Termografia na avaliação da temperatura de mudas de Tagetes erecta cultivadas em diferentes ambientes com e sem hidroretentor

Abstract

The production of seedlings within the protected cultivation reduces the effects of external factors, however, despite being considered a homogeneous environment, there are variations within this environment. Given the above, the objective was to use a thermography to evaluate the temperature variation within the protected environment and an interaction of the leaf temperature of Tagetes erecta as a function of different hydrogel functions. Two experiments were carried out. In the first experiment, lasting 22 days in a greenhouse with plastic cover, 972 plants were used, divided into three locations (east, center and west) and with three doses of hydrogel (H0 = 0g / L; H1 = 1.5g / L; H2 = 3.0g / L). For the analysis of leaf temperature, the methods of the thermo-hygro-anemometer-digital luximeter were used, with daily exposure from 8 days after germination, with 20 days after germination, an infrared thermometer was used and thermal images captured 14 days after germination and 20 days after germination using the FLIR ONE Pro® thermographic camera. In the second experiment, in a shade cloth greenhouse, 648 plants were used, divided into two locations (east and west) and with three doses of hydrogel (H0 = 0g / L; H1 = 1.5g / L; H2 = 3, 0g / L), lasting 10 days on a screen, the thermo-hygroanemometer-digital luximeter was used daily and images captured 10 days after germination through the FLIR ONE Pro® thermographic camera. In both experiments were evaluated as morpho-agronomic variables (plant height, fresh weight / plant, dry weight / plant and water rate (%)), canopy temperature and thermal index (Δ (Tcanopy - Tair)). With that, it was possible to realize that the infrared images can be used to identify leaf temperature. In addition, inside a plastic greenhouse or shade cloth there are different prices and this has influenced the production of vegetable mass. Lower temperature locations favored the lowest thermal index, which can indicate whether the plant is under water stress. Hydrogel favored a lower temperature and a lower thermal index in the protected environment with less variation in temperature.