Effect of Chemical, Bio-Fertilizers and Jasmonic Acid and Their Interaction on the Quantitative, Qualitative Characteristics of Olive Fruits Olea europaea L. Cultivar Surani

Abstract

The experiment was carried out in one of the orchards of Laylan district, 19 km from the center of Kirkuk city during the growing season 2021-2022 to study the effect of levels of chemical, bio-fertilizers and jasmonic acid on the fruiting characteristics and yield of olive trees Olea europaea L variety Sorani. Homogeneous vegetative growth, planted on 4 x 4 m lines and irrigated with well water in a drip irrigation system. Trees were sprayed with chemical fertilizers at three levels of 0, 3, 6 ml.L-1 and bio-fertilizers were added at three levels of 0, 20, 40 g.L-1. Trees were also sprayed with jasmonic acid at three levels: 0, 20, and 30 mg.L-1, at an average of 21 days between one spray and another. The experiment was designed according to a randomized complete block design (RCBD), The study reached the following results :- Spraying with chemical fertilizers, especially at the level of 6 ml L-1 (M2), led to a significant increase in studied characteristics, represented in the yield rate for one tree, fruit weight, fruit volume, pulp thickness, T.S.S, and Fruit oil percentage, which reached 21.97 kg.Tree-1, 1.72 g. Fruit -1, 1.77 cm3, 2.14 mm, 17.27%, 16.95% respectively, while the comparison treatment gave the lowest average for the aforementioned traits. Addition of bio-fertilizer, especially the level of 40 gm L-1 (B2), led to a significant increase in the studied characteristics, which are the yield rate per tree, fruit weight, fruit volume, pulp thickness, T.S.S and fruit oil percentage, which reached 21.90 kg.tree-1, 1.79 g.fruit -1, 1.81 cm3, 2.22 mm, 17.37%, 17.11% respectively, while the comparison treatment gave the lowest average for the aforementioned traits. Also, spraying with jasmonic acid at a level of 30 mg L-1 (J2) significantly increased yield per tree, fruit weight, fruit volume, pulp thickness, T.S.S and fruit oil percentage, which reached 21.26 kg.tree-1,1.64 g.fruit-1, 1.66 cm3, 1.96 mm, 16.90%, 16.57% respectively, while the comparison treatment gave the lowest average for the aforementioned traits. There was also a significant increase in the binary and triple interactions of the study treatments on all the studied traits, especially the high levels of the study factors.