The following points highlight the four important oil yielding plants of India. The oil yielding plants are: 1. Mustard 2. Coconut 3. Ground Nut 4. Linseed.
Oil Yielding Plant # 1. Mustard (Brassica Campestris Linn):
Mustard is a tall herbs, a metre high or more, with pungent juice. Leaves are large alternate, lyrate, rounded at apex; petiole stem clasping, the upper usually auricled, 10-25 cm. long, 5-10 cm. broad. Inflorescence a raceme or panicle.
Flowers actinomorphic, hermaphrodite hypogynous Sepals 4, imbricate, pouched at the base. Petals 4, set crosswise, distinctly clawed, yellow. Stamens 6, tetradynamous; filaments of inner 4 stamens longer than the outer 2; anthers oblong, basifixed.
Carpels 2; ovary superior, 2-celled by a placental replum; style beaked, stigma 2-lobed; ovules many, on opposite sides of the replum on 2 parietal placentas. Fruit an elongated capsule with a seedless indehiscent beak at the apex; valves deciduous, replum and placentas persistent; in cultivated forms valves often more than 2. Seeds globose, with large cotyledons.
Different varieties of the above species are cultivated in India, viz. B. campestris (1) var. sarson Prain, (2) var. toria Duthie & Fuller, (3) var. dichotoma Watt., etc. Besides this 2 other species are also cultivated, viz. B. juncea Czern & Cess and B. nigra Koch. A great diversity of forms is met with in the varieties of B. campestris.
In var. sarson the ripe fruits are erect in some and directed downwards in others. The number of valves in a pod and the colour of seeds also vary. In case of vartoria the plants have a more open habit with many dichotomous branches and stem-clasping leaves.
The pods are torulose and the seeds are bluish brown and finely rugose. The variety dichotoma is more or less like var. toria and has the seeds with a mucilaginous coat. B. juncea is the Rai-sarisha the seeds of which are yellow. B. nigra has almost back seeds which are usually used to flavour curries.
Mustard is grown as a winter crop. It requires a loam soil prepared by 2-3 ploughings. Seeds are scattered or sown by seed driller. It is usually grown in rain-fed areas in Himachal Pradesh to Bengal with plenty of moisture in the soil while in some parts of Uttar Pradesh it is cultivated in irrigated fields.
Seeds are sown in Sept-Oct. and the crop is ready for harvesting in Jan-Feb. No manuring is usually applied; it has however been observed that 15 kg. of ammonium sulphate per acre increases the yield. Mustard is grown as a pure crop or mixed with pea, wheat or barley.
While harvesting the whole plants or the top portions only are collected before the pods dehisce. These are carried to the threshing floor and left for 2-3 days. The seeds are then separated by beating by sticks or under the feet of goats. The yield per acre varies from 400-700 kg.
Oil Yielding Plant # 2. Coconut (Cocos Nucifera Linn):
Coconut is a tall palm with an un-branched trunk, up to 25 m. high, with a crown of long feathery leaves; base usually swollen. Leaves are pinnate, 2-4 m. long; leaflets equidistant, up to a mtr. long, linear lanceolate.
Inflorescence a branched spadix about a mtr. long, axillary, erect but ultimately drooping, flowers small, unisexual; female flowers scattered near the base of the branches of the panicle, often between 2 males, the upper portion of the branches having male flowers only.
Male flowers unsymmetrical, with 2 series of perianth. Perianth segments 3 in each series, coriaceous, 2-5 mm. long, valvate. Stamens 6, filaments short, anthers linear. Perianth segments of female flowers about 1.2 cm. long, persistent, inbricate. Carpels 3, connate in 3-celled, superior ovary, ovules solitary, basal; style short; stigmas 3, recurved.
Fruit a large drupe, 20-30 cm. long, ovoid, trigonous or almost terete, 1-seeded, with a thick fibrous pericarp and hard endocarp with 3 basal eyes, the remains of 3 ovarian cells. Embryo lying opposite to one basal eye, embedded in the fleshy endosperm lining the endocarp with a fluid filling the central portion.
No other plant appears to be more important economically than the coconut palm. Besides the “copra” or the kernel which is an article of food and is the source of the oil, the fruit is in great demand for the milk of green coconut which furnishes a cool and refreshing drink.
The fibre of the husk of the fruit is also an important article of trade for the manufacture of matting, brushes, ropes, etc. The other parts of the tree are also used in various ways often in different ailments. The coconut palm is cosmopolitan in the tropics but not found inland far from the sea. Probably it originated in the western parts of tropical America or in the ancient land of Papua.
The fibrous coat helped the fruit to float and to be carried to distant countries adjoining the sea. It reached Africa very recently and also to West Indies although it was growing all the time on western parts of America.
It came to India in the remote past either by human agency or by ocean currents and established in the costal districts of Peninsular India. It is in Kerala and Tamil Nadu that there are some plantations; in other states Coconut is cultivated in village orchards with other fruits and such states are Maharashtra, Karnataka, Andhra Pradesh, Orissa and W. Bengal.
