Effects of humic acid applications on growth of different olive varieties sapling

In this study, the effects of increasing doses of humic acid and nitrogen applications on development and mineral nutrition of sapling were investigated with different olive varieties (Ayvalık, Gemlik and Manzanilla). The research was carried out at the Directorate of Olive Research Institute as a pot experiment. The experiment was set up with 5 replications and 1 sapling in each replication according to the split plot design. In the research, 5 humic acid (0, 100, 200, 300, 400 mg kg-1) and 2 N doses (0 and 100 mg kg-1) were used. Planting was carried out after mixing humic acid and N to the growing media (soil + organic mixture) during the transplantation. Sapling developments (stem diameter, sapling length, shoot length) were observed and measured at regular intervals during 12 months of growing period. At the end of the growing period, the saplings were harvested. Vegetative growth parameters and nutrient concentrations in different parts (leaf, stem, main, fibrous roots) were determined. According to the results of the research, it was observed that the olive varieties used in the experiment responsed differently to the applications. When the parameters examined were evaluated collectively, it was determined that the appropriate humic acid dose change according to the varieties and it could be 100 mg kg-1 in Ayvalık and Gemlik varieties and 200 mg kg-1 in Manzanilla variety. It was determined that N1H3 for Ayvalık, N1H1 for Gemlik, N1H4 for Manzanilla were most suitable in HA + N application.