An Essay on Cultivation of Rice for Botany Students

Rice is the important cereal of the world. It included under grass family which produce starchy edible grains. It is an Asiatic crop and extensively cultivated in southern south eastern and eastern Asia. Rice is the second important food crop of man next to wheat. India is the second largest rice producing country in the world. It account for 25% of the total global rice production.

Rice Plant:

Rice plant is named as Oryza sativa, belongs to family Graminae or Poaceae. It is an annual herb, having smooth, hollow erect culms 0.5 to 1.5 meters high and an extensive fibrous root system. Tillers or side shoots arise from the basal node of the main culm. The leaves are borne at an angle on the stem. They have linear blades, sheathing leaf bases and ligules at the junction of blade and sheath.

Flower are small inconspicuous and are borne in a loose terminal panicle of spikeletes. The grain is a simple dry indehiscent one seeded fruit called caryopsis. It remains surrounded by husks and together is called paddy. The husks consist of two empty glumes, a flowering glume or lemma which is often owned and a palaea.

The seed is endospermic. The endosperm is starchy and is covered by a layer of protein the allurone layer. An average inflorescence of rice bears about 100 to 150 grains.

Cultivation of Rice:

De Candolle and watt thought that south India was the place where cultivated rice originated. Vavillo suggested that India and Burma should be regarded as the centers of origin of cultivated rice. Thus it indicates that there might have been two centers of origin of our cultivated rice, if south-eastern Asia India, Burma and Thailand and West Africa.

The paddy crop is cultivated almost in all the states of the country Orissa, Andhra Pradesh, West Bengal, Bihar, Uttar Pradesh, Madhya Pradesh and Tamilnadu are the leading rice growing states.

i. Climatic condition for rice cultivation:

Rice is water loving plant which is grown in north-eastern states, all rounds the year if water is available either though rain or irrigation.

Rice needs relatively high temperature ranging between for optimum growth and development of plants. Depending upon the temperature requirement rice crops grown during kharif.

ii. Soil type required:

Rice is grown on all sorts of heavy soil type’s clay loamy of alluviuol in nature, which have high water holding capacity.

Cultivation of rice completely depends on the availability of water. Depending on the amount of rainfall and irrigation facilities various methods are adopted as follows.

Methods of Cultivation:

There are two distinct methods of cultivation of rice have been adopted all over.

Broadcasting Method:

This is the principal system of rice cultivation in India which is done in the process of dry or semidry method. It involves following steps.

i. Land preparation:

Under dry cultivation system the land is ploughed immediately after harvesting the previous crop. The soil is ploughed 10-20 cms. Deep land is leveled leveling board or ladder. This ploughing is done before the arrival of first monsoon. Ploghing is done 3-4 times at intervals.

ii. Sowing or broadcasting:

After first rainfall or partial irrigation the land again ploughed before sowing. Sowing is done under moist condition immediate after final ploughing. Then the land again leveled.

Treatments:

Germination of seeds over after getting sufficient moisture. When the seeding are 20-25 cm high and sufficient water is available, i.e. under water logged condition the field is lightly ploughed which called as beushana. Then the plants are allowed to revive and grow. Manuring is done before Beushan. During tillering calculated amount of fertilizers applied for good tillering and growth. Sufficient water should be stored in field during growth. The crop comes to the flowering stage after 60-70 days of last treat.

Transplantation Method:

This method is extensively used in the areas where rainfall is much. In this method separate seed beds are prepared to raise seedlings and then the seedlings are transplanted on the field. This included following steps.

i. Nursery raising of seedlings:

Land is ploughed in wet condition or dry moist condition. It wet nursery Ploghing is done on standing water. Some countries also adopted ‘Dapog’ nursery or transpertable nursery. In above cases a perfect seed bed is prepared with applying requisite manure, cow dung and fertilizers. Seeds are sown on the surface densely. Then the seeds germinate on getting sufficient moisture then the water logging is avoided in seedbed.

ii. Field preparation:

For transplantation method, ploughing is done on standing water in the field. The field is puddled properly by taking all the nutrient or manuring measures. Formyard manure compost oil cakes tank slit fish manure green twig NPK fertilizers are commonly used during field preparation.

iii. Transplanting:

In case of kharif crop transplantation is done when seedlings attains 20-25 days of age where as in case of rabi crop transplantation is done when seedlings are of 30-40 days.

Seedlings are pulled out with base, and made into bundles suitable sanitation is maintained. Two or three seedlings together are planted at spacing of 20*10 cm or 20*15 cm. Closure planting may be done if the plantation is late.

Until the transplanted seeding are well established water is allowed to stand in the field to a depth of 1/3 to 1. Then the water is allowed to stand about 2-3 depth. Then the crop is allowed to grow.

Harvesting and Threshing:

Field is allowed to dry up just before the harvesting. Harvesting should be done in time to check grain sheeding. Early and medium varieties should be harvested 25-30 days after flowering while in late varieties it is after 35-40 days. At the time of harvest the ears should be ripe and straw as slightly green.

The plants are cut by sickles and collected in bundles then completely dried crop taken and stocked in the threshing ground. Threshing can be done after two – three weeks of harvest, by beating manually or using the mechanical thresher or by trampling them by bullock’s feet. The grains are collected after removal of chaps, by air blow method.

Then the paddy is ready for storage or grain processing. Grain processing or milling cab be directly done to obtain the rice grain or may be parboiled, sun dried and then milled.

Important Varieties of Rice:

i. Early sarad – Ratna, padma, parijata, sulphla.

ii. Medium sarad – hema, rajeswari, jaya, sakti.

iii. Early daluo – pusa 2 -21, bala, cauvery, parijata.

iv. Medium daluo – tatna, supriya, Krishna.

v. Biali (Early) – pusa 2-21, bala, cauvery, parijata.

vi. Resistant verity – jagannath, IR-8

vii. Draught resistance – liran, kanchan, bhavani, bala, CR 143-2-2

viii. Disease resistant – CO14, K333, 1242, 4141, IET TMK-6 etc.