Four olive cultivars namely Manzanello, Picual, Coratina and Arbicon grown at Wadi El-Natroon area, Egypt under drip irrigation system in sandy soil were compared for optimizing their own yield as well as fruit quality parameters during 2001 (off-year) and 2002 (on-year), by application of an integrated and balanced fertigaion program including macro and micro-nutrients. Results showed that remarkable and significant differences in leaf mineral contents, yield and yield quality parameters were detected by using well distributed fertilizer program during the growing season of olive trees. The treated four cultivars attained higher yield in the “on” and “off” year than the control. The most outstanding olive cultivars having greater yield were Picual, Manzanello, Coratina and Arbicon in a descending order. Oil percentage was maximized with Picual olive while, Arbicon olive had the lowest value. Free fatty acids (%), Iodine number as well as Acidity (%) were minimized in Coratina olive and the lowest peroxide number as was in Picual olive. It is apparent that for planting Picual olive variety proved to be the promising one due to its greatest yield and best fruit quality specially when the actual requirements of macro and micro nutrients were used through the drip irrigation system.

The present work aimed to establish a protocol to minimize the potential effect of in-vitro preservation for 8 months of the two olive cultivars i.e Koronaiki and Kalamata. Three culture conditions (treatments) were chosen to investigate the most suitable one for minimizing somaclonal variations after the process of in vitro preservation. The conditions include MS medium plus mannitol, MS medium plus low temperature and MS medium plus naphthaline acetic acid. RAPD-based finger-printing was employed to determine the effects of the different chemical constituents and other culture conditions on the extent of somaclonal variations after 8 months of in vitro preservation at the DNA level. Four arbitrary primers (OPA-04, -07, -14 and -16) were successfully utilized to achieve such goal. The obtained results showed that Mannitol has more pronounced effect than the other investigated preservation culture and conditions for decreasing DNA alterations.