For the present thesis an experiment was carried out to increase the CBD level in three hemp species using different treatment methods. For this purpose, the influence of abiotic and biotic factors on the growth, harvest and drying of plant material was investigated. The evaluation was carried out by a HPLC analysis and a diode array detector. As Cannabis species, USO31, FINOLA and FEDORA17 were selected from the EU-Catalogue of agricultural plant species. For comparison, both flower and leaf were harvested and freeze-dried or air-dried. The results showed that the development of sex in Cannabis strongly depends on environmental factors such as light intensity, photoperiod, nutrient availability and stress conditions. Both the CBD content and the delta9-THC content continuously increased during the flowering phase until a maximum was reached and senescence was initiated. The two drying methods showed only minimal differences.