棉花是我省主要经济作物,适时种好棉花,提高棉花的产量和品质,对于促进四化建设,增加农民收入,具有十分重要的意义。生产实践证明,棉花苗全、苗齐、苗壮是高产的基础,确定适宜的播种日期,是争取一播全苗的关键。关中棉区属大陆性暖温带季风气候,历年四月正是冬夏过渡季节,气候变化较大,温变很不稳定,致使棉花的适宜播期很难掌握。播种过早或播后遇到阴雨,由于地温回 Cotton is the main cash crop in our province. It is of great significance to plant cotton in good time and to increase the yield and quality of cotton for promoting the four modernizations and increasing farmers’ income. Production practice has proved that the whole cotton seedlings, Miao Qi, Miao Zhuang is the basis for high yield, to determine the appropriate planting date, is the key to a broadcast of seedlings. The Guanzhong cotton area belongs to the continental monsoon climate of continental nature. In April of last year, it is the transitional period of winter and summer. The climate change is rather large and the temperature changes are unstable. As a result, the suitable sowing date of cotton is hard to grasp. Sowing too early or rainy after sowing, due to geothermal back