SIX YEARS OBSERVATIONS ON APRICOT HIGH DENSITY PLANTINGS

An experimental High Density Planting for apricot (HDP) was established in 1981 for ‘San Castrese’ grafted on Myrobalan and trained to four systems: free spindle (FS), Ypsilon (Y), Intensive open center (IOC) and bent canopy (BC). Free spindle and Ypsilon were spaced at 4.50 m between the rows and at 2, 1.50 and 1 m along the row, while IOC was spaced at 2 and 1.50 m between the rows and at 2, 1.50 and 1 m and 1.50, 1 and 0.75 m along the row.
The bent canopy was spaced at 2 m within the rows and at 2, 1.50 and 1 m along the row.

Increasing tree density (from 1,111 to 7,644) resulted in lower yield/tree, fruit weight and trunk growth in all training systems, but increased yield/ha during the early years of cropping.
The closest spacings (row and tree line) in the IOC resulted in excessive canopy shading and more difficult orchard management which necessitated the removal of one row in two after five years of cropping.

Trees trained as free spindles had almost the same cumulative yields (74– 76 MT/ha) at lower or intermediate density (1,111 – 1,481 trees/ha) and a slightly higher yield (84 MT/ha) at density of 2,222 trees/ha.
Trees trained in the Ypsilon system had the greatest yield (94 MT/ha) at the highest planting density (2,222 trees/ha).

The BC trees had higher yields than the IOC system planted at the same distances.
The highest yield (120 MT/ha) was obtained at the intermediate density of 2,867 trees/ha.

An economic analysis revealed that the gross income due to the increased yields from higher numbers of trees/ha in the IOC was nullified by the greater cost for the orchard establishment if compared to the free spindle or Ypsilon systems.

At present the most interesting systems seem to be the bent canopy, Ypsilon and free spindle.

IV International Symposium on Research and Development on Orchard and Plantation Systems

R. Guerriero, G. Scalabrelli

https://doi.org/10.17660/ActaHortic.1989.243.51