Area & Distribution
Area : India > China > Indonesia
Production : China > India > Indonesia
Productivity: USA > Japan > China
In India
Area : West Bengal > UP > Bihar
Production : West Bengal > UP > Andhra Pradesh
Productivity : Punjab (34 q/ha).
• Maximum area under rice is in Asia.
• Among the rice growing countries, India has the maximum area followed by China and Bangladesh.
• In the respect of production, China (144 million tonnes) first followed by India (69 million tonnes).
• Korea Republic rank first in average yield per hectare followed by Japan.
Classification
Oryza sativa is a diploid species having 24 chromosomes.
The sativa rice varieties of the world commonly divided into three sub-species
(i) Indica Rice: Rice grown in India belongs to the Indica sub-species. It is awnless.
(ii) Japonica Rice: The varieties developed in Japan belong to this sub-species suitable for sub tropical and warm temperature regions.
(iii) Javanica Rice: These sub-species are found mainly in Indonesia. It is awned grain, sparse tillering habit.
Test weight (wt. of 1000 grains) is = 25g
Rice stem is commonly called the haulm or culm which up of a series of nodes & internodes.
Inflorescence of rice is panicle which is a group of spikeleL
Climate and Soil
Climate: C3, short day plant and required hot & humid climate.
Rice crop needs a hot and humid climate.
The average temperature required throughout the life period of the crop ranges from 21-370C.
Temperature requirement for blooming in rice.is the range of 28.5-29.50C. Rice is a Short day plant,
Soil: clay and clay loam are best suited for rice cultivation.
Acidic soils are good for cultivation, most suitable pH range is 4-6.
Seasons
Aus: Sowing time April-May.
Aman (Kharif): Sowing time June-July.
Boro (spring): Sowing time November – December.
In North-West part of counüy only kharif crop is taken due to falling of temperatue in winter.
Seed Rate and Sowing
100 kg (about) seed/hectare used in the case of broadcasting of seed.
About 60 kg seed is suffcient for one hectare in the case of drilling method.
Total quantity of phosphorus and potash and 25% of total nitrogen should be drilled in the sail at the time of land preparation After 35-40 days of sowing or at tillering stage, top dress 50% of total nitrogen. The remaining 25% nitrogen should be top dressed at panicle initiation stage. For transplanting one hectare area required about 500 sq m area for nursery raising.
Broadcasting: 100 kg/ha
Drilling: 60 kg/ha
Hybrid rice: 15 kg/ha
Dapog method: 1.5-3 kg/ha
R X P distance: 20 x 10 cm.
Dapog Method of Rice Cultivation
This method of raising nursery has been introduced India from Philippines. 25-30 sq m of area is enough to raise seedlings for planting one hectare land.
Dapog seedlings would be ready for transplanting within 11-14 days of sowing.
Varieties
Imprtant varieties of rice are given below
In direct, seeded upland condition, an early maturing variety of 100-105 days duration such as Govind, Bala, Cavery, Pusa 2-21 and Nagina-22 should be selected.
In direct puddled field, varieties of 115-125 days duration like Saket-4, Ratna IR-24 should be selected.
Rice varieties such as IR-20 and Govind are tolerant to bacterial of paddy.
Saket-4 and Prasad are moderately tolerant to blan disease of paddy.
Madhukar and Chakia•59 is recommended in standing water upto the level of 120 cm and that of Jal Magan in standing water upto even 3-4 m.
Jagannath is a dwarf mutant varieties of T-41.
Diseases
• Blast Disease
Caused by Pyricularia oryzae.
• Bacterial Leaf Blight
Caused by Xanthomonas oryzae.
• Bacterial Leaf Streak
Caused by Xanthomonas translucens f. sp. oryzicola.
Tungro Virus
This disease is caused by virus. Virus is transmitted from diseased plant to healthy plant by the nymph, male and female of rice green leaf hoppers.
• Khaira Disease
Caused by zinc deficiency and growth of diseased plant is stunted.
Insects and Pests
(i) Rice Hispa
The adults of this insect on upper surface of leaf blade, leaving only lower epidermis.
(ii) Gundhi Bug
Both nymphs and adults cause damage by sucking the plant sap. It produces unpleasant smell’ when touched or disturbed.
(iii) Green Leaf Hopper
Sogatella furcifera It also transmits tungro virus disease other plant hoppers mole cricket, leaf roller etc.