红麻是短日照作物,从日照时数较短的南方引种,到日照时数较长的北方种植,营养生长期延长,麻株长的高大,纤维增产显著。但是生殖发育推迟,收不到成熟种子,需要年年从广东、广西调种,而且调种量逐年增加,南方不能满足北方种植红麻的用种。为了解决这个矛盾,我们依据植物光周期理论, Kenaf is a short-day crop, introduced from the south with short sunshine hours to the northern planting with a longer sunshine duration. The vegetative growth period is prolonged. The hemp grows tall and the fiber yield increases significantly. However, postponement of reproductive development, the harvest of mature seeds can not be achieved, and it needs to be planted annually from Guangdong and Guangxi. Moreover, the amount of seeds to be planted increases year by year, and the south can not meet the need for planting kenaf in the north. In order to solve this contradiction, we based on the theory of plant photoperiod,