氮肥与多效唑促控结合对马铃薯生理特性及产量的影响

Effects of N Fertilizer Promoting and Paclobutrazol Controlling Combination on Physiological Characteristics and Yield of Potato

在大田条件下,采用裂区试验研究不同施氮水平下多效唑对马铃薯叶绿素含量、叶片光合参数、叶面积指数(LAI)、群体光合速率(CPR)、群体呼吸速率(CRR)以及马铃薯产量的影响。结果表明:增施氮肥可提高叶绿素含量,增强单叶的光合能力,同时降低呼吸消耗,但是随着LAI的提高,CRR增强,造成CPR下降;喷施多效唑减弱地上部的营养生长,提高叶绿素含量,降低LAI,低浓度多效唑促进光合,高浓度多效唑对光合有抑制作用;增施氮肥与喷施多效唑相结合,在保证合理LAI的情况下,CRR下降,CPR上升;从两年的试验结果来看,低氮处理(225 kg·hm-2)同时喷施100 mg·L-1多效唑产量最高,而高氮处理(295 kg·hm-2)并喷施300 mg·L-1多效唑产量最高。

Under the field conditions, the effects of different N fertilizer treatment combined with different concentrations of paclobutrazol （MET） on the chlorophyll content, leaf photosynthetic parameters, leaf area index （LAI）, canopy photosynthetic rate （CPR）, canopy respiratory rate （CRR） and yield of potato by split plot test. The results showed that the chlorophyll content could be increased, the single leaf photosynthet- ic capacity could be enhanced, and the respiratory consumption could be reduced by increasing application of N fertilizer. But along with the LAI increasing, the CRR enhanced, which resulted in the decrease of CPR. Spraying MET could reduce the aboveground growth, increase the chlorophyll content, and decrease the LAI. The photosynthesis could be promoted by low concentration of MET but inhibited by high concentration. Under the condition of ensuring reasonable LAI, higher N fertilizer combined with reasonable MET control decreased CRR and increased CPR. From the results of two years experiment, the yield was highest with the treatments of lower N （225 kg-hm^-2） combined with 100 mg·L^-1 MET and higher N （295 kg·hm^-2） with 300 mg-L^-1 MET.