| In this study,19 Diospyros kaki Thunb.‘Jiro' orchards in Longyang district Baoshan Yunnan Province were used as materials,through the investigation of management status,growth traits,fruit yield and quality,growth dynamics and measurement of mineral elements of soil,leaf and fruit.The differences of growth traits,fruit yield and quality of orchards under different management levels were analyzed.The relationship between mineral elements of soil,fruit,leaf and fruit quality was analyzed with a variety of statistical analysis,and the dynamic variation rule of main mineral elements in leaves and fruits were studied.The appropriate ranges of main mineral elements needed for good quality and high yield orchards were studied.The research shows:1.Through the investigation of the management status and growth traits,fruit yield and quality of 19 Diospyros kaki Thunb.‘Jiro' orchards,the 19 orchards were divided into three categories by the evaluation analysis and systematic clustering analysis.The results showed that fruit quantity,single fruit weight,single yield have highly significant difference among 3management levels?P<0.01?,There is significant difference between 1 and 3 level about fruit firmness.Soluble solid and vitamin C reach the extremely obvious difference between 1 level and 2,3 level.The content of carotenoid in 1,2 level is higher than 3 level significently.At the same time,most branches traits and leaf traits also reach significent difference.2.The observation of phenological period and dynamic observation indicated that During the growth and development period of fruit,there were two growth peaks in 7-9 weeks?the first time?and 15-17 weeks?the second time?after full blooming.The rate of fruit growth showed “fast-slow-fast” trend.The dynamic changes of N,P,K,Fe,Zn and Cu in leaves and fruits were similar between different locations and varieties of sweet persimmon,but there were obvious difference of Ca,Mg and Mn in Yunnan and Zhejiang Province.The contents of N,P,K in leaves were lower in comparison and in the process of rapid decline during sprout leaves period to pre-flowering.P fertilizer should be be applied with basal fertilizer because ofits poor liquidity.The N,K fertilizer should be added during sprout leaves period and should give priority to N fertilizer to promote vegetative growth.During two fruit inflating stages,the contents of N,P,K in fruits decreased continually,top application is necessary and should give priority to K fertilizer to improve fruit quality before two fruit inflating stages coming.(7-9weeks and 15-17 weeks after full blooming.)The optimum period for leaf sampling of sweet persimmon is 9-10 weeks after full blooming.3.Comparing measured values with theoretical values of soil and leaf nutrient content,the result showed that soil organic matter content is all lower than theoretical values.There are lower soil available P and Fe content in 47.37% orchards and higher leaf N content in 84.21%orchards,at the same time,there are lower leaf P,K,Mn content in 15.79%,26.32% and84.21% orchards.Under the optimum proposals for soil and leaf respectively,the fruit mass could reach 331.42 g,328.63 g,along with firmness 18.463 kg·cm-2,17.118 kg·cm-2,soluble solids 18.664%,18.056%,vitamin C 165.22 mg·100g-1,141.012 mg·kg-1,carotenoid 66.70mg·kg-1,71.36 mg·100g-1 in theory.The results indicate that there are sufficient soil nutrient content but insufficient leaf nutrient content in ‘Jiro' orchards.Organic matter and P,K fertilizer should be increased,decreasing N fertilizer should be decreased properly.It is a key point to regulate the percentage of soil nutrients and balance the nutrition of the tree body in‘Jiro' orchards in Longyang District,Baoshan City.4.The content of fruit mineral elements in different orchards varied greatly,and the order of the average content of fruit mineral elements was: K> N> P> Ca> Mg> Fe> Mn> Zn> Cu.The correlation between fruit mineral elements was better than leaf mineral elements.By path analysis,N?-0.42?,Ca?-0.38?,Cu,?0.332?had significent direct affect to fruit weight,Ca?0.3630?,Cu?-0.3150?,Zn?0.2660?had significent direct affect to fruit firmness,soluble solid was affected by Ca?-0.6670?,N?-0.3670?directly.Fruit P?-0.495?,Ca?0.428?,K?0.394?had significent direct affect to vitamin C.The order of the direct affect to carotenoid was: K?-0.7770?> N?0.4520?> P?0.4210?> Mn?0.3920?> Ca?-0.3840?.5.The principal component analysis and comprehensive evaluation showed that yield and fruit weight of the orchards are the most important indicator in the whole comprehensiveevaluation system.The variation coefficients of N,P and K in ordinary orchards were larger,The suitable range of N,P and K determined by high quality and high yield orchards as: N20.80—27.84 kg/mu,P 6.94—8.06 kg/mu,K 16.83—26.19 kg/mu,the ratio of N,P and K is roughly 10: 3: 8.While Fertilization is not currently scientific and balanced in Baoshan Sweet Persimmon orchards.Through the research,we mastered the changes rule of mineral element contents The key period of fertilizer and appropriate sampling stage of sweet persimmon were determined.The theoretical support for fertilization and nutrient diagnosis of sweet persimmon orchards was provided.We drew a conclusion that fertilization is unbalance in part of orchards.The suitable range of N,P and K determined by high quality and high yield orchards was found,the theoretical support for fertilization and nutrient diagnosis of sweet persimmon orchards was provided. |
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