Effects of Fruit Position in Canopy, Harvest Date and Bagging on Occurrence of Reddish-pulp Fruit in Peach

Abstract

The effects of fruit position in the canopy, harvest date and covering fruit with bags of different colors on the development of reddish-pulp, skin and flesh anthocyanin concentrations and flesh firmness were investigated in ‘Takei Hakuho’ peach (Prunus persica Batsch) fruit. In the first half of harvesting, the rate of reddish-pulp development was higher in fruit harvested from the upper part of the trees than in those from the lower part, whereas in the last half of harvesting the rate of reddish-pulp development had no relationship with fruit position in the canopy. There was no significant difference in the rate of reddish-pulp development among unbagged fruit and those in white and orange bags, However, fruits covered with orange and black bags showed a lower rate of reddish-pulp development at harvest. However, when fruits were stored for four days at room temperature the rate of reddish-pulp development was as high as that in fruit covered with white bags. The relationship between skin and flesh anthocyanin concentrations and flesh firmness was investigated in fruits covered with bags of different colors. There was significant negative correlation (P<0.001) between flesh anthocyanin concentration and flesh firmness and there was no significant correlation observed between skin anthocyanin concentration and flesh firmness. The relationship between skin and flesh anthocyanin concentration in fruit harvested from ‘Shimizu Hakuto’ peach trees varied largely among the orchards. These findings indicate that anthocyanin accumulation in peach skin is significantly affected by light conditions, such as fruit position in canopy and modification of light quantity through bagging with different colors, although the bags had little or no effect on anthocyanin accumulation in the flesh.