Articles
A STUDY OF THE ACTUAL DURABILITY OF THE HARVEST PERIOD OF ‘GRAVENSTEIN’ APPLES
In integrated apple production in Südtirol, recommendations about dividing the apple harvest into several pickings are given as a means of improving fruit quality.
The degradation of starch in apples during ripening was studied by using the starch-iodine test to the apple cultivar ‘Gravenstein’ over a period of three years (1986–1988). Apples picked in five consecutive weeks (7 days intervals), covering the actual harvest season for the cultivar, showed a more or less uniform degradation of starch.
Based on storage trials including quality evaluations of representative samples of fruits, recommendations were given to pick ‘Gravenstein’ apples at a maturity development appearing as 50–60 per cent dark coloured cut surface when using the starch-iodine test.
A pronounced scattering of the quality within each fruit sample was revealed in the experiment when testing the fruit quality during storage.
Inhomogenity regarding maturity development within each sample were thought to be the main reason for this.
Analyses of the results regarding the starch-iodine test from this experiment supplied information about the scattering of the stage of maturity development in the fruit samples.
This offered data for a discussion of the benefits of dividing the harvest of this cultivar into two or more pickings.
To meet the requirement of picking apples of equal maturity it was recommended that the harvest of cv Gravenstein apples was divided into two or three pickings over a period of maximum three weeks.
The recommendations based on the results from this experiment are to be included in the guidelines for integrated production of pome fruits in Norway.