Thermal infrared remot sensing to discriminate soybean cultivars submitted to water deficits

Abstract

The shortage or excess of water produces anomalous vegetal metabolism. The water deficit is directly responsible for closing the stomat and consequently raising the foliage temperature, due to the decreasing of energy consumption associated to the decrease of water evaporation. This work has as objective the evaluation of thermal behavior among several soybean cultivars submitted to water deficit. In this study the experiment consisted of irrigated and nonirrigated plots, with three plots for each soybean cultivar. Canopy temperature determinations were done with a thermal infrared radiometer (PRT-5) and, simultaneously, air temperature was also obtained. The results demonstrated lack of differentiation among irrigated soybean cultivars. However, in the nonirrigated plots, the soybean cultivavars presented different thermal behavior, facilitating their separation into distinct groups according to their mechanism of water loss control. The results show the potential of thermal infrared remote sensing in studies related to the development and selection of cultivars resistant to dry spells.