Effects of Putrescine Application and Fruit Thinning on Fruit Development and Return Bloom of Olive cv. Fishomi Tokhme-Kabki

In order to investigate the effects of putrescine on growth and development of olive fruits an experiment was conducted on Olea europaea ‘Fishomi Tokhme‌‌-‌‌Kabki’ trees in 2017 and 2018.The treatments included control (normal fruits and shotberries), normal fruits, shotberries, normal fruits with putrescine at 3 and 6 mM and shotberries with putrescine at 3 and 6 mM were sprayed on uniform branches two weeks after full bloom. Experiment was conducted in a randomized complete block design with three replications. Fruit set and physical characteristics of the fruit (average weight, length, diameter, flesh weight, pit weight and flesh /pit ratio of 10 fruits) were measured. The results showed that putrescine spraying increased total weight of normal fruits. Application of putrescine at 3 and 6 mM increased the weight and number of normal fruits at harvest time. Shotberry fruits caused the production of the highest total number of flower and complete flower in the next year compared to the other treatments. The normal fruit with different concentrations of putrescine had no significant effect on the formation of flower in the next year. Application of putrescine at 6 mM L-1 on shotberries showed that total number of flowers and complete flowers were increased in the return year.