Effect of Topping on Growth Development and CBD Content of Hemp (Cannabis sativa L.) in Pot Culture

In hemp (Cannabis sativa L.) cultivation, an important management factor is apical cut (topping) as this modulates plant architecture, plant biomass allocation as well as the yield of inflorescences and cannabinoids per plant and area. This study aimed to evaluate the effect of topping treatment on agronomical and quality characteristics of two monoecious hemp varieties, ‘Fedora 17’ and ‘Felina’, A greenhouse pot experiment was laid out in a completely randomized design (CRD), with two topping treatments (untreated and topped). The results revealed that plant height of both varieties was negatively affected by topping treatment and the higher values were recorded in the untreated (137.02 and 134.56 cm for Fedora 17 and Felina, respectively). The highest values of dry weight per plant and bud dry weight per plant were noticed for topped plants. In conclusion, the findings of the present study implied that the hemp had a positive response to applied topping for all studied cultivars and the CBD content was higher in topped plants as topping stress increased cannabidiol (CBD) content.