Effect of Harvesting Time on Fruit Weight, Oil Accumulation and Productivity of Some Olive Cultivars (Olea europaea L.) in Tarrom Region (Zanjan Province)

In order to evaluate the effect of harvest time on fruit weight, oil content and fruit bearing in the next year in some cultivars of olive (Conservalea, Amygdalolia, Karidolia, Koroneiki, Arbequina, Zard and Rouwghani), an experiment was performed as a split plot in time based on CRD (Completely Randomized Design) with three replications at olive research station (Tarrom–Zanjan) during 2013 and 2014. Results showed that among the cultivars, Amygdalolia had the most (number of inflorescence and flower per branch, fruit weight and oil content). Also, highest percentage of complete flower formation, initial fruit set and final fruit set were obtained in cv. Arbequina. According to the effect of harvest time, the most fruit weight was observed at the third harvest. Fruit oil content reached its maximum level at fifth harvest time. Effect of harvest time on flowering and fruit set in the next year, indicated that the highest number of inflorescence and flower per branch as well as maximum percentage of complete flower formation, initial fruit set and final fruit set were obtained at the fourth , second and the third harvest time, respectively. Interaction between harvest time and cultivar on fruit fresh weight, oil percentage, inflorescence number, flower number per branch , complete flower formation percentage , initial and final fruit set were significant (p≤%1). Due to evaluated traits, the best olive fruit harvesting time to prepare canned and oil extraction should be late September and late October respectively.