Estimation of daily carbon demand in sweet cherry (Prunus avium L.) production

In cherry production, the assimilate supply to the fruit is a crucial factor for growth and formation of quality parameters. The assimilate supply per fruit is limited by the relative growth capacity of trees, represented by the leaf area to fruit ratio (LA:F). In the present study, the required leaf area per fruit (LAdemand [cm² fruit-1]) of two sweet cherry cultivars, 'Bellise' and 'Regina', was estimated in 2018 and 2019, based on measured and interpolated values of fruit growth and fruit respiration rates. LA demand changed daily with an overall increase during fruit development, showing average values in stage III in 2018 and 2019 of 139 cm² and 175 cm² in 'Bellise', while 199 cm² and 212 cm² were found in 'Regina', respectively. Estimated LA demand for both cultivars was compared with measurements in cherries grown on girdled branches. In both years, estimated values exceeded measured values. In both years, positive correlation between LA:F and fresh mass, soluble solids content, and coloration was observed. The data obtained can be applied to evaluate the tree’s crop load for precise management.t growth and fruit respiration rates. LAdemand changed daily with an overall increase during fruit development, in 2018 and 2019 showing average values in stage III of 226 cm² and 294 cm² in 'Bellise', while 280 cm² and 229 cm² were found in 'Regina', respectively. Estimated LAdemand for both cultivars was validated with measurements in cherries grown on girdled branches. In 2018, estimated values were in the range of the measured values, while in 2019 estimated LAdemand was considerably higher. In both years, positive correlation between LA:F and fresh mass, soluble solids content, and coloration was observed. The data obtained can be applied to evaluate the tree’s crop load for precise management.