Hybrid rice technology for food security in the world

L. Yuan
China National Hybrid Rice Research and Development Center, Hunan, China

The current world population exceeds 6 billion and will reach 8 billion in 2030. Meanwhile, the annual loss of land to other uses is between 10 and 35 million ha, with half of this lost land coming from cropland. In the face of such severe population growth pressure plus cropland reduction, it is obvious that the only way to solve the food shortage problem is to greatly enhance the yield level of food crops per unit land area through the advance of science and technology.

Rice is a main food crop. It feeds more than half the world population. It has been estimated that the world will have to produce 60 percent more rice by 2030 than it produced in 1995. Therefore, the increase in rice production plays a very important role in food security and poverty alleviation. Theoretically, rice still has great yield potential to be tapped and there are many ways to raise rice yield, for example, by building irrigation works, improving soil conditions and cultural techniques, and breeding high-yielding varieties. At present, the most effective and economic route available seems to be the development of hybrid varieties based on the successful experience of China.

For many years there has been evidence that hybrid rice has a more than 20 percent yield advantage over improved inbred varieties. In recent years, hybrid rice has covered 50 percent (15 million ha) of the total rice area in China. The nationwide average yield of hybrid rice is 7 tonnes/ha - about 1.4 tonnes/ha higher than that of inbred varieties (5.6 tonnes/ha). Thanks to the yearly increase in paddy in China from growing hybrid rice, it is possible to feed 60 million people each year. Therefore, hybrid rice has been playing a critical role in solving the food problem of China, making China the largest food self-sufficient country in the world.

China continues to make progress in the development of hybrid rice technology. Following the success of three-line hybrid rice in the 1970s, two-line hybrid rice was successfully commercialized in 1995; the extension of two-line hybrid rice has been very fast. The area of two-line hybrid rice was 2.6 million ha (18 percent of the total hybrid rice area) in 2002. The yield advantage of two-line hybrid rice is 5 to 10 percent higher than that of the existing three-line hybrid rice.

More encouragingly, good results have been achieved in developing super hybrid rice varieties since the initiation of the super rice research programme in 1996. Several pioneer super hybrids have a yield advantage of around 20 percent over current three-line hybrids on a commercial scale. The area planted to super hybrid rice was 240 000 ha and the average yield was 9.6 tonnes/ha in 2000. The area under super hybrid rice was increased to 1.4 million ha with an average yield of 9.1 tonnes/ha in 2002. In addition, a two-line super hybrid P64S/E32 and a three-line super hybrid II-32A/Ming86 created, respectively, a record yield of 17.1 tonnes/ha in 1999 and 17.95 tonnes/ha in 2001. In the meantime, the grain quality of the super hybrid rice varieties is very good. Now efforts are focused on developing second generation super hybrid rice. Its yield target is 12 tonnes/ha on a large scale and good progress has been made. Last year there were five locations with 7 ha each in Hunan Province, where the average yield was over 12 tonnes/ha. Therefore, super hybrid rice shows a very bright future. If super hybrid rice covers an annual area of 13 million ha in China, and calculating a yield increase of 2.25 tonnes/ha, it can be expected that the annual increased grains will reach 30 million tonnes, which means 75 million more people can be fed every year.

Hybrid rice has proved a very effective approach to greatly increasing yield, not only in, but also outside, China. Viet Nam and India have been commercializing hybrid rice for years. Last year, about 600 000 ha were covered with rice hybrids in Viet Nam. On average, the yield of rice hybrids is 6.3 tonnes/ha while that of the inbred varieties is 4.5 tonnes/ha. Since it began planting hybrid rice in large-scale commercial productions, Viet Nam has become the second largest rice-exporting country in Asia. Furthermore, many other countries, such as the Philippines, Bangladesh, Indonesia, Pakistan, Ecuador, Guinea and the United States of America, have also made great progress in extending hybrid rice technology. Recently, a number of experimental trials and large-scale demonstrations in farmers' fields conducted in these countries showed that hybrid rice can significantly outyield local CK varieties. For example, in the Philippines, with technical assistance from FAO, the International Rice Research Institute (IRRI) and the China National Hybrid Research and Development Center, hybrid rice was commercialized 2 years ago. In particular, a super hybrid rice variety called SL-8 was developed in the Philippines;^[6] it was planted to about 3 000 ha in 2003 and the average yield was 8.5 tonnes/ha -more than double the country's average yield. On the basis of this achievement, the Government of the Philippines made an ambitious plan, with a goal of 3 million ha of hybrid rice planted by 2007. The above facts clearly indicate that hybrid rice technology developed by China is also effective in greatly increasing rice yield worldwide.

The ever-forwarding technology improvement by scientists and its dissemination by seed industries and extension workers, as well as policy and financial support by national and local governments, contribute greatly to the successful development and use of hybrid rice technology. It is my firm belief that hybrid rice, relying on scientific and technological advances and the efforts, in particular, of FAO and IRRI, has very good prospects for commercial production and it will continue to play a key role in ensuring food security worldwide in the twenty-first century.

Finally, as Director General of the China National Hybrid Rice Research and Development Center, I am pleased to announce that we will try our best to help other countries to speed up the development of hybrid rice throughout the world.