Articles
THE STORAGE QUALITY OF APPLES AFTER FRUITLETS THINNING
The literature concerning the influence of thinning on apple quality at harvest is voluminous.
However, the information concerning the storage quality of these apples is very sparse.
During 20 years lasting experience with fruitlets thinning we noticed that storage quality of apples depended on the time and effectiveness of thinning, kind and concentration of chemicals used as well as on apple cultivar and year of trial.
The mineral content, flesh firmness, soluble solids content and physiological disorders after hand thinning and chemical thinning by use of NAA, urea alone or in mixtures with NAA, BA and CPPU on different apple cvs. were determined.
Generally, it was found that hand thinning performed after June drop (at the end of June) often increased firmness and sugar content but could also increase bitter pit incidence in storage.
Thinning by applying NAA soon after bloom didn’t change Ca content and storage quality.
The mineral content and storage quality of apples after use of urea depended mainly on its concentration and cultivar to which it was applied.
BA often increased firmness and soluble solids content during storage and decreased rotting and shrivelling of apples.
However, it increased brown core incidence.
The influence of CPPU on storage quality depended on the concentration and time of thinner application and on the apple cultivar.