分次施钾模式下雪茄烟根系发育、干物质累积及根组织结构动态变化

Dynamic changes in root development,dry matter accumulation and root anatomical structure of cigar tobacco under split potassium application pattern

研究分次施钾对雪茄烟根系和根组织细胞生长发育、干物质累积及烟叶经济性状的影响,为本地雪茄烟生产确定适宜的施钾模式。试验设置3种施钾模式:CK(分1次施钾)、T1(分2次施钾)、T2(分3次施钾),分析不同时期烟株根系发育、干物质累积、根组织结构动态变化及发酵分级后雪茄烟叶经济性状。结果表明,各处理烟株根系活力随生育期进行均呈先升后降的趋势,干物质累积量逐渐上升,且分2、3次施钾较分1次施钾提高了烟株生育期的根系活力及中后期干物质累积量;40 d时分2、3次施钾处理根体积、根横切面积、中柱面积及导管数量较小,但分2次施钾较分1次施钾根冠比、根皮层厚度分别显著提高9.22%、38.57%;60 d后分2、3次施钾处理根体积及干物质累积量较分1次施钾显著提高,根冠比较小,80 d时T1、T2处理根横切面积、皮层厚度、中柱面积及导管数量显著高于分1次施钾,分2、3次施钾处理根、茎、叶干物质累积量较分1次施钾分别提高12.73%、14.73%、14.11%和15.78%、23.33%、17.55%。发酵分级后烟叶产值和茄衣比例均以分3次施钾处理最高,分别为6.70万元/hm^(2)和23.89%,其次为T1处理,分别为6.65万元/hm^(2)、22.88%。综上所述,分次施钾较1次施钾能够显著促进雪茄烟根系发育及干物质累积,优化根组织结构,提高烟叶经济效益,以分3次施钾效果最好,分2次施钾效果次之。

To study the effects of potassium application on the growth and development of root and root tissue cells,dry matter accumulation of cigar tobacco and economic properties of cigar leaves,and to determine the appropriate potassium application model for local cigar production.Three potassium application modes were set up in the experiment:CK(divided into 1 K application),T1(divided into 2 K application)and T2(divided into 3 K application).Dynamic changes of root development,dry matter accumulation,root tissue structure and economic properties of cigar tobacco after fermentation grading were analyzed at different periods.The results showed that the root activity of cigar tobacco in all treatments showed an increasing and then decreasing trend with the fertility period,and the dry matter accumulation was gradually increased,and the application of potassium in 2 and 3 times increased the root activity and dry matter accumulation in the middle and late stages of the fertility period of tobacco plants compared with the application of potassium in 1 time.Root volume,root transverse area,mid-column area and number of conduits were smaller in 2 and 3 applications of potassium at 40 d,but the root-crown ratio and root cortex thickness were significantly increased by 9.22%and 38.57%with 2 applications of potassium compared with 1 application of potassium.Root volume and dry matter accumulation were significantly higher in treatments with 2 and 3 potassium applications after 60 d compared with 1 application,and root crowns were smaller.At 80 d,the root transverse area,cortex thickness,mid-column area and the number of conduits were significantly higher in the T1 and T2 treatments than in the 1st application of potassium,and the dry matter accumulation of roots,stems,and leaves was increased by 12.73%,14.73%,14.11%,and 15.78%,23.33%,17.55%,respectively,in the 2nd and 3rd treatments compared with that in the 1st application of potassium.Both the value of tobacco production and the ratio of cigar wrapper after fermentation grading were highest in the treatment with potassium applied in 3 times as 67000 yuan/hm^(2) and 23.89%,followed by the T1 treatment as 66500 yuan/hm^(2) and 22.88%.In conclusion,divided application of potassium can significantly promote the root development and dry matter accumulation of cigar tobacco,optimize the root tissue structure,and improve the economic benefits of tobacco compared with 1 application of potassium,and the best effect was achieved by 3 applications of potassium,followed by 2 applications of potassium.