Coconut prefers a typical tropical climate, hot and humid. Soil must be well drained. Light ‘alluvial sandy soil near the coast is ideal for coconut growing. Rainfall of 1250-1750 mm. well distributed throughout the year favours healthy growth of the plant. It can stand much higher rain fall if the soil is well drained. Where rainfall is lower than 1000 mm. per year irrigation is necessary. Plenty of sunlight is necessary at all stages.
Seedlings are raised in nurseries where the soil should be sandy or light loamy. Seed beds are long and narrow, raised 20-25 cm. above general ground level. Beds are 25-30 cm. apart and the nuts are placed with same spacing. Shallow drains are made between, the beds.
Seedlings are fit for transplanting after 7-8 months. Pits should be dug 1 × 1 × 1 mtr. in rows, 3 mtr. spacing between pits in the rows and 8-10 mtr. between the rows, so that a field of 1 acre can accommodate 40-50 plants, or if the soil is rich the rows can be made closer increasing the number of plants per acre. Sometimes triangular planting is done to have more plants in the field.
Watering in the dry seasons is necessary for 2-5 years planting. Cereals, pulses or herbs with underground tubers are often grown in the spaces between rows as inter crops. Bananas and pineapple are also cultivated.
Crotalaria and Tephrosia are often grown as cover crops that are used for green manuring and also for checking other undesirable weeds’. Artificial fertilizers are seldom applied but wood ash, cattle manure and oil cake are recommended at the rate of 10 kg. per palm per year.
Plants begin to yield 5-6 years after planting. A mature tree gives 60-100 nuts per year in 6-8 gatherings. Sometimes much damage is done to the trees by beetles. These are to be collected and destroyed and the decaying refuse in the field that serve as the breeding medium should be burned.
The fruits are sundried or kiln dried. Dehusking is done with manual labour. Dehusked nuts are broken into 2 halves and these are again dried in sun or over fire when the meat or the kernel shrinks and is easily detached from the shell.
The meat is further dried. Oil is then extracted from the dried meat or copra by pressing in bullock-driven ghanis or in rotary ghanis or expellers and hydraulic presses. The copra contains 57-757o of oil. The oil serves as an edible oil, hair oil, an ingredient in soap manufacture, a constituent of margarine, a base of pharmaceutical ointment and also as a substitute of ghee. The cake is a cattle-feed and also a fertiliser.
The coir is the fibrous element of the husk and is used in making ropes and matting and in stuffing cushions. A sugary juice in copious quantity exudes from the stalk of the young inflorescence when the upper portion is chopped off and this is made into toddy and jaggery.
Oil Yielding Plant # 3. Ground Nut (Arachis Hypogea Linn):
ground nut is an annual herb, with erect stem and branches, or branches prostrate. Leaves are even pinnate with 2 pairs of leaflets; stipules adnate to the petiole; leaflets rounded or acute at apex, 2-3 cm. long. Spikes axillary, near the base of the stem and branches, or flowers solitary, often from underground stem.
Flowers bisexual, zygomorphic, hypogynous 1 cm. long. Calyx of 5 sepals, united in a slender tube with 2 lips; the upper 4-lobed, the lower with 1 lobe membranous. Corolla of 5 yellow petals, papilionaceous; standard petal or bicular; wings oblong, free; keel incurved beaked. Stamens 10; filaments connate in a tube alternately long and short.
Ovary superior, monocarpellary; ovules 2- 3, marginal; style long, filiform, with a small stigma; the receptacle elongating after fertilisation, becoming reflexed and burying the fruit underground; fruit an oblong lomentum, more or less torulose, continuous within, 1-3-seeded, ripening underground. Seeds ovoid, slightly depressed at one side at base, with a brown testa.
The ground nut originally came from Brazil. It is now cultivated in all tropical and subtropical countries and in a large scale in India, China, U.S.A. and W. Africa. To India it was introduced in the 16th century and at present the total production of nuts in India exceeds 400000 (four lacs) tons being 35% of the world total.
The plant has about 100 cultivated varieties or forms which however are commonly divided into 2 groups or types:
(1) The bunch — or erect-type and
(2) The runner or spreading type.
In the former several branches come up from the base of the main stem and grow erect. These branches bear clusters of flowers at the base. The fruits are smaller, thin shelled and with rounded seeds. Plants of this type come to flower in 3-4 months. The spreading type has long creeping branches flowering along their length. The fruits are longer with thicker shell. These plants come to flower in 4-6 months’ time.
The plants are grown in sandy or loamy soil, or in black soil, but grow best in light sandy loam soil. It is grown as a rain-fed monsoon crop. In some places it is grown in irrigated fields.
The land is prepared by 2-4 ploughings, and the seeds are sown by dribbling method in the furrows. Spacing is about 30 cm. between rows and 25 cm. between the plants. In rich soil wider spacing is necessary. Two hoeing’s and weeding are practiced, one 3-4 weeks after sowing and a second time after another month.
No fertilizer is given but just before sowing time 2-5 tons of cattle manure per acre is often applied. On sandy soil tank-or channel-silt, 15-20 tons per acre is recommended. Ground nut cultivation enriches the soil with respect to nitrogen.
