Influence of Agronomic Practices on the Bioactive Compound Production in Cannabis sativa L.

Industrial hemp phytochemistry is shaped by genetics and agronomic management, yet field studies integrating both remain scarce. The combined effects of cultivar, planting density, fertilization, and flowering time on cannabinoids, terpenes, and antioxidants in <i>Cannabis sativa</i> L. were evaluated. A field trial was conducted in Mallorca (2023) using two cultivars (<i>Enectaliana</i>, <i>Enectarol</i>) grown at two densities (Sector 1 ≈ 2.3 plants m^-2; Sector 2 ≈ 4.6 plants m^-2), with sampling from flowering onset (week 0) to week 5. In <i>Enectaliana</i>, fertilization (with vs. without) was tested. <i>Enectaliana</i> displayed CBD/CBDVA-dominated profiles, whereas <i>Enectarol</i> was CBG-predominant; THC remained consistently low. Effects were assessed via three-way ANOVA (Density × Time × Cultivar; Density × Time × Fertilization). The cultivar and time explained most of the variance, with interactions modulating magnitudes without altering effect hierarchies. Planting density acted as a second-order modulator, modulating concentrations without reversing cultivar rankings. Terpenes peaked early and generally declined as flowering progressed, with cultivar-dependent trajectories. Total phenolics and antioxidant activity (ABTS, FRAP assays) increased steadily until week 5, with density and treatment effects. In <i>Enectaliana</i>, fertilization effects were selective: ABTS values tended to be higher in unfertilized plants at the end of the cycle, FRAP results showed a density interaction, and cannabinoids exhibited non-linear responses to nutrient supply.