The effects of crop load reduction on apple (Malus domestica Borkh.) yield and fruit quality

Apple fruit thinning represents a mandatory practice by which we regulate crop load, fruit size and yields as the ultimate goal in fruit production.
The purpose of the present research was to clarify the impact of crop load reduction on fruit set, yield, and fruit quality of apple cultivars ‘Gala’, ‘Fuji’ and ‘Mairac’. Fruit clusters were removed after June drop and crop load levels were defined at 45 (low) and 80 (high) fruit cluster per tree in ‘Gala’ 80 (low) and 110 (high) for ‘Fuji’ and 45 (low), 80 (medium) and 110 (high) in ‘Mairac’. Fruits were sampled at harvest and subjected to analysis which included: fruit weight (g) and diameter (mm), fruit size distribution, firmness (N), starch index (1-10), soluble solids content (SSC), and sugars content, titratable acidity (TA). The number per tree at harvest, yield and yield efficacy was correlated with crop load level, while the highest fruit weight was obtained at the low crop load levels in all cultivars.
Fruit size distribution shifted to the higher class categories at the lower crop load levels.
Fruits were softer and the starch index was higher at lower crop loads in ‘Gala’ and ‘Mairac’, presuming the advanced maturity.
Fruits SSC and TA were the highest in ‘Mairac’ among cultivars, with the highest levels at the highest crop load.
In ‘Gala’ and ‘Fuji’, SSC and total sugars content were higher in fruits at the lower crop loads.

V Balkan Symposium on Fruit Growing

N. Magazin, G. Barać, M. Milović, J. Kalajdžić, B. Milić, Z. Keserović

thinning, fruit cluster, fruit weight, SSC, TA, fruit firmness

https://doi.org/10.17660/ActaHortic.2026.1449.41