Rice (Oryza sativa L.) is a staple food of nearly half of the worlds population. Rice is the chief food for the world 2.7 billion populations, from which mostly belong to Asia. A normal human body gets 66% of protein and 76% of calories from rice through daily intake of food. Rice provides 20% of the worlds dietary energy supply, while wheat supplies 19% and maize 5%. Rice provides 21% of global human per capita energy and 15% of per capita protein. Rice occupies almost one-fifth of the total land area covered under cereals. Approximately 11% of the worlds arable land is planted to rice annually, and it ranks next to wheat.
Pakistan is the fourth biggest exporter of rice in the world. The crop accounts 2.7 % to the value addition in agriculture and rice GDP share in Pakistan is 0.6 %. There are over 100,000 or more varieties of rice of which some 8,000 are cultivated by man for food.
TYPES OF RICE ON THE BASIS OF NUTRITION LEVEL
1-Brown Rice: Also called cargo rice, as this rice was transported in cargo ships from the Far East to Europe. It has a characteristic beige color and is the most nutritious form of rice; its nutty flavor is rather strong.
2-White Rice: Is brown rice, from which the germ and outer layer of pericap have been removed. It is also called unpolished rice. Its nutrition is lower than brown rice.
With the passage of time a lot of rice types such as basmati, hybrid and coarse rice are being grown. Basmati rice is grown on the 54% area of total rice area in Pakistan, while coarse and hybrid types are being grown on 31% and 15% area, respectively. There is a numerical difference in the inputs and water requirements of different rice types. The net profit obtained from these types is different. The growers only meant to his profit. So they are confused to select a rice type which gives them maximum economic return.
In Pakistan, Basmati rice is characterized by extra long, superfine slender grains having a length to breadth ratio of more than 3.5, sweet taste, soft texture, delicate curvature and an extra elongation with least breadth-wise swelling on cooking. Basmati rice is mostly exported to other countries. The main basmati rice imported countries are Europe, USA and Saudi Arabia etc. its price in market is always higher than other varieties so farmers necessarily grow this type. Basmati rice attains more height, so wind causes lodging of this type. If lodging take place, it severely affect yield. Sometimes yield may reduce from 20 to 40%, if lodging occurred in early stage.
Rice whose kernels length width ratio is less than two is called coarse rice. It is mostly cultivated in Sindh. It is also cultivated in some districts of Punjab. Its fertilizer requirement is more than basmati rice. It takes less time to ripe. Its water requirement is low and we can save water by growing this type. Plants of this type are dwarf naturally, so chances of lodging are very rare. Its yield is intermediate between basmati and coarse type. The rice of this type is mostly exported to Africa, Iran, Saudi Arabia and Afghanistan. After cooking the rice of this type sticks to each other, due to this reason, our people dislike this type. Its price in market is more than hybrid rice and less than basmati rice. Its seed is imported from abroad and prepared in Kala Shah Kaku for general sowing in our climatic condition.
A hybrid is the first generation offspring of a cross between two genetically diverse parents. It is beyond doubt that hybrid rice has the potential to increase yields by 15 to 27 percent as compared to conventionally grown rice varieties It is not alone the yield potential of hybrid rice which induces farmers to grow its varieties but these are the profitability gains from production of hybrid rice that would encourage farmers. Yield potential of hybrid rice varies within, over time and across the countries. For example in China, the hybrid rice yield raised from 3.4 to 6.7 tons per hectare during 1978 to 2008. In another year, 27 percent higher hybrid rice yield has been observed in China. In Bangladesh, yields of hybrids were 14% higher than that of high yield varieties.
Although world rice production has doubled in the past 30 years due to the introduction of superior varieties and better cultivation practices, but it is still unsatisfactory to meet ever increasing global demands. It is not possible to increase the area under rice cultivation because population and urbanization is increasing day by day, and arable land is decreasing. Enhancing the yield per unit land area is the only way to solve food shortage problem. Utilization of hybrid vigor seems to be the best option to ensure food security worldwide. If we replace the 50% area by hybrid rice of the total rice covered area in the world, rice production could be increased by 150 million tons and 400 million more people can be fed.
Constraints in adaptation of hybrid rice
There are several constraints identified in the wider adoption of hybrid rice in spite of higher yield over the existing inbred rice varieties in Asia. It was found that stickiness of cooked rice and its relatively inferior quality in terms of taste were the constraints in hybrid rice adoption. Its market still not developed properly in Pakistan. Its market price is less as compared to other varieties. Farmers have to buy the costly seed every year and that may increase the input cost as compared to conventional rice. Hybrids require more dose of fertilizer. Hybrid seed is not suitable for second crop.
ADVANTAGES OF HYBRIDS
Hybrids have shown their ability to perform better under adverse conditions of drought and salinity. Average yield of hybrid rice is more. Quantity of seed used in hybrid rice is significantly less than the seed used in conventional high yielding varieties. Average productivity and total return to total input cost is relatively higher for hybrid rice than for conventional high yielding varieties. Hybrid rice cultivation is economically viable if management level is above 60 per cent. Hybrids are short duration with resistance to major pests and diseases. Hybrids are non-lodging varieties. Less number of irrigations is required.
We conclude that hybrid rice hybrid rice gives more profit and is also environmental friendly. As hybrid rice is resistant against insect, pest and diseases so no or less need of pesticides. Our rice product will also chemical free. As its mention above that hybrid rice requires less water, there is acute shortage of water in Pakistan, so its our need to grow hybrid rice.