THE EFFECT OF DIFFERENT MOLECULAR WEIGHTS OF CHITOSAN ON THE YIELD, QUALITY, AND HEALTH-PROMOTING PROPERTIES OF STRAWBERRIES

Chitosan could be an alternative to synthetic plant protection chemicals commonly used in strawberry cultivation. The aim of this study was to determine the effect of chitosan with different molecular weights on the yield, health, and quality of Korona cultivar strawberries. The largest number of strawberries was harvested from plants sprayed with chitosan with a molecular weight of 50k kDa (611 g/plant). On the other hand, the largest (1017 g/100 fruit) and the firmest (225 G mm) strawberries were harvested from plants sprayed with chitosan125k kDa. Compared with the control, chitosan with a molecular weight >50 kDa also increased the contents of l-ascorbic acid and polyphenols and the antioxidant activity and improved fruit colour compared with the control. The plants were also more resistant to grey mould infestation. The experiment has shown that how chitosan interacts with fruit depends on its molecular weight, and chitosan with a higher molecular weight has a better effect on most traits determining fruit quality.