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国内外大量生产实践证明,推广应用优良玉米杂交种,是夺取玉米高产最有效而又经济的方法。我国从七十年代起,迅速推广了单交种,玉米的单产水平和总产都有大幅度提高。和美国相比,我国应用自交系间杂交种比美国晚26年;但从双交到单交的过渡比美国少16年.美国玉米单产从1939年的248斤提高到1959年的430.7斤,花了整整20年,玉米杂交种的增产效果为26.6～35.5%,而我国则用了10年,增产效果达41.9%,说明我国玉米生产发展速度是快的。但是美国1979年玉米单产已达917斤,而我国目前单产只相当于美国1959年的水平.玉米杂交种占玉米面(?)的比例约比美国低30%左右.可见,我国玉米生产还有很大的发展潜力.
Mass production at home and abroad have proved that the popularization and application of fine hybrid corn is the most effective and economical method to capture high yield of corn. Since the seventies, China has promptly promoted the single cross-breeding. The yield per unit of corn and the total output of maize have greatly increased. Compared with the United States, the application of hybrids between inbreds in China was 26 years later than that in the United States, but the transition from double cross to single cross was 16 years less than that in the United States. The yield of U.S. corn increased from 248 kg in 1939 to 430.7 kg in 1959 , Spent a full 20 years, corn hybrids yield 26.6 ~ 35.5%, while our country spent 10 years, yield increased by 41.9%, indicating that China’s corn production and development is fast. However, the yield of corn in the United States reached 917 kg in 1979, while the current yield in China is only equivalent to that of the United States in 1959. The percentage of maize hybrids to cornmeal (?) Is about 30% lower than that of the United States. Great potential for development.