Evaluation of joint application of auxin and some chemical compounds to induce root in olive cuttings

In olive, the propagation through cutting is a simple and fast method for maintenance of genetic uniformity as well as precocity as compared to seedlings. However, difficult to root behavior of some varieties is one of the problems in this regard that has different reasons. Hence, to enhance the rooting ability of two olive varieties, the present study was designed and implemented. Materials and Applications: The experiment was carried out as factorial experiment in a completely randomized block design with eight treatments, three replications and two application methods. The hormonal treatments included Auxin (Indole butyric acid (IBA)) at the concentration of 3000 ppm, alone or combined with putrecine (Put: 100, 200 ppm), Phloroglucinole (PG: 125, 250 ppm), Tyrosine (Thyr: 250, 500 ppm). The application of treatments was done by two methods of soaking (immersion of cutting bases in a solution) or foliar application (spraying the treatments on the cuttings). The results showed that the reaction of two olive cultivars was different to the applied treatments, so that rooting percentage and longest root length did not affect the cultivar, but the other measured parameters were different in two cultivars. Root number, root length, fresh and dry weight of root in Mission was more than Koroneiki cultivar. The leaf area and also the survival rate of olive cuttings after transplanted to pot were higher in Koroneiki compared to Mission cultivar. The results showed that all treatments increased root number, fresh weight, dry weight, rooting percentage, leaf area and survival rate of olive cuttings significantly compared to control treatment, while the highest increase was observed in auxin treatments in joint with PG (250 ppm) or put (200 ppm) compared to control treatment. Regardless of the olive cultivar, the application of treatment method is also considered to be significant, Hence, the highest number of roots and their length, root fresh / dry weight were recorded in soaking Application while the higher number of new leaves, leaf area, number of new shoots and their length as well as rooting percentage were found in mico-cuttings treated though foliar spray. The results of this study clearly showed that the joint application of auxin with some chemical compounds such as phloroglucinol, putrescin and tyrosine can improve the rooting of olive cuttings and their joint application in commercial nurseries is recommended to propagate olive cultivars by cuttings.