COMPONENTES DE PRODUÇÃO E COMPOSTOS BIOATIVOS EM TOMATEIRO CULTIVADO EM DIFERENTES ESPECTROS LUMINOSOS

Abstract

Tomato is one of the main cultivated vegetables and an important source of mineral salts and bioactive compounds, particularly vitamin C, phenolic compounds and lycopene. These are compounds with antioxidant action of great importance for human health. There is scientific evidence that the content of bioactive compounds in tomatoes can be influenced by environmental variables, such as light intensity and light quality. The objective of the research was to evaluate the effects of variable quality of incident lighting on yield components, fruit quality and ecophysiological effects of tomatoes. The experiment was conducted in a protected environment, in a randomized block design (DBC), with four treatments (different types of photoselective screens) and three replications, consisting of 12 pots each, containing one plant per pot. The treatments consisted of photoselective screens ChromatiNet® Leno Pérola (35% shading), ChromatiNet® Leno Red (30% shading), Aluminet® (60% shading) and full sun (control). Productive variables of tomato were evaluated (productivity per plant, total productivity, number of commercial, non-commercial fruits and with apical rot and mass per fruit), agronomic variables (plant height, stem diameter and number of nodes), carotenoids, color of fruits, soluble solids, titratable acidity, chlorophyll content, electrolyte leakage (TLE), vitamin C, specific leaf area (AFE), photosynthetically active radiation (PAR) and ecophysiological evaluations. Data were subjected to analysis of variance and, when significant, submitted to Tukey's mean test (p<0.05), using the SISVAR statistical program. In general, the Aluminet screen was the one that most affected the performance of tomato plants. The total productivity, as well as commercial, non-commercial and black background fruits, was lower in the cultivation with Aluminet® , as well as the average mass per fruit. Plant height was not affected, but the stem diameter and the number of nodes was inferred in the cultivation in Aluminet® , with the cultivation in full sun with higher values. Carotenoids (B-carotene and lycopene), fruit color (L*, C* and h*), TLE and vitamin C were not influenced when photoselective screens were used. The use of shading screens is a cultivation strategy that brings productive advantages for the cultivation of mini tomatoes. However, the amount of shading should not be high, which could harm production, as happened with Aluminet® with 60% shading, which negatively interfered with most of the productive and physiological parameters of the BRS Zamir grape tomato