Variation in flower and fruit quality in ‘Royal Gala’ apple–the effect of flower position within a spur

Abstract

ABSTRACT‘Royal Gala’ apple flower clusters usually have 5–6 flowers, each capable of producing a mature fruit at harvest. This study looked at the variation in dry weight among the flowers within spur clusters and also the variation in fruit quality at harvest where only one specific flower was retained to harvest. The king or terminal flower had the smallest pedicel dry weight and length (17.7 mm compared to a mean of 23.3 mm for the other flowers). Receptacle dry weight was largest with flowers 1 and 2 (27 mg compared to a mean of 26 mg for the other flowers). Receptacle dry weight of the king flower was poorly correlated with its diameter, but was highly correlated with the weight of the receptacle of the other flowers within the same cluster. Spur flower clusters were tagged at flowering and reduced to one flower per spur and followed through to harvest. Earlier opening flowers had an initial advantage in terms of fruit diameter on 20 November but fruit diameter at harvest was better correlated with diameter recorded on 16 December. Length/diameter ratio was significantly higher in fruit from king flowers (0.96 compared to a mean of 0.91 for the other flowers). Seed number and weight did not differ among the fruit from different flowers. There was far more variation in fruit quality and flower dry weight between clusters compared to variation within a cluster.