Abstract
Despite the nutritional and commercial significance of microgreens, well-defined technical parameters have yet to be established for their cultivation under different climatic conditions. This study aimed to determine the effects of seed density and nutrient concentration on mustard microgreens with soilless cultivation. The experiment was conducted in a greenhouse in Porto Alegre, Rio Grande do Sul State, Brazil, during the winter and spring of 2021. A randomized block experimental design was adopted, with 3 replications, using a 4×4 factorial scheme, consisting of 4 seed densities (50, 100, 150, and 200 g m-2) and 4 nutrient solution concentrations (0%, 50%, 100%, and 150%; corresponding to electrical conductivities of 0.15, 1.0, 2.0, and 3.0 dS m−1). Evaluated variables included the shoot height, fresh and dry shoot mass, and total soluble solids index. Winter cultivation was primarily affected by reduced radiation and lower temperatures in the protected environment. Under winter conditions in Rio Grande do Sul, mustard microgreens did not meet commercialization standards regardless of the seed density or nutrient concentration. In contrast, during spring, the recommended electrical conductivity was 2.00 dS m−1, and the optimal seed density was, at least, 150 g m−2.