Effects On Zizyphus Jujuba Mill.'Huping Jujuba' Fruit Quality And Fruit Cracking Of The Different Calcium Preparation

Calcium is not only the essential mineral elements for the growth and development of Zizyphus Jujuba Mill.'Huping Jujuba', but also the important factor affecting its fruit quality and fruit cracking. Therefore, the study on the effect of Calcium on jujube fruit quality and fruit cracking can provide a theoretical basis for further research, while providing technical and project support for the economic benefit maximization in jujube production. The thesis is based on the experiment which used the inorganic calcium CaCl2(100 times), the calcium-specific chelating agent of EDTA (2000 times) and the organic calcium of Gaizhongbao (1500 times) as calcium preparations to spray on jujuba during its young fruit period, expansion period and white-mature period. After ripen, the relative quality was examined. The main results were as follows:(1) The sensory quality of fruit is effected by three kinds of calcium preparations in different periods, but the effect was not consistent. Compared with the control, sugar acid ratio, single fruit weight, fruit hardness, color index and edible rate are increased; Organic acids, water content, fruit shape index and fruit cracking rate are decreased. Spraying EDTA since young fruit stage decreased organic acids the most and increased sugar acid ratio the most. Spraying CaCl2 fruit cracking rate and fruit shape index was the lowest; coloring index, edible rate highest. Spraying Gaizhongbao, fruit weight, fruit hardness highest, water content was the lowest.(2) The intrinsic quality of jujube fruit is effected by three kinds of calcium preparations in different periods, and the effect degree was consistent.Compared with the control, total sugar, soluble sugar, reducing sugar, protein, Vc and phenolic content are increased. Among them, spraying EDTA since white-mature period, the content of total sugar, reducing sugar, protein, phenolic was the highest; Spraying EDTA since young fruit stage, soluble sugar content was the highest.(3) Fruit cracking is effected by three kinds of calcium preparations in different periods, but the effect was not consistent.Compared with the control, the content of total sugar, soluble sugar, sugar acid ratio, Vc and phenolic was increased; Reducing sugars, organic acids, protein content decreased. Spraying EDTA increased the total sugar, soluble sugar content. Spraying Gaizhongbao decreased organic acids the most, increased sugar-acid ratio the most. Spraying CaCl2 decreased reducing sugar content the most, increased the Vc content the most. Compared with normal fruit, total sugar, soluble sugar, sugar acid ratio, Vc, total phenols and flavonoids were higher than normal fruit; proteins, organic acids; anthocyanins was lower than normal fruit.(4) There is an inconsistency between the fruit cracking rate and fruit quality in three kinds of calcium preparations in different periods. A positive correlation exists between cracking rate and total sugars, organic acids, fruit shape index, protein, Vc; A negative correlation exists between cracking rate and fruit hardness, moisture content, edible rate and weight.