Resumen
Water deficit is the major abiotic factor that limits crop productivity. Climate changes are likely to exacerbate drought stresses in the future. In the present work, we investigated the feasibility of using the Normalized Difference Vegetation Index (NDVI) combined with the canopy temperature and other physiological characteristics, such as chlorophyll content and gas exchange, to monitor soybean (Glycine max L. Merrill) plants differing in their drought response under glasshouse conditions. Additionally, the drought responses of the cultivars Embrapa 48 and BR 16 were assessed under conditions of natural drought, water deficit simulated by sheltering the plants from rain at the vegetative and reproductive periods and irrigation at field conditions. Remote sensing techniques could be used to initially assess the drought responses of soybean plants under controlled conditions. Additionally, we observed the relationship between the NDVI and several physiological characteristics, such as chlorophyll content, photosynthesis, stomatal conductance and transpiration. Therefore, the combination between remote sensing techniques and the assessment of physiological traits of plant materials at the same developmental stage and leaf areas is useful to accurately monitor cultivars presenting different drought responses.