摘要
本文采用数学模拟方法,研究了不同栽培密度对棉花干物质累积进程的影响。同一时期无论是全株还是营养器官或生殖器官干物质积累都呈现随密度增加而减少的趋势,而密度对群体干物质累积的影响与上述情况相反,即各时期干物质累积量,低密度的明显比中、高密度的低。密度对干物质累积的上述影响都随生育期的推延而增强,一般在开花期后才出现较明显的差异。根据干物质累积规律,把干物质累积速率曲线上二个"拐点"之间的区域称为干物质累积的"关键时期",其主要特征是在较短的时间内(一个月左右)能累积较多(占干物质总量的57.7%)的干物质。经计算,单株干物质累积的关键时期出现在7月中旬至8月中旬,这时黄淮海棉区的棉株生长正处于花铃期,这为加强花铃期的田间管理提供了一定的依据。
Aided with computer simulation,the process of cotton dry-matter accumulation and its response to the various densities are searched in the present paper.In a same period,the dry-matter weight of a plant or its organs decreased when the responsible density increased; while the colony dry-matter weight did the opposite:That is to say that the dry-matter weight was obviously lighter under low density than under medium or high density in each physiological stage.Further more,all those effects of density would become stronger if the cotton physiological stage came late.The effects were generally seen after bloom period.We call the time period between the two points that corresponded respectively to the two twists on the dry-matter accumulation velocity curve key period,In this period,dry-mater accumulation was 57.7% of the total,and much more than that of other periods.It can be inferred that the key period for a single plant is between the middle of July and August,This view is valuable to the cotton management in the stage.
关键词
棉花
密度
干物质
栽培
cotton
density
dry-matter accumulation
