Effect of Biostimulant and Humic Acid on Tree Growth and Fruit Characteristics of Olive (Olea europaea L.) cv. Arbequina

This study was carried out on olive tree (Olea europaea L.) cv. Arbequina at the orchard in Grdarasha in Erbil Directorate of Agriculture Research center/Ministry of Agriculture /Iraqi Kurdistan Region, in order to study the effects of foliar application of biostimulant fertilizer with three concentrations (0, 2, 4 ml.L-1), and soil application of humic acid with three levels (0, 5, 10 m.L-1). The foliar spray and soil application were used on three dates (pit hardening, one month after first application and one month after second application) during the growing season on vegetative growth parameters, yield, fruit properties and oil content was studied. Thirty-six (36) of trees used in the experiment, Four branches per tree for each experimental unit with four replications. The experiment was arranged in (RCBD), with four replications. Trees were sampled at the harvesting stage and analyzed for morphology characteristics, chemical composition, and yield production. Data were analyzed by (SAS) using Duncan's Multiple Range Test at P≤ 0.05. Results showed that foliar application (Bio) and soil application (HA) significantly increased most of the parameters of olive trees such as on leaf area, Leaf dry weight, Leaf mineral contents (N, K, Mn and Zn), Fruit size, fruit fresh weight, Total yield per tree, oil content and Acidity % as compared with control.