湘西武陵山区单季稻生长发育及物质生产的研究 Ⅰ 播期对杂交稻生长发育的影响

A Study on Growth and Dry Matter Production of Rice in Wuling Mountain Area Ⅰ.Effects of Sowing Dates on Growth and Development of Rice

各海拔试验点不同播期水稻插秧后,随播期推迟,前、中期株高的增长速度加快;出叶速度也有加快的趋势,但主茎总叶数逐渐减少;水稻分蘖速度加快,有效分蘖数增多。从生育进程看,播期推后使幼穗分化始期和抽穗期渐次推后;同一海拔高度,全生育期的天数和≥10℃活动积温随播期后移而减少。在生殖生长期内,长穗期日数和活动积温随播期推后而增加,结实期日数和活动积温随播期推迟而减少。综合分析认为,低、中海拔以4月上旬、高海拔以4月中旬播种较合适。

In the three different elevation sites,with the sowing date postponing,the plant height in- creased faster at early stage;and the leave emerged faster,but the total leave number was slightly de- creased;tiller emerged faster and bearing tillers number increased also.As to rice growth and develop- mant process,with the postponing of sowing date,date of young panicle differentiation and date of heading was delayed.In the same elevation,the days and ≥10℃ accumulative temperature of the whole stage was decreased with the sowing date postponing.The reason mainly was the period of vegetative growth short- ening,and the generative growth phase was steady relatively.In the generative growth phase,the days and≥10℃ accumulative temperature in the ear bearing stage increased along with postponing of sowing date,and those in productive stage reduced,This result was very obvious in the low altitude site.Accord- ing to analyzing,in the low and middle altitude area date which is suitable to rice sowing was the period of the first ten days in April,while in high altitude area was the period of the second ten days in April.