Effects of Nitrogen and Zinc Fertilizers on the Yield of Flowering Shoots in Hypericum Perforatum

Hypericum Perforatum is a medicinal plant due to active materials such hypericine in plant leaves and flowers. In order to study the effect of nitrogen and zinc fertilize flower production an experiment as factorial set was arranged on the basis of complete randomized block design with three replications in 2012. This experiment carried out in greenhouse at the Research Station of the of Agriculture، University of Tabriz، Iran. Treatments were four nitrogen rates (0، 50، 100 and 150 kg. ha-1 pure nitrogen) and foliar application of Zn at three rates (zinc sulphate with a concentration of 0، 0. 003 and 0. 006). Results showed that the highest number of flower، essential oil harvest، number of lateral branches related to nitrogen fertilizer amount of 150 kg. ha-1 and Zinc fertilize 0. 006. maximum flower dry matter produced by nitrogen fertilizer amount 150 kg. ha-1 and Zinc fertilize 0/003.