Many plants are economically important and useful to mankind in several ways. Based on their utility, they are broadly classified as food plants, fibre plants, oil plants and timber plants. Now, we will discuss some of the economically important plants for each category.
Its binomial is Oryza sativa. It belongs to Poaceae. It is the most important cereal of tropical climate. This plant is an annual grass. The inflorescence is panicle containing a number of branches, each terminating in a single grain. IR - 8, ponni, kannagi, kavery, ganga, etc. are some of the recent varieties cultivated in India.
Rice is the chief source of carbohydrates. Polished rice is less nutritive.
Straw is used as livestock feed. In Japan, alcoholic beverages are also distilled from the grains of rice. Recently, from the husk of paddy, a cooking (rice bran oil) oil is extracted. Now, bio-diesel is obtained from rice bran oil.
Rice is the major food of half of the world's population. Particularly in the eastern hemisphere it is the staple food. Rice cultivation is the only source of income for majority of people in our country. The uses of rice are many.
x Parched rice (pori) is crisp to eat. It is sold either salted or unsalted.
x The flattened parboiled rice is known as flaked rice. Like corn flakes, it is a very good break fast food. Flaked rice is also used for prepar-ing different kinds of food items.
x Sake is an important alcoholic beverage in Japan. Sake is prepared by the fermentation of rice.
x Bran is an important by-product of rice milling industry. It is used as a cattle feed.
x Bran oil is extracted either by expression in a hydraulic press or extra-ction with solvents. Bran oil is used as edible oil and for preparation of vanaspathi, making soaps. It is also used in the textile industry, leather industry.
x Bran wax is a by-product in bran-oil extraction. It is used in chocolate industry and in the manufacture of lip-sticks.
x Paddy husk is used as fuel, in brick kilns. It is also used in brick making.
x Straw is used as cattle feed, in the manufacture of straw-boards and for making hats, ropes, mats, etc.
Its binomial is Arachis hypogea. It belongs to Fabaceae. It is an annual. The word groundnut derives its name from the fact that its fruits ripe beneath the ground.
The roasted seeds are edible. Oil is extracted from the seeds and used as fine cooking medium. Vegetable ghee (peanut butter) is also prepared from this oil. The oil cake is fed to the livestock. It is rich in fatty acids and proteins.
x Groundnut oil is one of the important edible oils. It is extensively used in cookery as a salad oil. It is used for the manufacture of vanaspathi.
x Groundnut kernel is rich and cheap source of vegetable protein. Kernels are eaten, fried and salted and added to a number of dishes.
x Peanut butter is prepared by grinding roasted and blanched kernels.
x It is nutritious.
x Groundnut oil is used to a limited extent in soap making.
x Oil is used as illuminant, lubricant.
x Oil cake is used as animal feed and organic manure.
x Groundnut shell is used in the manufacture of activated carbon.
x The groundnut cake is a good cattle feed. The plant after removing the pod, both dried and fresh is a good cattle feed.
Many members of Malvaceae yield fibres. Gossypium barbadense
(Egyptian cotton) and G. hirsutum are some examples for fibre plants.
The seed coat of cotton seeds produce fibres on their external surface. So, it is called as surface fibre.
Almost the entire textile industry depends on this fibre. Cotton is used in stuffing the pillows and cushions. It is also used in making rubber tyres, carpets, blankets and cordages are made from cotton.
3. It is a cash crop.
4. It gives three important products: fibre, food and cattle feed.
5. Lint fibre is for clothing which is very much useful in the textile industries.
6. Seed is used for extracting oil. This is also used as vanaspathi.
7. Cotton flour prepared from the seed is used for bread and biscuit making.
8. Cotton seed cake is used as a good organic manure.
9. Fatty acids obtained from oil is used in the preparation of insecticide, fungicidies and plastics, etc.
Its binomial is Tectona grandis. It belongs to Verbenaceae. It is large deciduous tree and shows resistance to termites. Sap wood is white and heart wood is green emitting fragrance. The timber retains its fragrance for a long time. It is hard , durable and strong and also takes up good polishing.
In India, it is used for making furnitures, buildings, cardboards, railway sleepers, etc. Ships and bridges are also made from this timber.
x Teak wood is durable and it is an important timber in the tropics. As the seasoned teak, timber does not shrink, crack or alter its shape, it is extensively used in making household furnitures.
x It is also used in ship building, boats, etc.
x It is used for interior decoration.
x It is used for the manufacture of boards.