Manejo da luminosidade na qualidade de hastes florais e soluções conservantes na pós-colheita de estátice

Abstract

The statice (Limonium sinuatum L.) is widely used as a floral stem in filling bouquets, dried flowers and in floral arrangements. Two field experiments were carried out, from February to December, at the Experimental Farm of the Universidade Estadual do Oeste do Paraná (Unioeste) Campus Marechal Cândido Rondon (PR), and a post-harvest one, from June to November, at Unioeste's seed laboratory. In field experiment 1, the seedlings of the five cultivars ('Dark Blue', 'Purple', 'Rose', 'White' and 'Yellow') were distributed under the mini shading environments with shading meshes in black, white and red. The aim of the study was to determine the best shading mesh color for statice production. The experimental design used was randomized blocks, in a 5 x 4 factorial scheme [(5 statice cultivars x 4 growing environments (black, white, red and no mesh)]. In field experiment 2, the seedlings of the four cultivars ('Dark Blue', 'Purple', 'Rose' and 'White') were distributed under the black shading mesh and number of 0, 1, 2 or 3 lamps. The design used was randomized blocks, in a 4 x 2 factorial scheme (0, 1, 2 or 3 x lamps with or without shading mesh. The aim of this study was to determine the best luminosity intensity and the necessity or not of using black shading mesh for statice production. In both experiments, the floral stems were harvested and evaluated every two days, the variables being: fresh stem biomass; stem length; stem diameter; number of stems per plant, number of tillers and number of corymbs per flower stem. In the post-harvest experiment, statice flower stems of cultivars 'Purple' and 'White' were subjected to six preservative products (ascorbic acid, citric acid, salicylic acid, gibberellic acid, sodium hypochlorite and silver nitrate). The aim of this study was to determine the best preservative product and the concentration to preserve statice stems. The longevity of the stems was evaluated every two days, on a previously defined scale of grades from 5 to 1. The experimental design used was completely randomized, in a 7 x 4 factorial scheme (preservative products + control x product concentrations). Regardless of the statice cultivar, it was possible to produce quality flower stems without shading mesh or with white mesh. Floral stems of cultivar ‘White’ are produced with white or red shading meshes. The cultivar 'Yellow' was the most productive. The cultivar 'Purple' produces quality floral stems under black shading mesh. It is not necessary to use LED lamps in the production of statice flower stems. The longevity of flower stalks between the two cultivars is different, depending on the preservative product used. Ascorbic acid provided 19 days of total shelf life for the cultivar 'Purple' with a concentration of 373 mg L-1, and sodium hypochlorite, 26 days, with a concentration of 3.1%. Salicylic acid did not affect the total shelf life of 'White', while citric acid did not affect the total shelf life of the 'Purple' cultivar. Gibberellic acid was the best preservative for the stems, providing a total shelf life of 38 days, with a concentration of 6.63 mg L-1.