CONTROL OF INSECT PESTS AND DISEASES, MATURITY AND QUALITY OF 'IMPERIAL GALA' APPLES SUBMITTED TO BAGGING

This work was carried out to evaluate the efficiency of different fruit bagging materials to insect pests and diseases control, and its influence on maturity and quality of the fruits in an organic apple orchard. The experiment was conducted in a ten years old orchard of 'Imperial Gala' apple trees grafted on 'Marubakaido' rootstock (with a filter of EM-9), in Sao Joaquim, State of Santa Catarina, in 2007/08 and 2008/09. The apples were bagged after fruit thinning, with bags made of transparent micro-perforated plastic or non-textured fabric. The control treatment consisted of unbagged fruit. At harvest, fruits were assessed for damages caused by fruit fly (Anastrepha fraterculus), oriental fruit moth (Grapholita molesta), apple leafroller (Bonagota salubricola) and woolly apple aphid (Eriosoma lanigerum), incidence of the apple scab (Venturia inaequalis) and bitter rot (Colletotrichum gloeosporioides) diseases, as well as for physicochemical attributes of maturity and quality, and calcium (Ca) content of the fruit. Fruit bagging, regardless of the material used, reduced the damages caused by insect pests, but did not protect fruit against diseases caused by the evaluated fungus. Fruit bagging did not affect the development of the red color and Ca content of the fruit. In general, the bagging anticipated the fruit maturation process, characterized by the reduction on flesh firmness and skin and pulp texture, and by the increase of the starch-iodine index.