The sub - model for design of population density was developed according to the principle of determining boll number from target yield , fruit node from boll number , fruit branch from fruit node and population density from fruit branch by integrating the effects of sowing date , cutout date , effective temperature accumulation above 12 , variety type , and fertilizer and water management levels . sowing rate was then decided by integrating the effects of different soil water and salt contents , ph , temperature and sowing style on seedling emergence rate with relative weight method 基于“以产定铃、以铃定节、以节定枝、以枝定苗”的原理，同时考虑播种日期、打顶日期、 12的有效积温、品种株型特性、肥水管理水平差异等因素来确定适宜的种植密度；在此基础上，应用相对权重法计算土壤含水量、含盐量以及整地质量和播种方式等多个生态环境因子对出苗率的综合影响，进而确定播种量。
2.
In planting ratoon sugarcane , " four early " : ploughing soil so as to loose sugarcane sprout , applying fertilizer during seedling so as to provide necessary nutrition for growing early and rapidly , early thinning out and singling seedling with shelling sear leaves so as to insure available populations and ventilation , controlling diseases and pests so as to ensure sugarcane seedling orderly , full and healthy 宿根蔗突出“四早”管理，即早破垄松蔸，促进蔗蔸萌发；早施苗肥，促进蔗苗早生快发，保证养分有效供给；早间苗、定苗，及时剥除枯脚叶，确保甘蔗有效群体和田间通透性；早防治病虫，保证苗齐、苗全、苗匀、苗壮。