Seeds are sown in February-March after a shower and the crop is harvested in June to August. Bunch type plants are lifted by working a harrow or by using a hand hoe. The fruits are removed by hand or by beating the plants against a bar.
In the case of spreading type the field is dug up with spades, ploughed or harrowed and the pods are hand-picked. The pods are then dried. The dried pods are shelled by beating with sticks or by machinery.
The seeds are pressed to obtain the oil which edible as such, or by hydrogenation is converted to vegetable ghee. The oil is often used as a substitute for diesel. It is used in soap manufacture, in cosmetics, leather dressing and as tallow substitutes.
The yield of oil is 36 – 40% of the seed. Peanut butter is also prepared from the seeds which is used as a substitute of butter or is mixed with butter. Pea nut flour is also made which is used as wheat flour. The oil cake of groundnut is an important cattle feed. It is also a valuable organic manure.
Oil Yielding Plant # 4. Linseed (Linum Usitatissimum Linn):
Linseed are herbs. 60 – 120 cm. or taller. Leaves are simple, narrowly linear, entire 3-5 cm. long; stipules are replaced by glands. Flowers few at the end of the branches near the top of the stem, regular and hermaphrodite.
Sepals 5, white — margined. Petals 5, contorted, obovate, 1-1.5 cm. long, blue, pale purple or white. Stamens 5, alternating with small staminodes; filaments connate below; anthers versatile. Ovary superior, 5 locular, each locule again 2-locullate; styles 5, free, with clavate stigma; ovule one in each locule.
Fruit a 5-celled capsule, slightly exceeding the sepals, splitting into 5 2-seeded or 10 1-seeded cocci. Seeds narrowly ovate, compressed, more or less shining, about 0.5 cm. long with scanty endosperm and-straight embryo.
This species is not found wild in any part of the world although it has been in cultivation in the Mediterranean region since antiquity. It is very close to Linum trienne Mill, growing wild in S. Europe and is considered to have been derived from the latter species.
Those growing in S. Europe and N. Africa are tall plants and yield the “flax”. The oil content in the seeds of these plants is scanty. The oil yielding variety is cultivated in Turkistan, Afghanistan and India.
This variety has shorter stem, much branched and is tillering. Oil content in the seeds much higher. In India it has been introduced from Central Asia. In S. Russia and Asia Minor transitional forms are grown that give fibre as well as oil seeds.
In India two distinct types are cultivated viz. the Gangetic type of N. India and the peninsular type of Rajasthan and Central India. The former has a shallow tap root, is slow growing and late maturing but produces much more fruits and seeds. The other has a long tap root, quick growing early maturing with larger seeds rich in oil but production of fruits and seeds is low.
Linseed plant is grown as a pure or a mixed crop. Almost all types of soil having sufficient moisture are suitable for growing Linum. Black soil and heavy soil of central and Peninsular India are equally good for linseed growing.
In northern India it is grown chiefly in the submontane districts and does best on heavy loam soil. Areas with moderate rain-fall of 75 -175 cm. per annum appears to be best suited for linseed growing. In northern India it is grown in the cold season.
Seeds are sown in November and the crop is harvested in March-April. In the hilly districts of Uttar Pradesh seeds are sown in Sept-Oct. In Kashmir seeds are sown in Feb-March. In Peninsular India seeds are sown in Sept-Oct. and the crop is harvested in February.
Seeds are swoon in lines and the lines are about 30 cm. apart. In case of growing as a mixed crop where there are standing crops in the field seeds are sown by broadcasting. Nitrogenous fertilizer increases the yield of seeds.
The crop is harvested when the capsule matures but before it dries up and splits. The plants are cut close to the ground or are uprooted. They are left in the field to dry and then threshed. The chaffs are separated from the seeds by winnowing.
Threshing is done by beating with sticks or wooden mallets or by hand driven deseeding machines. The stems are collected and treated for the extraction of fibres. India produces about 150,000 tons of linseed oil all of which is used internally.
The demand of linseed oil is mainly for the manufacture of paints and varnishes. It is also used in the manufacture of linoleum and oil cloth, printing and lithographic ink and soft soap. It has a medicinal value and is laxative.
Linseed cake is used as a nutritive food, as a protein supplement to live stocks. For dairy cattle and young stocks it is very valuable. It is also used as an organic manure. The mucilage from the seeds or from the cakes is used in cosmetics and in pharmaceutical industries.
Flax is obtained from stalks of the plants grown especially for this. These plants are harvested when the capsules are still immature. Flax fibre is woven into different types of fine fabrics as well as canvas, buckram etc. Strong ropes and twine threads are also manufactured from flax.
Linseed fibre is obtained also from types that are grown for oil seeds. These fibres are extracted from the straw after the seeds are collected. Linseed fibre is also spun into fine or course yarn. It is inferior to flax but is strong.
It may be spun into textile by itself or mixed with cotton or wool. This fibre is very suitable for making paper pulp. Linseed straw is also useful. It is used in the manufacture of card board arid wrapping and insulating material.