Crop Load Effect on Productivity and Quality Parameters of Sweet Cherry (Prunus avium L.)

A field trial was conducted over three years in sweet cherry (Prunus avium L.) orchards located in Cova da Beira, Central-interior Portugal (40 degrees 10' N, 7 degrees 26' W). Cultivars 'Brooks' and 'Lapins' were grafted on P. mahaleb. The aim of this study was to determine the effect of fruit load on the course of fruit growth, productivity and physical and chemical fruit quality parameters. Tree productivity and physical and chemical quality traits of fruit (mean fruit weight, size, colour, firmness and soluble solid content) and juice (pH and total acidity) were measured. The course of fruit growth was similar in both cultivars. The relationship between dry matter accumulation, in the pulp and stone of the fruit, and thermal time, was captured in an empirical function. Crop load slightly influenced mean fruit weight, the soluble solids content and some colour attributes. Mean fruit weight, soluble solids content (SSC) and firmness (Durofel) decreased only beyond 10,000 fruits per tree.