喷施硅肥对烤烟圆顶期光合特性、氮钾含量及产质量的影响

摘要

为了探讨喷施硅肥对烤烟生长发育的作用效果,在陕南旬阳县以品种K326为材料开展了喷施硅肥试验研究.结果表明:在团棵期和现蕾期或团棵期和打顶后2d喷施浓度为1.5 kg/hm2或3 kg/hm2的硅肥,均能不同程度提高烤烟圆顶期净光合速率、水分利用效率和气孔导度,同时降低蒸腾速率,增加叶绿素含量,提高烟叶氮钾含量,进而提升均价、产量、产值及中上等烟比例.在相同的喷施浓度下,团棵期和打顶后2d喷施硅肥作用效果优于团棵期和现蕾期喷施;在相同喷施时期下,喷施浓度3 kg,/hm2作用效果优于喷施浓度1.5 kg/hm2.其中,以团棵期和打顶后2d喷施硅肥浓度为3 kg/hm2 (D2)处理效果最好,能有效提升烤烟光合作用,改善氮钾营养,促进烤烟生长发育,提高经济效益,从而为陕南烟区硅肥施用提供参考.%A field experiment was conducted by spraying silicon fertilizer to elucidate the improving effect on growth and development of flue-cured tobacco using K326 as material in Xunyang county of southern Shaanxi province.The chlorophyll content,the net photosynthetic rate (Pn) and stomatal conductance (Gs),nitrogen and potassium contents increased,while transpiration rate (Tr) decreased at topping stage regardless of the spraying time or concentration under silicon fertilizer treat condition.Spraying silicon fertilizer improved the average price,yields,output values and proportion of superior tobacco.Application of silicon fertilizer at rosette stage and two days after topping showed better effect than that at rosette stage and budding stage when supplying with the certain concentration of silicon fertilizer.Moreover,the effect of 3 kg/hm2 silicon fertilizer treatment was better than that of 1.5 kg/hm2 treatment at the same treatment time.The D2 treatment i.e.spraying 3 kg/hm2 silicon fertilizer at rosette stage and two days after topping,had efficiently improved the photosynthesis,nitrogen and potassium nutrition,promoted tobacco growth and increased economic efficiency.In conclusion,exogenous application of silicon fertilizer could provide a theoretical basis for promoting growth of tobacco in production of the southern Shaanxi province.