Cultivation of arugula microgreens: seed densities and electrical conductivity of nutrient solution in two growing seasons

Microgreens are young plants of vegetables crops that have stood out for their potential in culinary and their nutritional content. However, cultural practices such as seed density and fertilization methods have not been standardized yet. The aim of this study was to evaluate the seed density and electrical conductivity of nutrient solution in a soilless system of arugula microgreens in two growing seasons. The experiment was carried out in Porto Alegre, RS, Brazil, during winter and spring. The experimental design adopted was randomized blocks, with a factorial arrangement (4 x 4) formed by four sowing densities (50, 100, 150, and 200 g.m-2) and four levels of electrical conductivity, being 0.15, 1, 2, and 3 mS.cm-1. The evaluated characteristics were shoot height, shoot fresh and dry matter yield, and total soluble solids index. Growing microgreens without a nutrient solution is not recommended. The increase of electrical conductivity of nutrient solution and seed density promoted higher values of shoot dry matter yield and total soluble solids index. In winter, the best results were obtained using 150 g.m-2 of seeds at an electrical conductivity of 1 mS.cm-1. In spring, 175 g.m-2 of seeds was necessary, with a minimal electrical conductivity of 1 mS.cm-1.