History of the Olive
It is often said that olive growing has not evolved, that centuries-old methods are still in use. But the fact that the hardy olive tree grows under harsh conditions does not mean that it would not respond favorably in a more fertile, better watered environment. When the olive is treated as a proper crop, production increases as, when compared to extreme situations, does quality.The olive tree is adapted to a climate of little rainfall and long summers in which precipitation is practically nil or of little benefit. The tree responds well to any amount of watering, although the best results are achieved through rational applications. The best time to water is during critical growth stages to favor of new shoots. It also allows the olives to ripen properlyin the fall.
The olive tree produces by extracting water and nutrients from the soil and utilizing solar energy to produce photosynthesis. Different types of soil, varieties, the use of the fruit for oil or table olives are all factors that cause variations in the amount of macro-elements extracted by crops.Harvesting is one of the most important operations in olive growing because of the repercussions it has on the quantity and quality of the year’s crop, on the next year’s harvest and on production costs, and it should come as close as possible to meeting the following objectives: fruit intended for oil production must contain the maximum amount of best quality oil; table olives must be at the stage of ripeness recommended for processing as black or green olives; the tree must receive as little damage as possible; and globally the operation must be cost-effective.
The Olive (Olea europaea; Heb. zayith, Gk, elaia) is an evergreen tree usually about 5m (16 ft) high, or much taller if un-pruned. The adult olive tree has a shallow root system which descends from the bottom of the trunk. The depth reached depends on the soil type.Young trees have a rather smooth silver grey bark, but with age the slender trunks become stout, fluted and knobby. Many old trees actually develop holes in the sides of the trunks which themselves are hollow; the holes result from old side branches rotting away. The numerous branches form a dense, shady tree which is favored by animals in the heat of the day. An enormously spreading root system extends around each tree in order to absorb sufficient moisture in the dry conditions in which it normally grows.
Hence the trees are well spaced out in the groves, being planted 11m (36 ft) apart, although irrigated trees are much closer together. Wide spacing allows plenty of light to reach the crown for best fruit ripening. Olive leaves are narrow and sharply pointed, grey-green on the upper surface and white on he underside owing to a complete covering of minute white scales, which help to keep down water loss from the tree. Flower buds develop among the leaves on the previous year's wood and they open in May. There are ten to forty flowers carried on each short inflorescence and the white flowers themselves are small with the parts in fours, but with only two stamens. Flowering begins when trees are at least five or six years old and they are said to be at their best between forty and fifty years old, although many large ancient trees still bear regular crops.
The cultivated olive tree is native to the temperate-hot climate characteristic of the Mediterranean countries,of which it is an autonomous species, and where it is principally located today. In the northern hemisphere it is found between the 30th and 45th latitudes. Although it does grow outside this area, it does not fruit successfully because of excessively high or low temperatures in the winter months. In the southern hemisphere most groves are found at similar latitudes.The olive tree can withstand low temperatures of -8 or -10 degrees C, and even lower as long as it is not subjected to them for many hours, thawing proceeds slowly and the tree is not in active growing period.During the growing stage, the olive tree is sensitive to low temperatures which can cause damage to twigs and secondary branches.
To ensure it fruits well, the olive does, however, need temperatures close to zero during winter, which induces vegetative rest. It withstands high summer temperatures well, and even lack of ground moisture, adjusting its growing activity to an essential minimum.