The productivity of apple trees of the Jonaveld variety depends on the method and timing of crown pruning

Abstract

Goal. To study the influence of different methods and periods of crown pruning of Jonaveld apple trees on their productivity and quality of the crop. Methods. Statistical, correlational, field. Trees grown on rootstock M.9 T337 with a spindle-shaped crown were planted according to the scheme of 4x1 m. Three methods of pruning were used: traditional manual pruning, contouring with the formation of a fruit wall and contouring with manual finishing. The pruning was carried out in five periods: in winter (BBCH 0), in the pink bud phase (BBCH 57), in the flowering phase (BBCH 65), in the early summer period (when there were 10 leaves per growth; BBCH 74), and after harvesting (BBCH 93). Results. Contour pruning increased fruit yield by 10% compared to manual pruning, and contour pruning with manual finishing increased fruit yield by 18%, up to 76 fruits per tree. If the pruning was postponed to a later period, the number of fruits was significantly higher, but no statistically significant difference was found in the pruning options in the pink bud phase, during flowering, and in the early summer period. In the case of manual pruning, the weight of the fruit was 6–9% lower than in the rest of the investigated options, but no statistically significant difference was found between the options of contour pruning and contour pruning with manual finishing. Regardless of the method of cutting the crown, a clear tendency to increase the weight of the fruit was observed if the deadline for its execution was postponed. Conclusions. By performing contour pruning and forming a fruit wall, the yield can be increased by 15%, and by introducing contour pruning with manual finishing — by 30%. The highest productivity is provided by pruning the crown after harvesting — the yield increase is 27%.