SHD are defined as all olive groves with a density of more than 80 olive trees per hectare and grown in dense rows.
The aim of the SHD orchards is to mechanize the crop as much as possible, i.e., to reduce the labor requirements for planting, pruning, harvesting, etc. and to achieve maximum production per hectare as quickly as possible.
SHDs started in the 1980s as an 'Italian' idea but were developed, expanded, and improved by the Spanish. Today they are considered one of the most promising forms of olive cultivation although they have a limited life span which is influenced by soil and climatic conditions, varieties, and cultivation practices.
Indicatively, the average lifespan of the SHD orchards is about 20-25 years, with an average annual fruit production of 10,000 kg/ha and an average oil yield of 2,000 kg/ha.
The most common planting distances abroad are 3,75 m to 4,5 m row to row and 1,35 m to 1,5 m on the row.
The most important factors in SHD orchards, after the appropriate choice of varieties and planting distances, are the tree shape and annual pruning, which are the most important factors in determining the economic viability of SHD orchards.
The most important and most widely used olive varieties in SHDs are:
These varieties are often referred to as patented varieties with properties that do not correspond to reality, such as the existence of a dwarf Koroneiki clone, etc. In any case, only the trademarks of some varieties have been registered within the EU, not their genotypes, so that there are no restrictions on their propagation.
Moreover, in recent years, in addition to the three (3) olive varieties mentioned above, other varieties with 'rights' - patents - have been promoted and used, most of which are new hybrids with limited agronomic evaluation.