Olive Farming

Olive trees need be ordered 12 month prior to planting, from registered nurseries who are supported by the SA Olive Industry Association.

Planting distances will depend on circumstances, but traditionally trees are spaced 4 to 5 meters apart and rows are spaced 6 to 7 meters apart. Deep ripping and criss-cross delving over the entire area is assential as the trees are planted for life.

Trees are planted as follows:

A hole of about 1 cubic meter (1m X 1m X 1m) should be dug. The base of the planting bag is removed. The tree is then placed in the hole at a level slightly deeper than it is in the bag. When in position, the rest of the bag is removed. Normally the roots are left undisturbed, if they are growing around in a circle, they should be loosened lightly. Fill hole with loamy soil mixed with good compost. Use 1 cup of bonemeal (or some other source of organic phosphate) mixed in with this soil. In the Western Cape where the soils tend to be acidic, a cup of dolomitic lime can also be added to the mix. Water well. Fertilizers should not be placed in the hole at the time of planting since these could burn the roots.

Cultivar Choice

The choice of which varieties to plant is determined by the following:

• The market demand for the specific product (olive oil or table olives) the type of processed products required (black or green table olives)
• The adaptability of the cultivar to a specific region.
• The cross pollination requirements of the cultivars.
• The ripening period and harvest season.
• The availability of planting material

The olive is traditionally grown in areas with a Mediterranean type of climate to which it is ideally adapted. Such regions are typified by relatively cool winters where frost seldom occurs and hot dry summers.

The olive will also thrive under irrigation in drier areas. The olive requires sufficient winter chilling to enter rest and so initiate flower development, otherwise the tree remains in a vegetative state. Maximum day temperatures in June and July should not exceed 21ºC.

Frost can seriously damage olive trees, especially young trees and young shoots. Entire trees can die when exposed to temperatures of minus 10 ºC.

Olive trees are less sensitie to damage from moderate wind than other fruit trees.

The olive requires a well drained, well aerated soil which has been prepared according to recommended guidelines to a depth of at least 80cm prior to planting.

Very sandy soils have poor water retention capacity and will require intensive management in terms of irrigation and nutrition. Stony soils, especially with a high gravel content, are ideal. Heavy clay soils (above 35% clay) are unsuitable.

Young tree requires about 15 to 20 liters of water per week during the first growing season.

The irrigation requirements of a tree, I.e. the amount of water applied at a specific time and the frequency of application, is influenced by the following factors: the age and size of the tree, the season of the trees, the season and growth stage, the crop size, rainfall, temperature, relative humidity, wind, soil texture and the type of irrigation system. Double line drippers or microsprinklers are recommended.

One of the major causes of premature ageing of Mediterranean olive orchards is to be found in the application of irrational, inappropriate pruning
Dr Fausto Luchetti, Executive Director, IOOC, 1989

The main goal of pruning is to regulate production and tree growth by ensuring the formation and maintenance of a strong, healthy and fairly vigorous tree capable of bearing good crops of high quality fruit from an early age, annually, over a long lifespan.

During the first few years in the orchard, pruning is kept to a minimum. Only those branches which are in the way of others, or growing too near the soil surface are removed. There are different approaches to pruning and training olive trees. The most popular system, three to six main scaffold branches are selected to form a semi-open vase. All upright growth in the center of the tree is removed to improve light interception throughout the tree. A Traditional guideline for pruning, is that you should see light through the tree after pruning, and the tree should have a “lacey” look.

Table olives are picked separately and carefully by hand and placed in picking bags, or baskets, preferably lined with some material to cushion the fruit.Oil olives are usually stripped off the trees onto nets on the ground, but a far better system is to place an umbrella like net around the trunk to collect the olives, so that they are not in contact with the siol and minimal damage occures. Olives for green processing are picked when they turn from bright green to yellow green and the first fruit show a light pink blush, only fruit of the required size is harvested while the rest are left for later picking. Black table olives are picked when they have turned completely black, but before they soften and become overripe. Oil olives are harvested all at once when most of the fruit is optimally ripe. The oil content rises with ripening and is at its maximum when the fruit is too ripe to produce a qualty oil.