Substrate based on agro-industrial waste and color of cultivation benches influence the production of Zinnia elegans

Among the various technologies that can be used to modify the environmental conditions in protected cultivation, the use of agricultural waste and the use of cultivation benches of different colors can be beneficial to plants, providing adequate plant development and giving greater sustainability to the production system. The study aimed to identify the potential for using substrate based on agro-industrial waste and colored benches as alternatives for the production of Zinnia elegans. The experiment was conducted in the experimental area of the Mato Grosso do Sul State University (UEMS), in the Unit of Cassilândia, using a completely randomized design arranged in a 3 x 5 factorial scheme (three bench colors x five substrate doses), with three replications of four plants for each treatment. The treatments consisted of three colored benches (white, red, and control - metal bench) and five substrate mixtures with different concentrations of agro-industrial waste (SBRA) and Ecosolo® (0, 25%, 50%, 75%, and 100%) in which Zinnia elegans was grown. The variables analyzed were plant height, length of internodes, the number of leaves, relative chlorophyll content (SPAD), stem diameter, flower diameter, number of petals, time required for flowering and shoot dry mass. It was found that the composition of the substrate affected most of the characteristics evaluated, except for internode length and stem diameter. The benches resulted in significant differences in relative chlorophyll content and number of petals. Adding increasing proportions of SBRA, provides greater vegetative growth and flower development in Zinnia elegans plants.