EFFECT OF DIFFERENT TYPES OF FERTILIZERS ON THE GROWTH AND PRODUCTIVITY OF OLIVE TREES (Olea europaea L.) CV. ARBEQUINA

The study was done in the 2022 growing season on 16-year-old Arbequina olive trees cultivated at 6×6 m apart in clay sandy loam soil under drip irrigation system in a private orchard located at Zakho region, Duhok governorate, Kurdistan region, Iraq, to study the influence of different types of fertilizers on the growth and productivity of olive trees ( Olea europaea L.) cv. Arbequina. The experiment consists of twenty-seven treatments (three levels of soil application of chicken manure 0,5, 10 kg tree -1 , foliar application of three conc. of seaweed extract (Sea force) 0,10,20 ml L -1 and soil application of three levels of mineral fertilizer Blaukorn NPK (12:12:16) at level (0, 150, and 200g tree -1 ), mineral fertilizer was applied three times per season: First: at vegetative growth stage. Second: at full bloom. Third: after setting of fruits. Results indicate that soil application of chicken manure, especially at 10 kg tree -1 , and foliar spraying of Sea force at 20 ml L -1 significantly increased all studied characters (average leaf area, total chlorophyll content, number of flowers/inflorescences, fruit set %, fruit length, fruit width, fruit weight, total yield per tree, fruit total soluble solids (TSS%), Percentage of oil). Soil application of Blaukorn, especially at 200 g tree-1, significantly increased (average leaf area, fruits length, width and weight, and TSS). The binary and triple interactions of the study treatments on all the traits under investigation also showed a significant increase, particularly for the high levels of the study factors.