Produção, longevidade e teores nutricionais do girassol ornamental submetido a água magnetizada em diferentes regimes hídricos

Abstract

In the face of scenarios of climate change and changes in rainfall patterns and water availability, it is essential to improve efficiency in the use of water. Several studies are being carried out in this regard, including subjecting agricultural crops to the use of water subjected to magnetic treatment. The objective of this study was: i) to evaluate the growth, biomass and longevity of flower stems and ii) to evaluate the contents of macro and micronutrients in the leaves of the ornamental sunflower Vincents Choice (Helianthus annuus L.) irrigated with different irrigation depths submitted to magnetic treatment. The research was carried out in a greenhouse of the Department of Water Resources and Sanitation at UFLA-MG, in a randomized block design in a factorial scheme. The treatments consisted of five irrigation depths (0.2; 0.7; 1.0; 1.3; and 1.6 of ETc - crop evapotranspiration) and two types of irrigation water (AM - magnetized water and AC - common water). The following characteristics were evaluated: plant height, stem diameter, inflorescence diameter, fresh and dry leaf and stem mass, fresh and dry inflorescence mass, postharvest longevity of flower stems and of micro and macronutrients in the leaf. Vegetative growth characteristics, biomass production, and post-harvest longevity as the contentes of N, P, K, Ca, Mg, Zn, B and Fe were not influenced by the type of water. However, water without magnetic treatment favored higher leaf concentrations of S, Cu and Mn. The increase in irrigation depth promoted growth, biomass, post-harvest longevity, higher leaf concentrations of N, P, Ca and Zn, and lower K, Cu and Fe. The leaf contents of Mg, S, B and Mn were not significantly influenced by the different water replenishments. Regarding the patterns of commercialization of cut flowers, blades equal to or greater than 0.7 of the ETc promoted the best classification of the ornamental sunflower.