EFFECTS OF DIFFERENT HUMIC ACID DOSES IN LEONARDITE ENVIRONMENT ON THE OIL PERCENTAGE AND FATTY ACIDS OF SUMMER RAPESEED (BRASSICA NAPUS SSP. OLEIFERA L.) UNDER CENTRAL ANATOLIAN CONDITIONS

Overuse and unconscious use of agricultural lands is causing reduction of organic matters in soil as well as degradation of its chemical structure. The use of chemical and farm manure, the use of organic, organo-mineral, soil adjusters and microbial fertilizers improve efficiency and quality of agricultural production and increase resistance to biotic and abiotic stres. The research was conducted in 2014 and 2015 under Central Anatolian conditions to determine plant ontogenetic phase and effective dose of humic acid (of 15%) + fulvic acid + K and leonardite treatments. The study used 4 treatment doses of humic acid (0, 5000, 10000 and 20000 ml/ha) at different ontogenetic stages of the plants during 8 leaved rosette growth (Z1), bolting (Z2) and flowering period (Z3). The results were compared to control plants. The results showed 40.14% oil on non treated control plants. Whereas, it rose to 50.85% when 10000 ml/ha of humic acid was applied. While the oil yield in control plants was 510.1 kg/ha in 2014, it was determined as 709.5 kg/ha when 10000 ml/ha of humic acid + fulvic acid + K was applied. The highest oleic acid was 69.55% after applicatiom of 20000 ml/ha. When the study results were evaluated together, it was revealed that humic acid+fulvic acid+K and leonardite increased the oil percentage, oil yield and fatty acids of the summer rapeseed variety Heros compared to the plants in control plot.The highest results were generally obtained during the bolting period using 10000 ml/ha treatment. Therefore, it was determined that the use of humic acid + fulvic acid + K and leonardite had positive effect on summer rapeseed varietyHeros in terms of the examined parameters.