Effect of Bagging on Shiranuhi Mandarin Fruit Quality during Growth and Storage

Doo-Gyung Moon, Sang-Woog Ko, Sung-Gap Han, Chun-Hwan Kim, Chang-Kyu Lim, Jae-Ho Joa

Soluble solids content and acidity are major determinants of fruit taste in citrus. It has been observed that fruit from top-grafted trees retain higher acidity than on-root stock in ‘Shiranuhi’ mandarin [(C. unshiu x C. sinensis) x C. reticulata]. In order to identify cultural practices that affect acidity in ‘Shiranuhi’ mandarin, we tested the effect of cover (fruit bagging) on fruit quality(size; soluble solids; acidity) from 50 days after anthesis, to 90 days postharvest in 7-8 year-old ‘Shiranuhi’ mandarin trees secondary grafted onto satsuma mandarin scaffolds on trifoliate orange rootstocks. Transverse diameter and longitudinal length were smallest in fruit covered with the black printed paper. No differences were observed between treatments in soluble solids content, but acidity in fruit juice was higher in non-bagged controls from 95 days after anthesis to 90 days postharvest. Citric and malic acid content was highest in the control at 125 days after anthesis. Mean temperature was 0.3-0.7℃ higher than ambient in fruit bags during fruit maturation. These results suggest higher temperature during growth and ripening may be responsible for lowered acidity in bagged ‘Shiranuhi’ mandarin fruit.