Effects Of Polypeptide Spraying On Yield And Quality Of Fresh Grape

[Object]Grape is one of the important characteristic fruit trees in Xinjiang.At present,the production often only focuses on the application of a large number of elements,while ignoring the supplement of medium and trace elements,which will lead to the decline of grape fruit quality.Polypeptide is a bioactive substance,which has the effect of promoting plant growth and improving crop quality.Polypeptide is also a good chelating agent.It can be applied with medium and trace elements to increase its effectiveness and promote the absorption of mineral nutrients by plants.Under the condition of calcareous soil,the effectiveness of magnesium,zinc and other elements is reduced due to the influence of high calcium magnesium ratio and high p H,and can not be fully absorbed and utilized by plants.The application of polypeptide may be a better solution,but the applicable concentration and effect of polypeptide spraying on grape leaves are not clear.Therefore,this experiment intends to explore the optimal application concentration of peptides by spraying peptides with different concentrations,so as to clarify the impact of peptides on grape yield and quality.Apply polypeptide and amino acid with Mg SO₄and Zn SO₄respectively,explore the effect of polypeptide and amino acid on grape mineral nutrient absorption while supplementing magnesium and zinc for grapes,and screen foliar fertilization treatment that can improve grape yield and quality,so as to provide a theoretical basis for the application of polypeptide in agricultural production.[Methods]In this study,Moritani seedless grape was used as the test material,which can be divided into three experiments.Experiment 1:The effects of different concentrations of polypeptide on grape yield and quality,a total of 5 different concentrations of polypeptide were set（0,0.05%,0.10%,0.15%,0.20%）;Experiment 2:The effects of polypeptide and amino acid with magnesium on grape yield and quality.A total of 6 treatments were set,including clear water（CK）,0.10%polypeptide（P2）,0.30%magnesium sulfate,0.10%polypeptide+0.30%magnesium sulfate（P2+Mg）,0.15%amino acid（AA）,0.15%amino acid+0.30%magnesium sulfate（AA+Mg）;Experiment 3:effects of compound application of polypeptide and amino acid with zinc on grape yield and quality,clear water（CK）,0.10%polypeptide（P2）,0.20%zinc sulfate（Zn）,0.10%polypeptide+0.20%zinc sulfate（P2+Zn）,0.15%amino acid（AA）,0.15%amino acid+0.20%zinc sulfate（AA+Zn）.[Results]（1）Different concentrations of polypeptide could increase the nitrogen content in grape shoots and grape yield.The nitrogen content in leaves treated with P2 and P3 increased by 12.04%and 9.07%respectively,and the yield increased by 13.16%and 19.75%.（2）0.1～0.20%polypeptide could promote the improvement of fruit quality.When the concentration of spraying polypeptide was 0.10%,the contents of soluble solid,soluble sugar and vitamin C increased by10.43%,43.97%and 20.0%respectively compared with CK,and the content of titratable acid decreased by26.09%.The optimum concentration of polypeptide spraying was 0.10%.（3）The photosynthetic rate of P2+12.06%was higher than that of P2+12.06%.The weight and yield of grape per spike increased by 16.56%and 17.93%compared with CK,and the fruit quality was significantly improved.（4）The net photosynthetic rate of grapes treated with P2+Zn increased by 35.54%,and the zinc content in shoots,stems and leaves increased significantly compared with P2 treatment,22.11%and 6.07%respectively compared with Zn treatment,which promoted the zinc absorption of grapes.（5）The yield of grape treated with P2+Zn increased by 10.99%compared with CK,and the contents of soluble sugar,titratable acid and vitamin C in fruit increased significantly,which improved the quality of grape fruit.[Conclusion]Different concentrations of peptides could increase the nitrogen content in grape stems and leaves.When the polypeptide concentration was 0.15%,the grape yield was the highest.When the polypeptide concentration was 0.10%～0.20%,the grape fruit quality could be significantly improved.The combined application of polypeptide with magnesium and zinc can promote grape photosynthesis and mineral nutrient absorption.The combined application of polypeptide and magnesium has the best effect on grape yield and quality.