前言试验所用牧草是从世界各地收集来的。热带牧草各原产地间的气候条件差异很大。有些牧草在严重干早到来之前,有些在严寒季节来临之前必须完成其种子成熟,而另一些由于全年生长在季节不明显的高温多雨气候条件下,繁殖与季节的关系可能不大。很多牧草的生殖生长始于对光周期环境的反应。因此,我们能够预期得出热带牧草的不 Forests used in the experiment are collected from all over the world. Climatic conditions vary considerably between tropical forages. Some forages have to mature their seeds before the onset of severe winter, and some may not have much to do with the seasons due to the year-round growth in a seasonally hot, rainy climates, before severe drought begins. The reproductive growth of many forages begins with the response to the photoperiodic environment. Therefore, we can expect to find no tropical pasture