Ambiência e ácido giberélico para produção de mudas ornamentais

Abstract

The market for flowers and ornamental plants in the country provides income to small farmers, becoming a source of employment because it requires labor intensive, moving part of the Brazilian economy. The most cultivated species are chrysanthemum, rose, orchids and carnations, however, to a multitude of species with market potential. The present work has the objective of evaluating the interaction of the different screenings on the development of four species of ornamental flowers, together with the application of gibberellic acid. The experiment was carried out at the Universidade Tecnológica Federal do Paraná - UTFPR, Campus Dois Vizinhos, conducted at the Teaching and Research Unit - Viveiro de Produção. The experimental design was a randomized block design with a factorial of 4 x 5 x 2 (ornamental x shielded x gibberellic acid), with four replicates and 20 cells per experimental unit. Seeds of Calendula officinalis, Gypsophila elegans, Solenostemon scutellarioides, and Viola wittrockiana were seeded in 72 and 128 cell expanded polystyrene alveolar trays under a substrate of clay, sand and organic compost in a 2: 1: 1 ratio. After sowing, the trays were conditioned on black shadings with 35%, 50% and 80% shading, red, with 35% shading, and in full sun, with daily irrigation. After 30 days of seedling emergence, a solution of gibberellic acid at concentrations 0 and 300 mg L-1 was applied. It was possible to observe that, for the variables emergency (E%), mean time of emergence (MTE), rate of emergence (RE), leaf number (LN), leaf area (LA), lengths of overhead (LO), root (LR) and total (LT), and shoot dry matter mass (SDMM), the environments with netting influenced the results, raising them. There was interaction between the environment and the species used for the variable leaf area, and for calendula (C. officinalis), the highest LA was 80%, for coleus (S. scutellarioides) in a 35% screen. There was no difference between the environments in relation to LA for amor perfeito (V. Wittrockiana) and mosquitinho (G. elegans). In relation to the length, plants that were kept on shading had greater increase in height. The SDMM was superior to coleus, with 0.16 g in black 35% screen, compared to the other species and netting, demonstrating interaction between environmental and species factors. For root density (RD), the highest numbers were found in environments with 35% and 50% screenings. It is recommended the use of seedlings for the production of seedlings for the species studied. The use of black shading with 35% shading is indicated for the production of coleus. The exogenous application of gibberellin did not affect the development of the species studied.