This research was carried out at the Agricultural Scientific Research Center in Hama, in seasons 2020, 2021 to study the effect of foliar spray of seaweed extract on the growth and productivity of the olive tree cv. Kaisi, Where the foliar spray was
applied with seaweed extract called alga 600 in concentrate of (0.5 g/l) According to treatments: A0 control without spraying seaweed extract, A1 one spray one week before flowering, A2 one spray after fruit set, A3 one spray one month before harvest, A4 two sprays (before flowering and after fruit set), A5 two sprays (after fruit set and one month before harvest) A6, three sprays (before flowering, after fruit set, and one month before harvest) with the addition of ground fertilization according to the Fertilizer recommendation. The results of foliar fertilization showed a significant effect on the vegetative growth traits, as The treatment one month before harvest was superior to the rest of the treatments with a primary shoots length average 6.94 cm, while the control was 4.75 cm, while seaweed extract had a positive effect on the total number of flowers. Where the spraying treatment before flowering and after the fruit set contract was superior to the rest of the treatments, as the average number of flowers was 203.11 compared to the control with an average number of flowers 164.19, as well as in the percentage of fruit set, as the highest percentage of the contract when spraying treatment before flowering was 3.20% and in control 2.19% The results also showed a clear superiority in the productivity of the tree, especially the treatment before flowering and after the contract, Where the average tree productivity was 37.07 kg, and in the control it was 14.07 kg It was observed that there was a significant increase in the percentage of oil for the fruits, as a treatment a month before harvest was significantly superior to the rest of the treatments in both seasons, as the highest value of the oil percentage reached 20.28%, followed by a treatment before flowering, after fruit set and one month before harvest, with an oil percentage of 20.27 compared to the control 17.17%.
