The Performance and Potentiality of Monoecious Hemp (Cannabis sativa L.) Cultivars as a Multipurpose Crop

Given the growing interest in multipurpose hemp crop, eight monoecious cultivars were compared in a two-year trial for quantitative and qualitative yield in a Mediterranean environment characterized by a temperate and humid climate with hot summers. All hemp cultivars were evaluated for yield potential of (i) seed plus stem at seed maturity, and (ii) essential oil yield from inflorescences harvested at full flowering. The second goal was set to test the ability of cultivars to supply new seeds after the removal of inflorescence at full flowering. Among the cultivars, Fedora obtained the best results for seed (0.79 and 0.52 t ha(-1)) and vegetable oil yield (0.17 and 0.09 t ha(-1)) normally and with inflorescence removed plants, respectively. Futura, conversely, showed the best results for inflorescence (3.0 t ha(-1)), essential oil (9 L ha(-1)), and stem yield at seed maturity (8.34 t ha(-1)), as means across the two years. The cultivars studied generally reached the grain-filling stage during a period that was drier and warmer than the average of the same multi-year period, and this negatively affected seed quality. The oil fatty acid composition was mainly composed of polyunsaturated fatty acids (75% on average) and not affected by the cultivar. In conclusion, although the hemp grower should always clearly know the main production objective of the crop, the monoecious cultivars available today allow a multipurpose use of hemp crop, improving the sustainability of the cultivation activity.