Effects Of Two Growth Retardants On The Growth And Fruit Of Walnut In Trunk

Early-bearing walnut in Xinjiang has become one of the most important economic sources of dominant fruit trees and farmers’ income.However,early-bearing walnut beard fruit early and had a high yield,which result in the nutrient of the trees suffered severely malnourish,proned to premature aging phenomenon,in addition to the management of water and fertilizer,lacking of science and technology input in the production management,early-bearing walnut cannot make full use of nutrition,and generated a large number of leggy branches,in addition it wasn’t able to effectively control growth of the crown and the labor cost too much,all of that were also some important reasons.Plant growth regulators have been widely used in agricultural production because of their remarkable and highly effective characteristics.In this experiment,the Wen 185 as materials,with different concentrations of Paclobutrazol(PP333),DPC as the reagent,on walnut spraying treatment on the growth of walnut,light effect,chlorophyll fluorescence and quality,comprehensive comparative analysis using principal component analysis,the most effective type and the optimal concentration screening of two kinds of growth regulators,to provide a theoretical reference for the scientific and reasonable application of walnut production plant growth regulator.The main results are as follows:(1)Spraying Paclobutrazol and DPC had the effective of the diameter and internode length of the fruiting branch of walnut.Two kinds of growth regulators could increase the diameter and shorten the length of internode.The results of branch diameter and internode length to control the effect of the performance of PP333 is better than DPC,PP3332000 mg/L(P3)and 3000 mg/L(P4)concentration were better;the optimal regulation concentration of DPC was 200 mg/L(D1).(2)The photosynthetic characteristics of the leaf chlorophyll content of walnut leaves were increased by the two growth regulators.The results showed that the optimum concentration was 400 mg/L(D3)and2000 mg/L(P3)from the result of the effect of Paclobutrazol on chlorophyll content.The net photosynthetic rate(Pn)and stomatal conductance(Gs),the optimal concentration of Paclobutrazol was2000 mg/L(P3),DPC optimal regulation concentration was 400 mg/L(D3);Paclobutrazol treatment regulation of intercellular CO2concentration(Ci)of 500 mg/L(P1)reached the highest.Shrinkage performance amine regulation effect of 300 mg/L(D2)is highest;Paclobutrazol and DPC regulation of transpiration rate optimal concentrations were 2000 mg/L(P3)and 400 mg/L(D3).Two kinds of growth regulators had no significant difference in the control of leaf chlorophyll fluorescence kinetic parameters.(3)Compared with the treatment of Paclobutrazol and DPC,the density of walnut bud did not show significant difference.The number of units per bud was about 17,which was more stable.While the control effect of per plant with fruit number,the optimal concentration of Paclobutrazol was 1000 mg/L(P2),and DPC was 300mg/L(D2).(4)The effects of the two growth regulators on fruit weight and kernel weight were significantly improved.Paclobutrazol treatment to improve the walnut fruit weight and kernel weight optimal regulation of concentration were 500 mg/L(P1)and 3000 mg/L(P4),DPC to walnut fruit weight and kernel weight regulation affect the optimal concentration were 400 mg/L(D3)and 500 mg/L(D4).However,there was no significant effect on walnut kernel yield and shell thickness.(5)To some extent,two kinds of growth regulators improved the content of crude fat,but decreased the protein content,by comparison,3000 mg/L Paclobutrazol(P4)and DPC 300 mg/L(D2)is better;to nuts the tannin content of DPC 400 mg/L(D3),Paclobutrazol 1000 mg /L(P2)treatment effect;to some extent,Paclobutrazol and DPC inhibited the expression of total sugar content of sugar and cellulose;two kinds of growth regulators on saturated fatty acid and unsaturated fatty acid has little effect.To sum up,the optimum concentration of two plant growth regulators play a role in regulating the growth and development of walnut.The results of the principal compoment analysis showed that the effects of two kinds of growth regulators on the growth and development of walnut were better than contrast.The optimal concentration of PP333 was 2000mg/L,and the optimum concentration of DPC was 300mg/L~400mg/L.