The research focused on the evaluation of four breeding lines of feminized industrial hemp (Cannabis sativa L.), named CHk, G8k, G10k, and MERk, derived from selected parental genotypes. The experiments were carried out at two locations, Ljubljana and Krško, and across three sowing terms and methods: direct sowing of seeds in the field and transplanting of seedlings produced in two sowing dates in the greenhouse. We tested the response of plants to the agronomic practice of topping. Several morphological (height of plants, dry biomass of leaves with inflorescences, dry matter content, leaf/stem ratio) and biochemical parameters (cannabidiol – CBD and tetrahydrocannabinol – THC content) were analysed. The results show that the lines differed in their response to location, sowing date, and topping. The line MERk achieved the highest average plant height, G8k had the highest average inflorescence mass, and G8k also showed the highest leaf/stem ratio. MERk had the highest average CBD content, while CHk achieved the highest average CBD yield. Analysis of the parental genotypes revealed that the parents often had higher CBD content, but also higher THC levels. The greatest breeding progress was achieved with the line MERk, where high CBD content was maintained while THC was reduced to a legally compliant level.
|
