HIGH-DENSITY ORCHARDS IN KAZAKHSTAN
In experiments at the Kazakh Research Institute of Horticulture and Viticulture, 2-year-old trees of early-bearing apple cultivars on the dwarfing rootstock M.9 with a plant density of 8–9 000 trees per hectare produced a commercial crop of 8–10 t/ha in 2–4 years after planting either one-year-old trees or rootstocks which were then budded in situ.
The crops increased quickly and achieved 70 t/ha in the fourth year of bearing. In the treatments in which plant density was 4–4 500 trees per hectare the first yield was only half of that at 8–9 000 trees/ha, but they still achieved 40 t/ha in the fourth year of bearing.
The standard dwarf orchard in Kazakhstan is planted at 5 x 2 m. This gives its first commercial yield, of 4 t/ha, only in the seventh year after planting the rootstocks in the orchard. In the fourth year of bearing its yield is only 9.50 t/ha.
In the high-density variants the form of the tree crown was limited by cutting off one-year-old trees to a height of 90–100 cm and removing feathers to 20–25 cm. Thus the depth of the crown was approximately 65–75 cm. This tree-forming provided weak lateral branches growing from the central axis of the trees. Fruit-bud formation occurred on these laterals in the first year of growth. The habit of this fruit wall was maintained by contour summer pruning in later years. The better period for pruning is the end of