AIMS, METHODS, AND ADVANCES IN BREEDING OF NEW OLIVE (OLEA EUROPAEA L.) CULTIVARS
Olive culture is one of the oldest agricultural tree crops. As it was part of the traditional agriculture many local cultivars developed over the years. More than two thousand recorded cultivars, clones or subclones are still in use. Very few cultivars are grown commercially in more than one region or country. This is true particularly for the traditional olive growing countries.
The productivity of the olive tree in the traditional cultivation systems is relatively low. Long term average yields of 2.5 metric tons per hectare are considered high. On the other hand the production potential of many olive cultivars is 4–5 times higher when grown under intensive, irrigated, modern growing conditions (Hartmann, 1983; Crescimanno, 1965). However tree size and shape often changes with intensification as does also fruit development and oil accumulation (Spiegel, 1955).
For future viability of the olive as a commercial industry it is essential that production efficiency, uniformity and operation costs will be set on more economical basis (Lavee, 1983). Presently the olive industry suffers from a number of severe draw backs such as alternative bearing, low fruiting ability, expensive manual harvest, lack of varietal standardization, etc. Tree form, fruiting habits, fruit quality, production efficiency and resistance to diseases and