Study On Photosynthetic Characteristics,Yield And Quality Of Two Early Walnut Cultivars Under Three Planting Densities Difference In The Region Of Longnan

The experimental materials of this study were the two early fruiting walnu t cultivars??Qiangtele?and?Xiangling??,and the planting density respectively is3m×3m,3m×6m,6m×6m.Mainly analyzes in different planting densities of the walnut garden the dynamic change rule and discrepancy of photosynthetically a ctive radiation,temperature,humidity and air CO₂ concentration.To explore the effects of these environmental factors on photosynthetic characteristics,chloroph yll fluorescence characteristics,yield and fruit quality of walnuts.The purpose is to determine the suitable planting density of the two walnuts in actual produ ction.The results prove that:1.Differences in environmental factors in walnut garden under different pl anting densities.photosynthetically active radiation and temperatureare:6m×6m>3m×6m>3m×3m,humidity:3m×3m>3m×6m>6m×6m,air CO₂ concentration had little difference between different planting densities.There are large season dif ferences of these environmental factors,from April to August,Photosyntheticall y active radiation and humidity showed a single peak curve,the peak appeared in July;temperature rises rapidly from April to July,and smooth changes fro m July to August;Changes in air CO₂ concentrations have slightly decreased f rom April to August.2.Pn of two walnuts had difference in different planting densities,among,The Pn and Gs values of‘Qiangtele'walnuts were the highest at the planting density of 3m×6m,which were 7.39umol·m^-2·s^-11 and 0.02mol·m^-2·s^-1,respectiv ely.Tr was the highest at the density of 6m×6m,which was 3.08 mmol·m^-2·s^-1,and there was no significant difference among the three densities.The Pn and Gs values of'Xiangling'walnut were the highest at the planting density of 6m×6m,which were 7.15umol·m^-2·s^-11 and 0.11mol·m^-2·s^-1,respectively,and signif icant difference between the three densities.Tr was 3.58 mmol·m^-2·s^-11 reaches a maximum of at the density of 3m×6m,which is extremely different from the density of 3m×3m.There was no significant difference in Ci between the two types of walnuts,and the decrease of Pn was caused by non-stomatal limitati on at noon.3.Differences in Photoresponse Characteristic Parameters of walnut under Different Planting Densities;The LSP,LCP and P_maxax of two walnuts were sign ificantly higher than the density of 3m×3m at the planting density of 6m×6m.The performance of AQY was just the opposite.This shows that the two walnut s are more suitable for sparse planting in practical production.4.Differences in fluorescence parameters of two walnut varieties under dif ferent planting densities.‘Qiangtele'walnut Fm:3m×6m>6m×6m>3m×3m,Fv/Fo and Fv/Fm:3m×6m>3m×3m>6m×6m,Fo and qN:6m×6m>3m×6m>3m×3m;‘Xiangling'walnut Fo:3m×6m>3m×3m>6m×6m,Fv/Fo:6m×6m>3m×6m>3m×3m,Fm?Fv/Fm and qN:6m×6m>3m×3m>3m×6m;The daily average values of Fm,Fo/Fm,Fv/Fm and Fo,qN of‘Qiangtele'walnut were the highest under the planting densities of 3m×6m and 6m×6m,respectively.For‘Xianglin'walnut except Fo,the fluorescence parameters such as Fm,Fv/Fo,Fv/Fm and qN all appeared in the highest daily average values under the planting density of 6m×6m.It can be considered that‘Qiangtele'and‘Xiangling'walnuts have better photosynthetic efficiency under the planting density of 3m×6m and 6m×6m,re spectively.5.Planting density has a greater impact on walnut yield and quality,The single fruit weight and the yield per plant of‘Qiangtele'and‘Xiangling'walnu ts reached the maximum at the planting density of 6m×6m,which was signific antly greater than 3m×3m,Among them,the average yield per hectare of‘Qia ngtele'walnut reached the highest under the planting density of 3m×6m,which was 37577.78kg/hm².The average hectare yield of‘Xiangling'walnut reached t he highest at the planting density of 3m×3m,which was 14044.44kg/hm².At t he same time,with the planting density of 6m×6m,the average hectare yield was also reached 12066.67kg/hm².The SS,SP and CF of two walnut fruit quali ty contents were significantly higher than the density of 3m×3m at the densit y of 6m×6m,and they showed a decreasing trend with the increase of planting density.Based on the above results,3m×6m and 6m×6m are the appropriate planti ng densities for‘Qiangtele'and‘Xiangling'walnuts respectively,which can ach ieve unity of yield and quality,indicating that this configuration can make full use of site resources and maximize Economic benefits,it have a certain prom otion value in practical production.