海拔对我国北方旱农地区玉米生育天数的影响

Effect of Altitude Above Sea Level Upon the Number of Growing Days of Maize in Dryland Farming Area of North China

１９９２和１９９３年，在北方旱农地区的山西省寿阳县海拔１５００ｍ以下地区，开展了玉米垂直生态试验。年度气候条件正常，早熟和中早熟品种能完成生活周期。随着海拔升高，旱地玉米播种至成熟天数以及播种至拔节天数都逐渐增多，和海拔之间呈极显著正相关。播种至成熟天数也和播种至拔节天数呈极显著正相关。三段生长表现“长──短──长”的“两长一短”特征。株高与海拔之间呈极显著负相关。品种和栽培措施合理，在正常天气条件下，高地玉米也可获得高产。

Vertical ecological experiments on maize, Zea mays L.were carried out in1992 and 1993 1n Shouyang County with an altitude below 1500m above sea level ShanxiProvince in the dryland farming area of Norh China. Results indicated that the early ma-turing and medium- early maturing maize varieties could complete their growing cyclewith the normal yearly climatic condition.The days from sowing of maize to its maturityand that from sowing to elongation increased gradually with an increase in altitude sothat there appeared to have a significant positive correlation,and so was there a very sig-nificant positive correlation between the days from sowing to maturity and from sowingto elongation. The growth of three stages was characterized by ‘long- short- long’,i.e. two longs and one short.The significant negative correlation was also observed amongthe plant height and altitude. Under the normal climatic conditions,high yield of maizein hinh- altitude localities can be obtained provided the maize varieties and cultural prac-tices are rational.