打顶后NAA处理对烟草生长、烟叶中钾和烟碱浓度的影响

在云南省田间连续三年研究了打顶后在茎断面涂抹萘乙酸(NAA)处理对烤烟植株生长、钾素吸收、烟叶中钾和烟碱浓度的影响。结果表明,打顶导致烟株中的钾素损失,烟叶中钾浓度下降,烟碱浓度增加。打顶后在茎断面用NAA处理可以增加烟株对钾素的吸收,促进钾素向叶片中分配,使叶片钾浓度提高;同时降低叶片烟碱浓度。第一次NAA处理两周后用NAA再处理一次虽然可以进一步提高烟叶钾浓度,但使叶片干重稍有下降,且在操作上多一道工序。若开花后不打顶,虽然叶片中钾浓度较高,但大大降低了叶片干物重,严重影响叶片的产量和品质。

Effects of NAA application after removing the shoot apex on growth, K+ and nicotine concentrations in component tissues of flue-cured tobacco plants

Field experiments were conducted in three years(1999,2000 and 2001)in Yunnan province to study the effects of NAA application after removing the shoot apex on plant growth,K and nicotine concentrations in different organs of flue-cured tobacco.The results showed that,excision of the shoot apex caused a net decrease in total K content of whole plant,a decrease in K concentration while an increase in nicotine concentration in different leaves.Application of NAA onto the cut-surface of the stem after removal of the shoot apex stimulated K uptake and distribution into the leaves,resulted in increase in K concentration and decrease in nicotine concentration in different leaves.Applying NAA twice(once again two weeks after the first application)could further improve leaf K concentration,but cause a slight decrease in leaf dry weights.Keeping plant intact(no removing the shoot apex)resulted lower leaf dry weights and yield,and poor leaf quality,compared with the apex-removed plants,although the leaf K concentration was higher in the intact plants.NAA application one time after removal of the shoot apex was enough for increasing in K concentration and decreasing in nicotine concentration in tobacco leaves.