| Phoebe bournei is an evergreen tree in Lauraceae Phoebe,and as a second-class protected plant,which has high ornamental value,economic value and cultural value.Because of its good adaptability and strong resistance,it has been listed in the national inventory of forest species,which is the preferred timber tree species for mountain afforestation,and has been more and more widely used in urban greening and landscape.Therefore,in recent years P.bournei seedlings in short supply.At present,the effect of the foliar fertilization on rice,apple,grape,cotton and other crops is remarkable,the foliar fertilization has gradually become an important fertilization measure in modern agriculture.However,the study on the foliar fertilization of P.bournei was not reported.Therefore,in this experiment,the 2-year-old P.bournei seedlings were used as experimental materials,using NPK and concentration four-factor three-level orthogonal design to studied the effects of NPK and concentration foliar fertilization on the growth and physiological and biochemical characteristics of 2-year-old P.bournei seedlings.The study provided the technical and theoretical basis for the development of foliar fertilizer,better and faster to provide a well-developed root system with strong quality of P.bournei seedlings.The main findings are as follows:1?Compared with the water CK group,the foliar fertilization treatments promoted the height growth of P.bournei,the ground diameter,fresh-weight,dry-weight,leaf area,root length and lateral-root quantity.The best effect was the treatment group S3(N1P3K3concen trat i on3,U rea34.78 3g,sodi um dihydrogenphosphate 15.210g,potassium sulfate 7.405g,spraying concentration 5%).The foliar fertilization treatments didn't change the regular pattern because all treatments growth spurts occur in June and September.N has greatest effect on height growth,K has the greatest effect on ground diameter growth,biomass,leaf area and lateral-root quantity,P has the greatest effect on root length.2?Spraying foliar fertilizer significantly increased net photosynthetic rate,stomatal conductance,transpiration rate,water and light use efficiency,and chlorophyll content of P.bournei,and decreased inter-cellular CO2 concentration.The characteristic parameters of Pn-Par curves and CO2-Pn curves at the different foliar fertilizers of Pnmax?AQY?LSP?CE?CSP were all higher than those of CK,LCP and CCP were decreased.The best effect was the treatment group S4 on Pn and LUE,S3 has the best GS?Tr,and chlorophyll content a+b.S2 was the lowest inter-cellular CO2 concentration and has the best WUE.K has the greatest effect on Gs?Tr and chlorophyll b content,N has the greatest effect on the other.3?Foliar fertilizer significantly increased the enzyme activity of leaves,promoted the increase of Pro content,reduced MAD content.The treatment group S1 has lowest MAD content and S7 has highest Pro content.The best effect was the treatment group S3 on improved the activity of SOD and CAT,S1 improved the activity of POD has best effect.P has the greatest effect on the MAD and Pro content and the activity of POD,N has the greatest effect on the activity of SOD and CAT.K had no significant effect on MAD content and CAT activity.4?Correlation analysis indicates:the correlation between the growth indexes,the photosynthetic indexes and the physiological indexes of P.bournei seedlings was a strong relatively,and there were some significant or extremely significant correlations among the growth,photosynthesis and physiological indexes,but not as significant as the correlation between the indicators.5?The results of principal component analysis and subordinate function modulus and comprehensive analysis showed that the comprehensive scores of S3(N1P3K3concentration 3)were the highest,which had the best effect on the seedling growth,and was the most suitable combination of foliar fertilizer of N,P,K and concentration to promote the growth of 2-year-old P.bournei seedlings. |
PDF Full Text Request