| Quality production is a essential problem for fruit production.There are many factors affecting fruit quality,such as pruning,bagging,fertilizer and water management.In this experiment,the effects of pre-harvest water treatment and soil application of Potassium Fertilizer on fruit quality and leaf nutrient elements in ’Xinli No.7’ and "Akitsuge" were studied,in order to obtain the best pre-harvest water treatment,amount of potassium fertilizer and applying times,and provide theoretical basis for formulating a reasonable water and fertilizer management plan for orchard production.The main results are as follows:1.Three water treatments were carried out in ’Xinli No.7’ one week before harvest,among which moderate water control(relative water content of 45%-60%)improved the quality of fruit,while excessive irrigation(relative water content of 85%-100%)led to quality reduction.The fruit weight and water content of moderate water control decreased by 5.30%and 3.56%respectively compared with that of excessive irrigation;the soluble solid content of fruits in moderate water controlled treatment was 12.93%,27.64%higher than that of excessive irrigation;the total soluble sugar content of fruits in moderate water controlled treatment was significantly increased,22.50%higher than that of excessive irrigation;the total acid content of moderate water controlled fruit was 7.14%lower than that of excessive irrigation,and was mainly decreased by malic acid;the total acid content of moderate water control fruit was 7.14%lower than that of excessive irrigation The sugar acid ratio was 29.68,35.15%higher than that of excessive irrigation,and moderate water control was beneficial to the increase of aroma substances types and contents,with the total content of 698.63 ng/g,48.25%higher than that of excessive irrigation,among which the increases of alcohols substances were the most obvious.2.Among the three water treatments,the contents of N,P,Cu,Zn,B and Fe in the leaves of normal irrigation was the lowest,while the contents of Ca and Mg were the highest,which indicated that moderate water control and excessive irrigation were beneficial to the accumulations of N,P,Cu,Zn,B and Fe,but not conducive to the accumulation of Ca and Mg.The contents of K and Mg in leaves with moderate water control decreased significantly.The content of K of over irrigation treatment was 18.25 g/kg,23.14%higher than that with moderate water controlled treatment.The content of Mg in normal irrigation(relative water content was 60%-80%)was 5.83 g/kg,19.47%higher than that with moderate water controlled treatment.The contents of Cu,Fe and Mn in leaves with moderate water control increased significantly compared with other two treatments.3.The fruit qualities of ’Xinli No.7’ and ’Akitsuge’ soil were significantly improved by applying available potassium sulfate 30 days before harvest compared with CK,and the quality of ’Akitsuge’ fruits were improved more obviously after applying fertilizer.In the dose range of this experiment,the more the fertilizer applied,the more the quality improved.Among them,T3(0.75 kg per plant for 30 days before harvest)was the best.The single fruit weights of the two cultivars were significantly higher than CK by 12.29%and 7.43%,the contents of total soluble sugar were significantly higher than CK by 21.99%,16.09%,the sugar acid ratios were significantly higher than CK by 35.79%,9.62%;In three times of application,T4(0.5kg per tree,twice applied,30 days and 15 days before harvest)showed best effect.Sugar acid ratios in T3,T4 were significantly increased by 25.83%and 14.40%compared with CK,respectively;the contents of aroma substances in fruit increased,alcohols account for the highest total content of aroma substances,mainly the hexanol.With the increase of the amount of potassium application,the aroma species and total content of the two varieties increased.The total contents of aroma substances of ’Akitsuge’ in T3 were the highest,708.53 ng/g,while those of ’Xinli No.7’in T4 were the highest,626.30 ng/g.4.K,Ca and Fe contents in T4 leaves of ’Akitsuge’ were significantly increased by 28.07%,15.95%and 30.30%compared with CK,and K and Mg contents in T4 leaves of’Xinli No.7’ were significantly increased by 35.12%and 17.69%compared with CK,respectively.Zn contents in both varieties were significantly reduced.With the increase of potassium fertilizer application,the contents of nutrient elements in leaves first increased and then decreased.The contents of Cu and Zn in ’Akitsuge’ leaves decreased first and then increased,while the contents of other elements in ’Xinli No.7’ leaves increased first and then decreased,except that the content of N in‘Xinli No.7’ leaves decreased first and then increased.The results showed that the two-times-application was more beneficial for the accumulation of nutrient elements in leaves. |
