Studies On The Resistant Mechanism And Control Technology Of Fruit Cracking In Chinese Jujube

Fruit cracking is a major phenomenon in the mature period. It influences not only thequality and safety of fruits,but the income of the peasants. Up till now, cracking jujubebring serious losses for pessants. The study researched the crarking rate of different jujubevareties by investigating the natural fruit cracking condition in Cangxian GermplasmNursery of Chinese jujube, Cangxian, Hebei. And the study analyzes the water absorptionand water absorption rate of Manchengtuntunzao、 Sanbianchouzao,Jinsixiaozao,dalilongzao, xupujidanzao, damuzao. By determinating the fruit hardness, titratableacid,reducing sugar, total sugar, soluble solids, VC, fruit weight, vertical diameter,transverse diameter, fruit shape index, the study find their relations to cracking fruit; Onthe other hand, different spraying materials were put into use to prevent fruit cracking.The major results are as follows:1．Through investgate the cracking ratio in the nature condition,we divisioned moreanti-cracking varieties:changhong, xupujidanzao, damuzao and10-3and so on.2．The water absorption mete of sensitive cracking jujube fruits were not higher thanthe anti-cracking varieties. There was no relationship between the water absorption meteand fruit cracking. There was no relationship between the water absorption rate and fruitcracking.3Cracking fruit peel hardness of sensitive cracking jujube fruits is less than theanti-cracking jujube varieties in the mature stage. But peel hardness of different parts of afruit was not significant between them. The difference between peel hardness of crackededge and normal part was not significant.4Establish regression equation between cracking fruit ratio and size indexs andinclusions: Y=-37.1+10.1X1+0.8X2-3X3-1.4X4+0.2X5-2.2X6+36.7X8. The result findthat the9index were not all index that have an effect on cracking ratio.5.“Fanglie1hao” can significantly reduce pozao cracking rate. Spraying calciumnitrate can improve fruit weight, sugar content and reduce soluble sugar content, titratable acid content. Spraying GA3significantly increased fruit weight, the higher theconcentration, the higher the sugar content and titratable acidity,the lower the solublesugar. So the effect of GA3on the quality and safety of fruit is complicated...