Abstract:
Rice. (Oryza sativa L.) is the. second most important crop of the world. More than 90% of world rice production is from Asia. India has world s largest growing area with about 43 million ha. In terms of importance of food crop rice provide more calories per ha than any other cereal crops. It is estimated that 40% of the world population use rice as major source of calories. The biomass produce of rice is not only used as food grain but also used as fodder, fuel and fiber. To meet the ever-increasing demand of food, fodder, fuel, and fiber the growth rate of rice production has to be increased to maintain self-sufficiency through intensive cultivation and introducing hybrid varieties. At present India has also entered era of hybrid rice.
Rice cultivation in the world extends from 390 S latitude (Australia) to 50° N latitude China. In India it stretches from 8 ON latitude to 34 ON latitude. Rice is also grown even in area below sea level as in Kuttanad region of Kerala. The highest altitude at which rice is grown is in Nepal's Jumla vally in the far western Himalayan. Rice seedling from the nursery bed can be transplanted to the field when the mean daily temperature is about 13-15° C. Weather variables affect the crop growth differently in different phenophases during its growth....
