Impact of hemp (Cannabis sativa L.) variety on the seed and stem yield, biochemical characteristics of the inflorescences and nutritional quality of seeds

Hemp is becoming increasingly popular, and many new varieties are coming onto the market to meet the requirements of different industries. In this study, the seed and stem yield, seed nutritional properties and the biochemical characteristics of the inflorescences of seven European varieties (Fedora 17, Futura 75, KC Dra, Monoica, Santhica 27, Tiborszallasi, USO 31) were investigated in a 3-year field trial. Futura 75 and Tiborszallasi stand out as varieties with the highest potential in the conditions of the experiment (humid continental climate with oceanic influences, heavy soil). Futura 75 achieved the highest seed yield (505 kg/ha dry matter), stem yield (8 036 kg/ha fresh matter), protein yield (140 kg/ha) and oil yield (181 kg/ha). There were no differences in protein content (average 21.0%) among varieties. The total unsaturated fatty acid content was as high as 87.6% at Tiborszallasi. The best ratio between omega-6 and omega-3 fatty acids was 3 : 1 in Tiborszallasi, which had also the highest oil content (30.2%), the highest total phenolic content (2.8 mg caffeic acid (CA)/g) and the best antioxidant potential (6.69 EC50 DPPH (2,2-diphenyl-1-picrylhydrazyl) mg/L). Most varieties had higher cannabidiol and tetrahydrocannabinol contents in the inflorescence at seed maturity (from 0.22 to 3.3 for cannabidiol (CBD) and from 0.00 to 0.32 for tetrahydrocannabinol (THC)) compared to full flowering (from 0.17 to 4.33 for CBD and from 0.00 to 0.52 for THC, on average 2.64% for CBD and 0.19% for THC), presenting an opportunity for dual-purpose use.