不同氮素水平对烤烟生长发育的影响

研究了不同氮素水平下烤烟的大田生长发育规律。结果表明：除严重缺氮（未施氮）外，不同氮素水平对出叶速度和总出叶数没有影响；随着氮素水平提高，田间叶面积系数、烟株最大叶面积和地上部干物质量不断增加，氮素过量造成的烤烟过度生长主要是从旺长后期开始的；适宜氮素用量（本试验为６ｋｇ氮／亩）烤烟旺长前、旺长期和成熟期的干物质积累比例分别为１５％、６０％和２５％，经济系数约为７５％。

Effects of different nitrogen levels on the growth and development of flue-cured tobacco

The growth and development of field flue cured tobacco under different nitrogen levels were studied. The results indicated that different nitrogen levels had no effects on leaf emerging rate and total leaf emerging numbers except no nitrogen application; leaf area coefficient maximum leaf area and yield of dry matter in the above ground parts increased steadily as nitrogen levels increased, tobacco over growth due to nitrogen excess began mainly from later vigorous growth stage; dry matter accumulation ratios of tobacco were 15% 60% and 25% respectively in early vigorous growth stage vigorous growth stage and mature stage, economic coefficient was about 75% under the proper nitrogen level (6 kg N/mu ).