Study On Leaf Water Potential Change Rule Of Matured Walnut And Its Influencing Factors Of Research

This paper through field eexperient, in domestic and abroad fruit trees drip irrigation research status quo and existing problems on the basis of analysis, walnut tree which is 10 years as the research object, on 2010 April～2010 August, in the farm of grain and oil in Wensu county, Aqsu region, Study on Leaf Water Potential change rule of Walnut and its influencing factors under Drip Irrigation Condition,analyzed Leaf Water Potential of Walnut (LWPW) with meteorological factor,physiological indexes,yield and quality ,such as the influencing factors relations under different irrigation quota treatments;The research fruits was as follows:(1) Different months the LWPW change rule are after first reduce increased, showed that the LWPW in morning and evening is higher,at noon minimum, Average diurnal change amplitude is -2.33bar-9.62bar;(2) Under experimental condition, the relationship of early morning LWPW (ΨL) and soil moisture content (SWC) was different in different growth period. There's positive correlation between them in Fruit swollen period,Hardcore period and anaphase of fat conversion period, but negative correlation in Prophase of fat conversion period. Overall,There's negative correlation between LWPW and SWC, Matured walnut trees root zone that soil water drop, the early morning LWPW also fall subsequently, thus produce enough water potential gradient ensure the water supply for tree; When the root zone enough moisture, tree of water supply is fairly well, at this time the early morning LWPW will remain at a higher. Comprehensive analysis thinks, analysis established a regression equation of them in different growth period expressed as:SWC=aΨL+b(a,b are experience parameters, Can reference Table 3-1)(3) Analyzed LWPW with Solar radiation,atmospheric temperature,atmospheric relative humidity , such as the influencing factors relations. Showed that there's negative correlation between LWPW and atmospheric temperature and solar radiation; positive correlation between LWPW and atmospheric relative humidity;Path analysis of them showed that atmospheric temperature is the key factor to LWPW diurnal change, followed by more important factor than atmospheric relative humidity and Solar radiation;Air relative humidity, solar radiation and atmospheric temperature coefficient of the direct sizes are less than through the factors have indirect size coefficient, shows that three of less influence than indirect effects directly. Atmospheric temperature through the air relative humidity and solar radiation got indirect size coefficient is bigger, explain air relative humidity and solar radiation is atmospheric temperature changes caused by the main factors, Solar radiation is the deciding factor. Established a regression equation between LWPW and meteorological factor under experimental condition as well.ΨL=-a+bRH-cR (a,b,c are experience parameters, Can reference equation 2)(4) Analyzed LWPW (ΨL) with net photosynthetic rate(Pn),transpiration rate(Tr),stomatal conductance(Gs),leaf temperature (Tl) daily change relations.Showed that there's negative correlation between LWPW and net photosynthetic rate(Pn),transpiration rate(Tr),stomatal conductance(Gs),leaf temperature(Tl); LWPW (ΨL) and transpiration rate,leaf temperature very significant negative correlation, with net photosynthetic rate,stomatal conductance significant negative correlation;Path analysis of them showed that stomatal conductance is the key factor to LWPW diurnal change, followed by more important factor than transpiration rate,leaf temperature and net photosynthetic rate;Transpiration rate and leaf temperature in LWPW for negative influence, net photosynthetic rate and stomatal conductance in LWPW for positive influence; Through the analysis, under irrigation quota treatments T2 condition, LWPW as dependent variable, net photosynthetic rate,transpiration rate,stomatal conductance,leaf temperature as independent variables, using the linear multivariate stepwise regression analysis a regression equation is established:ψL=a-bPn-cTr+dGs-eTl(a,b,c,d,e are experience parameters, Can reference equation 3)(5) Analyzed stem sap flow rate(F) and LWPW(ψL) daily change relations, there's negative correlation between stem sap flow rate and LWPW, Established a regression equation between stem sap flow rate and LWPW:ψL=a-bF(a,b, are experience parameters, Can reference equation 4)(6) Determine the volume of soil water content scope and Leaf Water Potential of Walnut scope before irrigation.