary before sowing of seeds. It is suggested that sesmum should be grown and crushed while in bloom'''. Immediate sowing of seeds should be followed. As we know that '''sesamum is the plant with extensive root system and it grows deep in the soil using even the sub-soil nutrients. It is considered to be an exhaustive crop. Roots of the plant are the most important source of organic matter. These penetrate deep to considerable depth and decay year after year, and in course of time leave great source of organic matter to be broken down. Since sesamum roots retrieve nutrients from deep in the soil, these can be excellent source of nutrients.''' Besides, this will supply the soil with succulent organic matter at the peak of its nutritional benefit. Since the crushing of sesamum is recommended while in bloom, the young succulent material decomposes more rapidly than the older plants. Immediate sowing is recommended following this treatment of soil, so that the nutrients may not be lost either by leaching or by escaping into the air in the form of gas.

Ancients repeatedly laid the stress the importance of plant nutrition. As is quoted from Upavanavinoda that, ‘Trees do not produce flowers merely for being planted’, so one is required to possess the knowledge of plant nutrition.

Various symptoms of plant diseases were carefully studied and remedies were given accordingly. Use of milk, honey, decoction of sesamum etc. were highly recommended both for luxuriant growth and also for the flowering and fruiting of trees.

Factors, which are necessary for seed germination, were also understood by the ancients. As is quoted in Sustruta-samhita, requirement of proper season, soil, water and good quality of seeds has been stressed. Stress has been laid for the seeds, that have been ripened in proper season, should be extracted from the fruit, or ‘ripened in full times.’ Even sowing of different seeds in specified conditions has been recommended, like wheat should be sown in somewhat dry field and barley in a wet field. If there is heavy rain, the sowing of chickpea is recommended.

Use of honey has been repeatedly advised. Plant propagation by vegetative means, such as by using cuttings, has also been recommended. The cutting should be smeared in honey along with other constituents. As we know that honey has been called as nature’s most perfect food. Besides presence of various sugars and mineral, acids, a number of other substances are believed to be present. It 'has been found to have antibacterial property and has lately been found to be promoting rooting in Chrysanthemum & Thuja''. Honey has been found to have same effect as by NAA (a rooting hormone), in formation of more roots as well as in the increase in root length. It is also speculated that plant hormones may be present in honey.''' However, this needs to be verified.

Various treatments were also suggested which led to produce marvelous effects, such as inducing flowering out of season, to get the seedless fruits, delaying ripening of fruits or to produce dwarf trees which bears flowers and fruits also.

Treatment for producing seedless fruits included application of paste made of sugars and other material to the roots of the plant, removal of bark of the tree to make a hole through which honey and paste of certain flowers was fed.

Whatever the cause of producing seedless fruits may be, the example clearly indicates the awareness of the ancients about their knowledge of existence of seedless fruits and also about various experimental techniques to produce them. With the present knowledge we know that parthenocarpy has been observed to be induced by excessively rich soil, low carbohydrate and nitrogen reserves or by high and low temperature, besides by application of plant growth hormones.

From the above text, it is evident that the Indians were not only aware of the various plant processes, but they also made extensive experimentation to get the desired results, the details of many of which are still to be investigated.