不同镁肥水平对烤烟光响应曲线及产量的影响

Effects of Different Magnesium Fertilizer Levels on Light-response Curves and Yield of Flue-cured Tobacco

为探究不同镁肥水平对烤烟光响应曲线及产量的影响,以烤烟K326为研究对象,采用直角双曲线模型、非直角双曲线模型和双曲线修正模型对烟株成熟期中部叶的光响应曲线进行拟合,通过分析光合参数的拟合值和实测值的近似度,选出光响应曲线适宜的拟合模型,在此基础上对比分析不同镁肥水平下烤烟的光响应曲线以及产量的差异。结果表明:双曲线修正模型能较好地拟合成熟期烤烟的光响应曲线。随着镁肥适量的增施,光合特征参数有所上升,烤烟叶片的光合能力有明显的提高,但当镁肥过量时光合特征参数反而下降。因此,本试验条件下,双曲线修正模型是拟合不同镁肥水平下烤烟光响应曲线的适宜模型,施镁量为150 kg/hm^2的处理能较为显著的提高烤烟的光合速率和产量。

In order to study the effects of different magnesium fertilizer levels on light-response curves and yield of flue-cured tobacco, the light response curve of central leaves of tobacco plants in maturity period were studied by using the flue-cured tobacco K326 as the research object. And three light re- sponse curve, including rectangle hyperbola model, non-rectangle hyperbola model and hyperbolic cor- rection model, were used to be screened out the optimal model via analyzing degree of approximation in fitted value and measured value, and on the basis of the comparison and analysis the light response curves and the yield difference of flue-cured tobacco under different levels of magnesium fertilizer. The main results showed that hyperbolic correction model can better fitting of flue-cured tobacco in mature light response curves. With the increasing of magnesium fertilizer right amount, photosynthetic charac-teristic parameters are increased, and the leaf photosynthetic capacity significantly improved, but when magnesium fertilizer excessive time characteristic parameters instead of down. Under different magnesi- um fertilizer levels, the rectangle hyperbola model was the best light-response curve models. The treat- ment that rate of fertilizer application of Mg is 150 kg/hm^2 can significantly improve the photosynthetic rate and yield of flue-cured tobacco.