Factors influencing fruit set and quality in different sweet cherry cultivars

The aim of this work is the characterisation of seven cultivars of sweet cherry grown at Murcia (Spain) by determining flower density, flower buds drop, number of developing flower buds and total number of flowers per node, fruit set and percentage of double fruits from 2004 to 2007. Also some attributes related to fruit quality, such as fruit weight, colour, soluble solids, total acidity and firmness were evaluated at different ripening stages. ‘Brooks’ shows high production of flower buds and an appropriate total number of flowers per node in different years, besides high levels of total soluble solids (TSS), ripening index and fruit firmness. ‘Burlat’ and ‘Somerset’ ranged medium values of most of the analyzed floral biology and fruit quality parameters. ‘Cristobalina’ had high fruit set percentages in all years of study (34-42 %), but the fruit size (7.26±0.30 g) and the fruit firmness values were low (1 N mm-1). The maturation period of ‘Marvin’ fruits was very short and at the commercial ripening stage these fruits showed the darkest red colour. In ‘Ruby’ the fruit set was very erratic and the percentage of double fruits was high. This cultivar presented a good ripening index and fruit firmness levels. ‘New Star’ is characterized by consistent high fruit set percentages (35-65 %), absence of double fruits as well as by good fruit size (12.7±0.54 g), colour and firmness levels (≈ 2 N mm-1).