Influence of color shading nets on ornamental sunflower development

Abstract

One of the many functions of sunflower (Helianthus annuusL.) is related to the use of its inflorescences in the flower market, which has guaranteed space for this species in floriculture in recent years. Sunflower has been highlighted as an ornamental plant for cutting. Studies have been performed aimed at reducing the size of this species, in order to improve its commercial production, which facilitates the production in field and in protected environments. The use of color shading nets can lead to growth manipulation and to the development of this species. The objective of this study was to evaluate the effect of full sun and the use of color shading nets Aluminet®, blue and red (Chromatinet®), on the development of ornamental sunflower cv. Pollenless Sunflower Sunbright. The studied variables were plant height, leaf number, diameter of the floral stem, inflorescence width and dry matter of leaves, stem and inflorescences. By the anatomical analysis of the leaves, it was possible to determine stomatal density, polar (DP) and equatorial (DE) diameters, as well as the relation DP/DE of adaxial and abaxial epidermis and leaf thickness. It is concluded that the best development of ornamental sunflower plants is observed in full sun and under Aluminet®.