赤霉素(GA3)喷施时期对烤烟上部叶生长及产质量的影响

[目的]明确赤霉素不同喷施时期对烤烟上部叶开片的影响,进一步完善烤烟上部叶田间调控关键技术。[方法]采用田间试验,以喷施清水为对照(CK),设打顶后0 d(打顶当天)、1、2、3、4、6、8、10 d,共8个喷施时期处理,分析上部叶农艺性状、经济性状及化学成分的变化。[结果]相比各喷施清水对照,烤烟打顶3 d内喷施赤霉素均可有效促进上部叶开片,烟株上部叶面积和叶重增幅随喷施时间后移先升后降,各叶位增幅均以打顶后2~3 d喷施赤霉素处理最大。打顶后2 d喷施赤霉素,上部1~6叶平均叶面积和叶重增幅分别为24.8%和24.4%,上等烟比例、上等烟产量、总产量和产值分别提高2.7%、11.49%、7.24%和11.27%;烟碱降幅和总钾增幅最大,化学成分最为协调。[结论]在打顶后2 d喷施赤霉素最有利于烤烟上部叶开片和产质量的提高。根据天气情况,打顶后3 d内合理喷施赤霉素可有效避免降雨的影响,这对烤烟上部叶的有效调控具有实际意义。

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

[Objective] To study the effects of spraying times of gibberellin(GA3) on the growth of tobacco upper leaves,and to further perfect the key regulation technology for tobacco upper leaves in field.[Method] Field test was carried out.A total of eight spraying treatments were de-signed,including clean water (CK),0,1,2,3,4,6,8 and 10 days after topping.The changes of agronomic characters,economic characters and chemical components of upper leaves were analyzed.[Result] Compared with the controls,spraying GA3from 0 to 3 d after topping could effec-tively promote the leaf expansion of tobacco upper leaves.Leaf area and leaf weight firstly enhanced and then reduced as the spraying time pro-longed.The increasing rate of each leaves reached the maximum at 2-3 d after topping.Spraying GA3on 2 d after topping,the increasing rates of average leaf area and leaf weight of upper 1-6 leaves were 24.8% and 24.4%,respectively.And the proportion and yield of first-class tobacco, the total yield and the output value enhanced by 2.7%,11.49%,7.24% and 11.27%,respectively;the decreasing rate of nicotine and the in-creasing rate of total potassium were the maximum,and the chemical components were the most coordinate.[Conclusion] Spraying GA3on 2 d af-ter topping was the most beneficial to promote the expansion,yield,and quality of tobacco upper leaves.Based on the weather conditions,spraying GA3from 0 to 3 d after topping could effectively avoid the influence of rainfall,which was of practical significance to effective regulating the to-bacco upper leaves.