郑单二号是当前种植面积较大的优良单交种。为了探索夏玉米高产栽培的理论依据,我们于1979年在高肥水条件下,对郑单二号的生育规律进行了系统的观察研究。一、试验研究方法本试验在我校试验田进行。6月7日播种,密度4286株/亩,9月12日成熟。亩收4209穗,每穗361.9粒,千粒重340.7克,实 Zheng Dan II is the current planting area of ​​the fine single cross-species. In order to explore the theoretical basis of high-yielding cultivation of summer maize, we conducted a systematic observation on the fertility rule of Zheng Dan-2 in high fertility conditions in 1979. First, the experimental research methods The test in our school experimental field. June 7 planting, density 4286 plants / mu, September 12 mature. Mu harvest 4209 spike, 361.9 grains per spike, grain weight 340.7 grams, real