Study On Split Dressings Of Lane Late Navel Orange In Zigui,Hubei Province

In terms of citrus as perennial plant,fertilization frequency and time affect nutrient supply evenly annually and go or stay in soil.Mismatching fertilization frequency and time are becoming key cause of fruit yield and quality and nutrient efficiency in Lane late navel orange orchard in Zigui,Hubei province.Field experiment was conducted with Lane late navel orange as the tested material for two years,s,to analysis the effects of split dressings on fruit yield,quality and nutrient utilization of Lane late navel orange,with aim at matching fertilization frequency and time with nutrient requirement dynamics for higher fruit yield and quality,nutrient efficiency in Lane late navel orange orchard.The main results were as follows:(1)The effect of split dressings on fruit yield and quality of Lane late navel orange.Compared with the local farmer fertilization,earlier fertilization at fruit standing,filling and harvesting regardless of 2,3,and 4 times fertilization increased fruit yield of Lane late navel orange,particularly 3 times fertilization with earlier fruit filling and harvesting fertilization raised more fruit yield,while only one time fertilization and later fruit standing,filling and harvesting regardless of 3 or 4 times fertilization reduced the fruit yield.the treatment of one fertilization and late fertilization with s reduced The single fruit weight,fruit diameter and pericarp thickness were decreased by 3 or 4 times fertilization with later fruit standing,filling and harvesting fertilization,but increased with the earlier.The fruit V_c concentration and juice yield were increased but solube solid content was reduced by 3 times fertilization,the,,especially the fruit titratable acid concentration was reduced by earlier fertilization.4 times fertilization incereasd fruit titratable acid content,juice yield,solube solid and V_c concentration.According to the comprehensive score of principal component analysis,earlier and 3 or 4 times fertilization had the highest score and the best fruit quality.(2)The effect of split dressings on the nutrient concentrations of fruit,leaves and soil.One-time fertilization reduced nitrogen and potassium removals of fruit pulp and nitrogen removal of the fruit,but increased the phosphorus removal of the peel;later and4 times fertilization reduced the nitrogen concentrations in fruit and its pulp.Earlier fruit filling fertilization increased the nitrogen content of leaves,later fertilization declined the nutrients utilization of the trees and fruits,resulted in higher available nutrient content in soil.(3)Effects of time and proportion of germinating fertilization on fruit yield and quality of Lane late navel orange.The time and proportion of germinating fertilization had no significant effect on the fruit yield of Lane late navel orange.The germinating fertilization after fruit harvesting and germinating fertilization with 20%before fruit harvesting did not resulted in fruit regreening,while germination fertilization with 40%and 60%before fruit harvesting resulted varying degrees of fruit regreening.Germination fertilization before fruit harvesting increased single fruit weight,fruit diameter and solid acid ratio,but reduced fruit soluble solid and titratable acid concentrations.(4)The effects of time and proportion of germinating fertilization on growth and N,P,K concentrations of Lane late navel orange.Germinating fertilization before fruit harvesting increased leaf weight,leaf area and SPAD value of early spring shoots,and the N,P,K concentrations of spring shoot leaves.Germinating fertilization after fruit harvesting increased N,P,K concentrations of spring shoots leaves with no significant difference.Germinating fertilization with 60%before fruit harvesting decreased soil available N,P,K concentrations and total nutrient,P,K concentrations in the spring shoots in September.(5)Recommended split dressings for Lane late navel orange in Zigui,Hubei.Based on the results of fruit yield and quality,tree growth and nutrient concentrations,it was recommended that 3 times fertilization a year,germinating fertilization in March(before fruit harvesting),and fruit filling fertilization in June,the fruit maturing fertilization in September,with the proportion of 40:30:30.