Evaluation of substrates in the germination of Cannabis sativa L. seeds, up to the V3 stage, Cotopaxi, Ecuador

whose accumulation is strongly influenced by agronomic conditions in the early stages. Among these, seed germination and initial vegetative growth represent critical, yet little-explored, phases that determine the establishment of the plant and its subsequent productivity. The objective of this study was to evaluate the effect of substrate composition on seed germination and early vegetative development of C. sativa under controlled indoor conditions. A completely randomized design was used to evaluate four substrates (peat-based, coconut fiber, vermiculite, and humus) up to the V3 phenological stage. Germination percentage, plant height, root length, fresh biomass, and leaf area were quantified and analyzed using analysis of variance followed by Duncan’s multiple range test (p ≤ 0.05). Although all substrates promoted satisfactory germination, the peat-based substrate consistently promoted superior agronomic performance, including higher germination rates, greater biomass accumulation, and increased leaf area, while vermiculite significantly improved root development. Coconut fiber showed more variable responses, suggesting limitations related to nutrient availability. These findings demonstrate that substrate composition plays a decisive role during the early stages of C. sativa development, highlighting the importance of substrate selection in ensuring vigorous seedling establishment and providing practical guidance for optimizing nursery stage management in medical cannabis cultivation systems.