夏直播早熟玉米的积温及其在生产中的应用

Accumulated Temperature of Early-maturing Summer Maize and Its Application to Production

研究了鲁原单4号早熟玉米夏播的叶片数、积温、生育期和适宜追肥期。结果表明,叶片总数是相对稳定的,一般为17~18片,叶片伸展期平均所需天数8 d,积温220℃左右,全生育期83~85 d,需积温2100℃以上。最佳追肥期为叶指35.3,适宜追肥期为叶指17.6~52.9,土壤肥力高或施用基肥的取适宜范围的上限,土壤肥力低或长势弱的取其下限。

Early-maturing maize cv.Luyuandan 4 was sowed in summer to study the leaf number,accumulated temperature,growing period and appropriate top dressing period.The results showed that the leaf number,usually 17~18,was relatively stable.The leaf extending period was about 8 days and the accumulated temperature was about 220℃.The whole growth period was 83~85 days and the accumulated temperature was above 2 100℃.When the leaf area index was 35.3,it was the optimum period for top dressing.When the leaf area index was 17.6~52.9,it was the appropriate period for top dressing.When the soil fertility was high or the basal fertilizer was applied,it should take the upper limit.On the contrary,it should take the lower limit of the appropriate period.