Relationship between Fruit Cracking and Fruit Development,Water Potential of White Flesh Loquat

Fruit cracking in six-year-old white flesh loquat (Eriobotrya japonica Lindl. ‘Ninghaibai’) was studied at fruit development stages, and the fruit soluble sugar contents, relative water contents of soil and water potential of fruits were measured. The prevention effects on fruit cracking were also investigated by using covering plastic film, cutting roots and fruit bagging. The results showed that fruit shape index tended to decrease with fruit growth. When approaching maturity, the water potential in fruit and the relative water content of soil increased while the soluble sugar content in fruit reached the highest. After simulated heavy rain, fruit water potential had positive correlation with fruit cracking (R=0.941). The loquat fruits accumulated permeable materials such as soluble sugars and absorbed water from soil when fruits were nearly mature, it made fruit water potential increase, and then caused the fruit cracking. The inhibition effects on fruit cracking were the best by combination of covering plastic film, cutting roots and fruit bagging, in which the covering plastic film and cutting roots had large contribution.