Abstract

This study was carried out at an olive farm located in Habbaniyah, 30 km east of Ramadi, the center of Anbar province in Iraq during the 2020 growing season to study the effect of foliar spraying with boric acid with three concentration levels 0, 0.5 and 1.0 g L-1 and seaweed extract under the trade name Alga600 with four concentration 0, 1.0, 1.5 and 2.0 g L-1 and their interaction in some of the vegetative and chemical characteristics of the olive c.v "Chemlali". The trees were sprayed till run-off on three dates. The first spray in the beginning of March before flowering and fruit set, the second spray after 1 month from the first spray after flowering and before the fruit set and the third spray after 2 month from the first spray after flowering and fruit set. The results showed the positive effect of foliar spraying with boric acid on all the vegetative growth characteristics of the olives, where the concentration 1.0 g L-1 significantly exceeded the rate of increase in branch length, number of leaves, total chlorophyll, dry matter ratio, carbohydrates, nitrogen, C/N and boron in the leaves compared with the control treatment (distilled water), spraying with seaweed extract at a concentration 2.0 g L-1 significantly outperformed most of the traits compared to the comparison treatment , while the interaction treatment (1 g L-1 Boric Acid + 2 g L-1 seaweed extract) was superior in the rate of increase of branch length and total chlorophyll, the percentage of leaves dry weight, total carbohydrates, leaves content of nitrogen and boron, compared to the comparison treatment, (1.0 g L-1 Boric Acid + 1.0 g L-1 seaweed extract) was significantly superior in the number of leaves compared to the treatment (0.5 g L-1 Boric acid + 1.0 g L-1 seaweed extract), which gave the lowest value in the number of leaves in olives.