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The modifying effect of growth regulators on bud burst, flower bud formation and sex expression in olives varies greatly according to cultivar, concentration and time of application. Cycocel 200, 500 mg/l, ethephon 200 mg/l and SADH 2000 mg/l stimulated bud burst and flower bud formation in the 'Blanquetta' cv. A noticeable increase in the percentage of perfect flowers was obtained by 100 mg/l of kinetin, and 200 mg/l of Cycocel in the cv. 'Picual', Ethephon 200/1, Cycocel 200 mg/l and SADH 2000 mg/l considerably increased the percentage of perfect flowers in the cvs 'Blanquetta', 'Serrana' and 'Picual'. Treatments at green cluster stage were not effective

Two main categories of olive flowers were characterized. The first by presence of normal gynoecium and the other by the presence of rudimentary gynoecium. Complete flowers differed in shape of ovaries, style length, shape of stigma and density of hairs covering the stigma. Three types of aborted flowers were observed. The first type could be detected by lack of ovule integuments. The second by undevelopment of the style, outer tissues of the ovary and of the ovules, while the third comprised flowers of completely undeveloped female organs. No correlation existed between pistil abortion and the viability of pollen grains. Four groups of pollen grains regarding their stainability and three groups according to their shape were detected

The current study was conducted during seasons 2009 to 2010 to investigate markers of phase change in olive seedlings. Three year old seedlings from open pollinated Koroneiki cv. seeds were used. Morphological and anatomical markers of phase change were measured in each seedling. Differences between the studied parameters were detected. The obtained results showed that the seedlings were divided into three groups (Juvenile, Intermediate-juvenile, Mature). In general, seedlings of the mature group recorded higher values of plant height, stem diameter, number of lateral shoots and internode length. Also while leaf length, width, area and L/D ratio were higher in the mature leaves. Leaf anatomy revealed that leaves of the adult seedlings had higher percentage of upper mesophyll, and additional layer of palisade mesophyll beside the lower epidermis. The studied characteristics could be used as preliminary markers to select seedlings of short juvenility in olive breeding programs.