The Effect of Humic Acid and Potassium Applications on Growth of Oil Seed Sunflower (Helianthus annuus L.)

In this study, it was aimed to determine the effects of different doses of K fertilizer and humic acid applications on yield, yield parameters (plant height, stem thickness, head diameter, 1000 grain weight, yield of grain and head, the ratio of oil in grain and protein, the ratio of hull-kernel) and on plant nutrient contents (N, P, K, Ca, Mg, Fe, Cu, Zn and Mn) of sunflower. The experiment was carried out in a farmer’s field in Söke, Aydın in 2014 and 2015 as a randomized blocks split plot design with three replications. Seeds of Sanay MR sunflower hybrid variety were evaluated under five different K fertilizer (0, 4, 8, 12 and 16 kg K2O da-1) and four different humic acid doses (0, 10, 20 and 30 kg da-1). According to the results; the increasing doses of K fertilizer and humic acid had significant effects on yield, yield parameters and on the content of plant nutrients of sunflower. In sunflower farming, application of humic acid in addition to the K fertilizers on high pH, low organic matter and low macro nutrient soils would increase the benefits of plant nutrients and positively affect yield and quality