Nitrogen Composition during Vegetative and Generative Growth Stages of Two Origanum Taxa from Turkey

Origanum onites and Origanum vulgare ssp. hirtum were collected from Balikesir, on the north west of Turkey. The nitrogen contents in organs such as root, stem, leaf and flower of Origanum onites and Origanum vulgare ssp. hirtum taxa in vegetative and generative growth stages were investigated. Nitrogen analyses of soil and plant samples were carried out according to the Kjeldahl method. It was found that the nitrogen content among organs of Origanum taxa changed in vegetative and generative stages, and that the soil and plant samples possessed a higher nitrogen content in vegetative stage than in generative stage. The highest nitrogen content had the flower, followed by leaf, stem and root, respectively. Furthermore, it was observed that the nitrogen contents of these Origanum taxa were not very different, and that the nitrogen content in root and stem was deficient and that in leaf and flower was enough for plant nutrition. In addition, there is an important relationship between the nitrogen amounts during the vegetative and generative growth stages of O. onites and O. vulgare ssp. hirtum taxa. Morever, there was an important correlation between the nitrogen amount in soil and plant.