Effects Of Different Calcium Preparations On Fruit Cracking Of Junzao

In the past ten years,after large-scale planting of jujube trees,the phenomenon of jujube fruit cracking has been plagued fruit farmers,which is a major problem that needs to be solved urgently in production.The test material in this article is the jujube from the 9th regiment and 12th company in Alar City of the First Division of the Corps.Two calcium preparations,EDTA-Ca solution and CaCl₂solution,are used to spray the jujube.Analyzing the relationship between exogenous calcium and fruit cracking in jujube will provide reference and scientific basis for effectively controlling fruit cracking and improving the ability of fruit trees to resist cracking.The main findings are as follows:（1）Through field observation,it was found that the natural fruit cracking rate of EDTA-Ca 1500 times solution and CaCl₂400 times solution was significantly lower than the control by 14.01%and 13.73%.The indoor cracking test showed that the fruit soaking and fruit cracking rate and water absorption rate were reduced by 71.24%and 35.51%respectively under the treatment of chelated calcium EDTA-Ca 1500 times solution compared with the control.The anti-cracking effect of calcium application in the young fruit stage-white mature stage is better than that in other stages.（2）The test results show that the activities of SOD,POD,and CAT gradually decrease with the increase of fruit maturity,and calcium application slows down the decline of SOD,POD,and CAT activities;Application of CaCl₂200 times solution,CAT activity was significantly higher than the control,different periods of calcium application of CAT activity changes significantly,high calcium treatment has a stronger response trend to CAT activity,the application of CaCl₂is more effective than EDTA-Ca.POD and SOD activity were significantly higher than other treatments when chelated calcium EDTA-Ca 1500 times liquid treatment.（3）After calcium application,the water-soluble pectin content in the jujube peel was significantly lower than the control,and the ion-bound pectin,covalently bound pectin,and cellulose content were significantly higher than the control.As the fruit approaches maturity,the original pectin inside the peel is transformed into water-soluble pectin,and the cellulose is gradually degraded.Compared with the control water-soluble pectin,the calcium treatment slows down the conversion and the degradation rate of cellulose is reduced.Chelated calcium EDTA-Ca 1500 times solution has better slowing effect than other treatments,and spraying in the young fruit stage-white maturity period is better than spraying in other periods.As the fruits continue to mature,the soluble sugar,starch,and protein content of the skin after calcium application significantly increased compared with the control.Exogenous calcium improved the fruit quality,increased the protein content,increased the resistance of the fruit,and promoted the balance of osmotic adjustment of the fruit.（4）After calcium application,the content of Ca in the peel and pulp of Junzao jujube increased significantly compared with the control.The content of Ca in the peel was significantly higher than that in the pulp.The content of Ca was the highest in the young fruit stage to the white ripe stage.The effect of multiple application of calcium on the absorption of calcium was more significant than that in a single period.The effect of applying calcium in the swelling period is more significant than in other periods.The content of K,P,Fe,Zn,B in the fruit was significantly higher than the control after calcium application,the content of K in the pulp was significantly higher than that in the peel,the content of Fe,Zn,and B in the peel was significantly higher than that in the pulp,and the content of Mg and P was different in the fruit Small;high calcium treatment in the middle and late stages broke the balance of mineral elements in the fruit,and the K content in the peel and pulp showed a gradual decrease trend;the P content had a higher absorption and transformation efficiency in the white maturity period and the expansion period,and the P content in the pulp was similar to The control showed a significant difference.The increasing trend of Mg content is related to the calcium concentration.High calcium inhibits the absorption of Mg ions,and low concentration promotes absorption.Appropriate calcium concentration can promote the absorption of Fe and Zn ions in the fruit.The effect of calcium absorption in the young fruit stage-white mature stage is higher than that in other periods,and it is positively correlated with the calcium absorption effect.（5）The thickness of waxy layer,stratum corneum,and epidermis after calcium application increased compared with the control,and the thickness of the stratum corneum and epidermis increased significantly compared with the control,which was significantly negatively correlated with the rate of fruit cracking.After calcium application,the stratum corneum cells are arranged uniformly and neatly;the structure of the epidermis is compact,the number of layers increases,and the shape is neat and clear;the cavity of the pulp tissue cells becomes smaller,evenly distributed,and the structure is regular.The chelated calcium EDTA-Ca 1500 times solution has the best effect,and the best effect during the application period is the young fruit stage-the white mature stage.