الفهرس 
REVIEW OF LITERATUREOnly 14 pages are availabe for public view
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Abstract
The present study was carried out for three successive seasons 2008/2009, 2009/2010 and 2010/2011 on fifteen years old of olive trees cv. Picual, The study included two experiments: The first experiment: was to detect the degree of the tendency of some olive cultivars (Picual, Manzanillo, Toffahi, Aggizi Shami and Koroneiki) to alternate bearing. The second experiment: was an attempt to reduce the degree of alternate bearing to the olive cv. Picual through: spraying gibberellic acid (GA3), spraying naphthalene acetic acid (NAA), fertilization by NPK over than the rates recommended by the Ministry of Agriculture and Lands Reclamation or spraying potassium nitrate (KNO3).
The results showed that, olive cv. Picual have the highest alternate bearing index while Toffahi cultivar gave the lowest alternate bearing index.
Spray of GA3 had a slight effect on increasing the buds content of indole acetic acid, increased the buds content of gebberllic acid and reduced the buds content of abscisic acid in comparison with control. Also, spray of GA3 resulted in reduce the buds contents of cytokinines (Zeatin - Kinetin - benzyl adenine). Spraying olive trees cv. Picual befor “on” year with GA3 at 75 ppm in first December led to the inhibition and slow the transition of buds to the floral state (buds thinning). As well as, spray the trees with GA3 impact on reducing the density of flowering, fruit set, and yield and led to an increase in vegetative growth and as improvement in fruit characteristics and increase the oil percentage .
Spraying olive trees in heavy crop year with NAA at 150 ppm after 30 days from full bloom led to improve the vegetative growth and reduced the yield and alternate bearing degree, also it had a positive effect on improving the fruit characteristics and oil content.
Fertilizing olive trees with 50% over NPK recommended doses in heavy crop year had a positive effect on improving the flowering characteristics, fruit set, vegetative growth and increase yield in application year and the next year and reduce the degree of alternate bearing and improves fruit characteristics and oil content.
Potassium nitrate sprays at 4% after final fruit set had an effect on the improvement of nutritional status, vegetative growth, yield and reduce the degree of alternate bearing, while Potassium nitrate sprays at 4% after pit hardening led to the improvement of fruit characteristics and oil content.
Therefore, it could be recommended to use GA3 at 75 ppm on first December for buds thinning or NAA spray at 150 ppm after 30 days from full bloom for fruit thinning or soil fertilization with 50% over NPK recommended doses or spray potassium nitrate at 4% after final fruit set and after pit hardening.
Key words: Olive, Picual, alternate bearing, gibberellic acid (GA3), naphthalene acetic acid (NAA), fertilization, potassium nitrate, hormones buds content, vegetative growth, folwering, fruit set, yield, fruit characteristics and oil content.