Desenvolvimento de microverdes de coentro em função da força iônica da solução nutritiva e cobertura das sementes

Abstract

Microgreens are plants harvested between 7 and 14 days after germination. In general, they have food and nutritional importance. Coriander is promising among the species used as microgreens. This occurs because it has characteristics that qualify it for this class of crop, such as high concentration of nutrients, high acceptability by consumers, high production, good availability, and low cost of seed acquisition. This study aimed to evaluate the characteristics of growth, development, morphology, and yield of coriander microgreens sown on coconut powder substrate, covered or not by the same type of substrate after sowing and irrigated with nutrient solutions with different ionic strengths. The work was carried out in a growth room at the Olericulture Laboratory of the Department of Plant Science at UFC. The experiment was carried out in randomized blocks in a 3x2 factorial scheme, with the treatments evaluated being the combination of factors seeds covered or not covered with coconut powder combined with different concentrations of nutrient solution (a. distilled water, b. solution with 25% (1/4) of the ionic strength and c. solution with 50% (1/2) of the ionic strength), totaling 6 treatments and 4 repetitions/blocks. The propagation material used were fruit seeds of coriander cultivar 'Verdão' (TopSeed®) which were grown in trays. The trays were divided into two groups, in one of which the seeds were left without substrate coverage (seed-substrate) and, in the other, substrate coverage was added (substrate-seed-substrate). All treatments received distilled water until the 2nd day after sowing (DAS). In the 3rd DAS, the application of distilled water and nutrient solution was initiated to keep the substrate moist. The nutrient solution used was that of Hoagland and Arnon (1950) modified with a conductivity of 1.6 dS m-1 diluted to 1/4 and 1/2 of the ionic strength, according to each treatment up to the 13th DAS. At 14° DAS, the plants were harvested, and the following evaluations were performed: hypocotyl length, hypocotyl diameter, root length, cotyledon length, cotyledon width, leaf area, specific leaf area, fresh and dry mass of the aerial part and root and yield. Data were submitted to ANOVA and means test. The results showed that coriander microgreens showed better yields when the seeds were covered after sowing (substrate-seed-substrate) and irrigated with a nutrient solution of 1/4 and 1/2 ionic strength.