The yield of tuber and colchicine content could be increased by means of promoting the growth of stem and leaves and elongating the effective photosynthetic time before the peak appeared.
The stress is very complex and may reach to a peak value exceeding the yield stress of the material.
其应力分布非常复杂，而且有超过材料屈服应力的应力峰值。
3
The grain yield in China has been reduced after 1998, the year when grain production reached the peak level in the history, and it turned into the lowest level in 2003.