Evaluation of essential oil constituents plant nutrition elements and nitrate contents of wild collected and cultivated Origanum onites L. plants which applied different fertilizers

This project consists of two parts, namely the field experiment, and the area survey. In the field experiment, having beetarlan conducted under the ecologic conditions of Antalya, Oregano (O. onites L.) farming was made and harvested for three terms. Six different fertilizer ratios (Control, K2O, 5K2O/N,3K2O/N,K2O/N, and N) were applied in two different fertilizer levels (at 10 kg/decare and 20 kg/decare) throughout each farming period, and the influence of the trial subjects on the plant yield and soil properties was thereby investigated. The trial was constituted with 4 repetitions according to randomized blocks in factorial order. Among the fertilizers having been applied in different ratios, N applications were found as having increased the plant lengths, herbal yield, total chlorophyll, chlorophyll a, chlorophyll b, and NO3-N contents, and the essential oil yield as well more than the other applications. In the farming of the said plant, nitrogenous fertilization was deemed important particularly for the herbal and essential oil yields. Among the fertilizer mixes having been applied in different ratios in all three harvest terms, those with higher potassium content, such as 5K2O/N, was found as having increased the total phenolic substance, total flavonoid substance, antioxidant, and vitamin C contents of the plants. That is why fertilizers with potassium and nitrogen mixes should be taken into consideration for the increase of particular herbal quality features in the Oregano (O. onites L.) farming. Having the fertilizers levels examined among the trial subjects, it was found out that, 20 kg/decare fertilizer applications had made the plant length, spad chlorophyll values and NO3-N contents increased in all three harvests, while total phenolic and flavonoid contents had decreased in the meantime. In terms of the plant yields, and many other quality features, different fertilizer ratios were found to be effective more than the fertilizer levels. While the nitrogenous fertilization was important in terms of its yield increasing feature, potassium fertilization was important in terms of its quality increasing feature. In comparison to controls, different fertilizer ratios had increased the carvacrol content (as being the main constituent) of the essential oil of the Oregano (O. onites L.). While the highest carvacrol content in the plants had been attained from the 3K2O/N fertilizer application in the first harvest term, from the K2O fertilizer application in the second harvest term, and from the other fertilizer applications other than control in the third harvest term. Elevation of 0-100 m in Kaş, Demre and Serik-Aksu Districts of the City of Antalya in comparison of all three districts, despite Kaş District had been found in much better condition in terms of both plant nutrient contents, and soil features, such quality contents as phenol, flavonoid, antioxidant, etc. had been found to be low. On the other hand, the aforesaid quality contents, namely as phenol, flavonoid, antioxidant, etc. had been found higher in the Serik-Aksu Districts in comparison to the other districts. Upon examining the nitrate contents of the plants both from the field, and from the nature as well, despite the fertilizer application on the plants in the field, it was found out that, the plants from the field had been possessing nitrate contents similar to those of the plants collected from Serik-Aksu Districts, and that the fertilizer applications had no risky effect on the nitrate contents of the plants.