Abstract: The effects of nitrogen, phosphorus and potassium fertilizers and combined application on the growth of flue-cured tobacco seedlings were studied and the fertilization technology of flue-cured tobacco seedlings was optimized in this paper. Using floating seedlings of the new flue-cured tobacco cultivar Guiyan 202 as the test material, the effects of different fertilization treatments on the growth of flue-cured tobacco seedlings were studied by N, P2O5, K2O single-factor random block test and three-factor five-level quadratic regression almost orthogonal rotation combination test. The results showed that N, P2O5, K2O and their combined application treatments had significant effects on the growth indexes of flue-cured tobacco seedlings. However, the concentrations of P2O5 and K2O had no significant effects on the number of leaves; the higher N concentration, the more significant the effect on the leaf area of tobacco seedlings. The higher N concentration, the larger leaf area in the early stage of tobacco seedlings. While the concentrations of P2O5 and K2O had little effect on the leaf area, and with the growth of tobacco seedlings, the leaf area and the concentrations of P2O5 and K2O first increased and then decreased; Compared with the concentration of N, P2O5 and K2O, it first increased and then decreased. The reasonable ratios of N, P2O5 and K2O could improve the leaf number, stem diameter, seedling height and leaf area of flue-cured tobacco seedlings, and promote the growth of flue-cured tobacco seedlings. From the above growth indexes, the combination treatment of high nitrogen and medium phosphorus and potassium had the best effect in this experiment, when the concentrations of N, P2O5 and K2O in the nutrient solution were 10.50–12.00 mmol·L–1, 4.50–5.25 mmol·L–1 and 10.50 mmol·L–1, respectively.

Key words: flue-cured tobacco, nitrogen, phosphorus, potassium, growth characteristics

摘要： 以烤烟(Nicotiana tabacum)新品种贵烟202为试材，漂浮育苗，采用N、P2O5、K2O单因素随机区组试验及三因素五水平二次回归几乎正交旋转组合试验，研究不同施肥处理对烤烟苗期生长发育特性(叶片数、茎粗、苗高、叶面积等)的影响。结果表明，N、P2O5和K2O及其配施处理对烤烟苗期的生长指标影响显著，随着烟苗生长，营养液中N浓度越高对烟苗叶片数发育的影响逐渐增加，但是P2O5和K2O浓度对叶片数影响不显著；N浓度越高对烟苗叶面积影响越显著，烟苗早期N浓度越高叶面积越大，随着烟苗生长，叶面积随N浓度升高呈先增加后下降的变化趋势，在烟苗前期P2O5和K2O浓度对叶面积影响不大，随着烟苗生长叶面积随P2O5和K2O浓度升高呈先增加后下降的变化趋势；烟苗茎围亦随N、P2O5和K2O浓度升高呈先增加后下降的变化趋势。合理的氮磷钾配比施肥可提高烤烟幼苗的叶片数、苗高、茎围和最大叶面积，促进烤烟幼苗生长。从上述生长指标综合来看，高浓度N和中等浓度P2O5、K2O组合处理对烤烟苗促生长效果最好，即营养液的N、P2O5、K2O浓度分别为10.50～12.00 mmol·L–1、4.50～5.25 mmol·L–1和 10.50 mmol·L–1较适宜于烤烟苗期培养。

关键词: 烤烟, 氮, 磷, 钾, 生长特性