东北三省玉米生育热量指标与品种熟型分布研究

采用东北三省73个气象站1971～1995年4月上旬至10月下旬的旬平均气温与9～10月逐日最低气温以及玉米分期播种 资料，分析和验证了玉米各发育期的热量指标。种子萌发的生物学下限温度为8℃，萌发至出苗期需≥8℃·d有效积温约 100℃·d，出苗至抽雄所需的≥10℃有效积温与品种的叶片数(熟型)有关；抽雄至成熟期的热量指标以订正后的标准抽雄日至 成熟所需≥10℃活动积温来表示，成熟期用成熟度达到1的日期来表示。本研究以某一品种80％年份正常成熟的标准来确定该 品种的栽培界线。

Heat Index of Maize Growth and Development, and Distribufion of Variety Types

Using the data of mean decade temperature of the flint ten days of Apr. to the last ten days of Oct., daily minimum tem peratme of Sep to Oct. from 1971 to 1995,and the data of maize planting date, the heat index of maize in various growth stages is calculated. The lowest biological temperature of seed germination is about 8℃. The effective accumulated temperature of ≥ 8℃ from germination to emergence is about 100℃ · d. The effective accumulated temperature of ≥ 10℃ fiom emergence to heading is related to the leaves of maize. The index from heading to maturity is expressed by active accumulated temperature of ≥ 10℃ from the cor rected standard heading day to maturity. Maturity data is the day when maturity degree equals to 1.The north planting boundary of different varieties was determined according to the criterion of maturity in 80% of years.