Th e Eff ect of Weather Conditions on Fruit Skin Colour Development and Pomological Characteristics of Four Apricot Cultivars Planted in Donja Zelina

Research was conducted on four apricot (Prunus armeniaca L.) cultivars of diff erent ripening periods in Donja Zelina, during 2010 and 2011 growing seasons. Trees were planted in 2006, and graft ed on a WaxWa rootstock. During 2010 growing season, ground- and over-colour of the fruit skin was measured from 97 to 114 days aft er full bloom (DAFB) for cultivars ‘Hargrand’, ‘Harlayne’ and ‘Harogem’ and from 81 to 99 DAFB for cultivar ‘Pinkcot®’ colorimetrically multiple times in intervals of three to four days using the change in ground-colour of fruit skin from green to green – yellow as a indicator for fi rst measurement determined by colour chart for apricots. At harvest in 2010 and 2011, fruit weight, height, width and thickness, fruit fl esh fi rmness and soluble solids content were determined as well. Th e most intensive changes were recorded in value a* of fruit skin ground- and over-colour in all four cultivars during the last 10 days before harvest in 2010, and ranged from 19.33 in cv. ‘Hargrand’ to 30.55 in cv. ‘Harogem’. Cv. ‘Pinkcot®’ and cv. ‘Harogem’ have developed higher b* values of fruit skin ground-colour then cultivars ‘Hargrand’ and ‘Harlayne’ in 2010, reaching values of 47.79 and 47.30, respectively. At harvest in 2011, values a* and b* were signifi cantely lower then in 2010 for all four cultivars, however bigger diff erences were recorded in cv. ‘Harogem’ and cv. ‘Pinkcot®’. For measured pomological characteristics at harvest, signifi cant diff erences were observed between cultivars in both growing seasons for all measured characteristics, except for cv. ‘Hargrand’. Th e biggest diff erence in fruit weight, height, width and thickness was observed in cv. ‘Harlayne’. Results suggest that high temperature fl uctuations and below average precipitations infl uenced the fruit skin colour and quality parameters of apricots in the sense of smaller chromaticity values.