生长后期不同断根及追钾对云南烤烟含钾量的影响

Effcts of different cutting-roots and K top-dressing measures at later growth stage on K-oncentration in leaves of fluecured tobacco plants in Yunnan Province

摘要: 田间试验研究生长后期不同断根及追钾对云南烤烟含K量的影响结果表明，不同断根时间、断根部位和断根数量以及断根时追K与否及追施K 素的形态等均对烤烟烟叶含K量的影响不同，烟株生长后期实施断根和追施K肥等措施可提高根系吸收活力和增加烟叶含K量。其中打顶时断根同时追施速效钾肥为最佳处理，其烟株各部位叶片含K量和上部叶片干物质量增幅最高，且易于实际操作。

Abstract: The effects of different cutting-roots and K top-dressing measures at later growth stage on K concentration in 1eaves of flue-cured tobacco plants were studied The results demonstrate that cutting-root and increasing application of K can stimulate the formation of new roots and then their uptake activity Cxmsidering both the K content and the leaf dry weight，the best measure is cutting-roots on the position 20 cm away from the stem base and simultaneously the top-dre-ssing with K₂SO₄ when plants are decapitated．