北方稻区的粳稻品种都具有很强的感温性,中早熟品种的感温性更为明显。同一品种在同一区域用同一栽培方式种植,其生育日数、叶片数量和经济产量是相对稳定的。而同一品种在不同区域种植或在同一区域采用不同播期方式栽培种植,其生育日数会出现长与短的变化,叶片数量可出现多与少的变化,经济产量也表现出 Rice varieties in the northern rice region have a strong sense of temperature, medium-early-maturing varieties of temperature is more obvious. The same variety in the same area in the same cultivation methods of planting, the number of days of its birth, the number of leaves and economic output is relatively stable. The same variety in different regions planted or in the same area using different sowing methods of cultivation, the number of days of birth will have long and short changes in the number of leaves may appear more and less changes in economic output also showed