ETHEN CONCENTRATION OF APPLE FRUITS IN RELATION TO INSERTION ON TREE AND SELECTED RIPENING SYMPTOMS

During a period of two years the ethen concentration in the seed cavity of 'Golden Delicious' fruits of a single tree were analysed separately at three harvest dates. The location on the tree and some ripening parameters were also determined. In particular the variability of the ethen concentration was investigated and correlated with the other ripening parameters. The ethen of each single fruit was related to its insertion on tree and to other ripening parameters were analysed. The variability of the ethen concentration increased as fruits approached the optimal picking dates. Methods for estimating ethen concentrations by means of sufficient large samples of individual fruits allow the classification or calculation of the median or average value after eliminating of the extremely high values. This would possibly be a more informative method than measuring from bulk sample (Head-Space Method). Fruits with high ethen concentration can not be discerned and separated according to their external ripening symptoms before ethen is analysed or before storage is starting. The accidental distribution of ethen concentration of fruits was independent to their location in the tree which makes it impossible to differentiate between several fruiting zones.