Influence of Cultivar, Harvest Date, and Selected Weather Conditions on the Essential Oils Content in Inflorescences of Hemp Cannabis sativa L

In the presented research work, the impact of two harvesting dates, temperature, and precipitation on the content of essential oils in inflorescences of three hemp cultivars in fresh and dry plant matter was assessed. Plants were harvested at full flowering and at full hemp seeds maturity. The highest content of essential oils in the dry matter of inflorescences was characteristic of the "Bialobrzeskie" cultivar in full flowering, and the smallest of the "Zolotonowska 13" cultivar, regardless of the harvest date. When the harvest was delayed from full flowering to full maturity, the content of essential oils in the fresh mass of the inflorescence increased. On the basis of the obtained results, it was concluded that the content of essential oils in hemp in the dry matter of inflorescence is determined mainly by the cultivar, while the harvest date and the influence of various weather factors modify these values. On the other hand, the content of essential oils in the fresh mass of the inflorescence depends mainly on the harvest date - the closer to full maturity, the higher their content.