赤霉素(GA3)浓度对烤烟上部叶生长及产质量的影响

目的]明确不同赤霉素(GA_3)浓度对烤烟上部叶生长的影响。方法]针对山地和坝地烟田,采用一年多点的田间试验,研究了不同GA_3浓度对烤烟上部叶面积、干重、产量和化学成分的影响。结果]2类烤烟上部叶面积和干重增幅随GA_3浓度升高均先升后降,随叶位下移逐渐降低。山地以GA_3浓度20 mg/L效果最佳,上部平均叶面积和干重增幅近20%,新平和易门县产量分别增加5.2%和15.0%;坝地以30 mg/L最优,平均叶面积和干重增幅为25%~30%,新平和峨山县产量分别增加7.0%和11.9%。同时,2类烤烟上部叶烟碱含量下降,总钾含量普遍升高,化学成分趋向协调。结论]适宜的GA_3浓度可有效促进烤烟上部叶开片、增产和化学成分的协调,而低浓度作用较小,浓度过高会推迟烟叶成熟,影响烘烤质量。

The Effects of Gibberellin(GA3)Concentration on the Growth,Yield and Quality of Tobacco Upper Leaves

Objective]To research the effects of different concentrations of gibberellin(GA3)on the growth of upper leaves of flue-cured to-bacco.Method]Field test was carried in mountainous and dam land by one year multi-sites.Effects of different concentrations of gibberellin (GA3)on the upper leaves area,dry weight,yield and chemical components were studied.Result]The growth rate of both average leaf are-as and dry weight of tobacco upper six leaves were increased and then declined as the spraying concentration of GA3increased from 0 to 50 mg/L, meanwhile the growth rates declined with the drop of leaf position.For the mountainous tobacco, the spraying of 20 mg/L GA3in-creased the leaf area and dry weight of tobacco upper six leaves by 20%,which resulted in 5.21%and 14.97%yield increase of Xinping and Yimen Counties,respectively.For the dam tobacco,the spraying of 30 mg/L GA3increased leaf areas and dry weight by 25%-30%,which resulted in 7.00% and 11.91% yield increase of Xinping and Eshan Counties, respectively.At the same time, the two treatments could re-duce the contents of nicotine, increase the total potassium, and improve the coordination of chemical components of tobacco upper leaves in both the mountainous and dam land.Conclusion]The spraying of appropriate GA3concentration effectively promoted the expansion, in-creased the yield, and resulted in the coordination of chemical components in the tobacco upper leaves.Lower GA3concentrations showed no obvious effects, while the higher GA3concentrations delayed the mature of upper leaves and affected the baking quality of tobacco.