Effect of preharvest bagging on fruit quality and postharvest physiology of pears (Pyrus communis)

Preharvest bagging of pear fruit (Pyrus communis L. 'Doyenne du Cornice') with micro-perforated polyethylene bags c. 30 days after full bloom did not affect fruit size and weight, density, maturity, and flesh content of N, P K. Ca. and Mg. Bagged fruit had a greener and lighter skin colour than non-bagged fruit, whereas the development of blush on the sunny side was not different between treatments. Bagged fruit had less cuticle deposition, whereas the wax content of the cuticle was not different between treatments. Fruit skin permeance to water (P'(H2O)) and fruit weight loss were not different between treatments. Permeance to CO, (P'(CO2)) and O-2 (P'(CO2)) were lower for bagged than for non-bagged fruit. Accordingly, internal partial pressure of O-2 (p(O2)(i)) was lower and internal partial pressure of CO2(p(CO2)(i)) was higher for bagged than for non-bagged fruit. However, these differences in fruit internal atmosphere between treatments were not large enough to result in significant differences in rates of skin background colour change and respiration during shelf life after 8 weeks in cold storage. With prolonged cold storage the differences between treatments in fruit skin background colour were reduced (bagged fruit de-greened more than non-bagged fruit) while the differences in firmness were increased (bagged fruit had more substantial softening than non-bagged fruit). Fruit bagging did not affect the incidence of senescent scald, senescent breakdown, and diseases after 6 months in cold storage followed by 7 days of shelf life.