Effect of Foliar Spray of Humic acid, Ascorbic acid, Cultivars and their Interactions on Growth of Olive (Olea European L.) Transplants cvs. Khithairy and Sorany

Abstract

The study was conducted at the nursery of Malta station Duhok, Kurdistan region - Iraq, during the season 2011 to study the effect of ascorbic acid and humic acid on vegetative growth of two olive (Olea europaea) cultivars (Khithairy and Sorany ). The transplants were sprayed with four levels (0, 500, 1000 and 2000 mg.l -1 ) ascorbic acid and four levels of humic acid (0, 20, 40 and 60 mg.l -1 ). When transplant treated with 500 mg.l -1 ascorbic acid showed significantly effect of most characteristics, however foliar application of humic acid at 20 mg.l -1 significantly increase plant height, leaf fresh weight and leaf dry weight. Khithairy cultivar significantly dominated Sorany cultivar of the most studied characteristics. The interactions between cultivar and ascorbic acid showed significantly affected on the most characteristic studied, while Khithairy cultivar when treated with 500 mg.l -1 ascorbic acid significantly increased plant height, leaves number, leaf area and lateral shoot number. Cultivar and humic acid interactions showed that the Khithairy when treated with 60 mg.l -1 humic acid significantly affected on the most of the characteristic studied while the interactions between ascorbic acid and humic showed that the transplants when treated with 20mg.l -1 humic only increase significantly most characteristics. The interactions between (khithairy×0 mg.l -1 ascorbic acid ×60 mg.l -1 humic) increased significantly leaves number, shoot length and lateral shoot number. Key word: Humic acid, Ascorbic acid, Olive cultivar, leaf nutrient.