## 4 Discussion
At the same time, fruit fresh weight was increased at harvest under GA and GS treatments compared to the control. To some extent, this was also obvious regarding fruit dimensions, as girdling treatments (especially GS and secondly GA) increased the fruits' narrow diameter without significantly changing the fruits' shape, based on the length-to-diameter ratios. Similar increases in fruit fresh weight as well as in fruit dry matter at harvest have already been reported by other researchers in kiwifruit [6; 24; 26] as well as in other fruit species [31; 51; 52; 53; 54; 55; 56; 57], while there are also reports where girdling did not have a significant effect on grape berry weight [58]. The overall increase in the fruit weight and fruit dry matter is attributed to the increased supply of photosynthates to the fruits above the girdle zone [32; 34]. According to [PERSON] et al. [32], the modification of carbohydrate supply to the fruits, especially during the second stage of fruit sink development, leads to a significant increase of dry weight through the increased dry matter accumulation, as was shown in the present trial. This increased accumulation of carbohydrates in the growing fruit leads to the advancement of maturation [12; 18; 31; 32; 43; 59]. This was not clear in the present experiment, as TSS, chlorophylls, TA, as well as sugar concentration of the pulp and fruit firmness did not exhibit significant differences among treatments. Nonetheless, if one takes into account the absolute content of the aforementioned constituents of the fruit, then it would be clear that girdling increased their content per fruit (approximately 16.4% increase of the total carbohydrates per fruit under GA treatment compared to control). After the storage period, fruits produced under all girdling treatments presented a reduced firmness compared to the control, which indicated faster maturation under storage conditions, also supported by the highest TSS content and TSS versus TA ratio determined. The higher dry matter per fruit at harvest under girdling could have been the source for the higher TSS determined after the storage period. Significant post-storage effects of girdling on the fruits have been described [18], although the later research focuses on physiological disorders appearing post-storage. Similar significant increases during storage in the TSS content of fruits produced after girdling have also been reported in 'Jonagold' apples [60]. Improved storage efficiency of the fruits produced under girdling treatments has also been reported in various other species [57; 61; 62]. Phenolic compounds, as well as ascorbic acid, contribute greatly to the antioxidant profile of fruit, and this characteristic is becoming more and more desirable by consumers, aiming at bioactive enriched fruits, i.e., 'nutrafrufits' [16]. Girdling did not have a significant effect on the phenol content and ascorbic acid concentration of the fruit at harvest, but it significantly increased its antioxidant capacity, especially when girdling was performed in September (GS). Girdling has been found to affect fruit polyphenols in table grapes [54] as well as in cherries [63], mandarins [4], and plums [16], where this action has been attributed to the increases in L-phenylalanine, the substrate of phenylalanine ammonia-lyase, which is the key enzyme of phenolic metabolism. Once again, if one takes into account the overall fruit mass stimulation by girdling and calculates the overall phenol content of the fruit, it becomes obvious that girdling did increase the phenol content per fruit, as was also clearly shown in Figure 3. [PERSON] and [PERSON] [4] attributed such accumulation of secondary metabolites based on the growth differentiation balance hypothesis. Based on this hypothesis, the over-accumulation of carbohydrates to levels exceeding the demands for growth leads to the use of this excess carbon for the biosynthesis of carbon-based secondary metabolites, such as phenolic compounds.