Effect of Fruit Bagging on Quality of 'Conference' Pear (Pyrus communis L.)

Summary The effect of fruit bagging on the quality of ‘Conference’ pears (Pyrus communis L.) was evaluated over two growing seasons. The experiment was conducted in three treatments: bagged until harvest, where the paper bags were left on the fruit until harvest time (150 days after full bloom (DAFB)); bagged until –7 days before harvest, where the bags were removed seven days before harvest (143 DAFB); and the control – not bagged at any time. Bagged fruit were covered with paper bags in mid-June, 65 DAFB, at an early stage of fruit growth. HPLC analysis was performed for individual sugars, organic acids in whole fruit, and phenolic compounds in the skin and pulp. The year had considerable influence on observed fruit parameters. Bagging had a negative impact on sucrose and sorbitol content. The bagged fruit were brighter (higher L*) than the control fruit. The reduction of colour (increased L * parameter and hue angle around 95°) by bagging may have a negative effect on consumer appeal. In second growing season bagging reduced fruit weight to such extend, that fruit were under 110 g and therefore not marketable. Bagging of pear fruit increased some phenolic compounds in the skin. Epicatechin and caffeic acid contents in skin were highest in bagged fruit. Removing the bags seven days before harvest decreased arbutin content in the pulp and also total sugars in the whole fruit and therefore fruit may have poorer eating quality. Quercetin 3-O-rhamnoside content in skin decreased in both years among fruit bagged until harvest. We don’t recommend the use of bagging for ‘Conference’ pear in European growth conditions.