ASSESSING THE EFFECTIVENESS OF DIFFERENT MANAGEMENT PRACTICES ON FRUIT SIZE OF ‘BLACKAMBER’ JAPANESE PLUMS

A trial was established to identify those management practices that have the greatest effect on fruit size of ‘Blackamber’ Japanese plums (spurred and upright cultivar). The orchard was planted at a spacing of 5 x 2 m, and trees trained to an open vase system.
Twenty four single tree experimental plots were established, which combined those extreme levels of different practices that are normally used in Chilean commercial orchards.
Experimental units were established according to a Plackett-Burman statistical design.
The practices chosen were: 25 or 40 m of fruiting wood, vertical or horizontal position of secondary branches, 5 or 6 main branches per tree, mainly young (1 to 2 years) or old fruiting branches on tree (2 to 4 years); extinction at 400 spurs per tree (yes or no); thinning 10 days before or 5 after beginning of pit hardening, eliminating 2/3 of current year shoots (yes or no); trunk girdling (yes or no), large or small fruit selected when thinning and 1.5 ppm TDZ spray when fruits were pea-size (yes or no). Additionally, we estimated the effect of leaving 250 or 400 fruits on the tree and harvest when firmness was 9.5 or 6.8 lb.
The most important effects that contributed to fruit size at harvest were harvest maturity (21 g), the selection of larger fruit when thinning (11 g), maintaining growing shoots (7 g) and spur extinction (400/tree) (6 g).

X International Symposium on Integrating Canopy, Rootstock and Environmental Physiology in Orchard Systems

G. Reginato, V. Egea

yield, crop load, hand thinning, thinning date, fruiting wood, extinction, shoot growth, girdling, TDZ, harvest maturity

https://doi.org/10.17660/ActaHortic.2014.1058.47