Altitude effects on maize growth period and quality traits

In order to optimize maize production and variety utilization in high altitude areas, the growth period and some quality traits of three maize varieties were compared among five elevations, 1280.0, 1506.5, 1706.5, and 2000.0, 2231.5 m in Gansu province and three elevations, 1435.0, 1860.0, and 2186.0 m in Yunnan province, China. This vertical ecological experiment was conducted in 2008 and 2009. The results showed that the growth period of maize sowed at similar time was extended along with altitude elevating, there was about 4-5 d extension with each 100 m increase in altitude. Both fat content and amylose/starch ratios had significant negative correlations with altitude, no correlation was found between crude protein content and altitude.