CWSI and soil matric potential as indicators to optimize irrigation in common bean production in different soil types

Resumen

To optimize water usage and increase production, it is important to use efficient irrigation control and management systems. The crop water stress index (CWSI) and soil matric potential have emerged as promising alternatives for irrigation management. In a greenhouse experiment, different irrigation rates were applied to two types of soil (Red Latosol and Red-Yellow Latosol) based on various water tensions (-10, -20, -25, -30, and -40 kPa). The experiment was conducted in a completely randomized design (CRD), in a 5x2 factorial arrangement (five soil water tension levels and two soil types), with four replications. Soil matric potential (SMP) and crop water stress index (CWSI) were evaluated, calculated from thermal images of common bean plants and meteorological data. Linear and non-linear relationships between these stress indicators were analyzed at different crop growth stages. The CWSI based on canopy temperature is an effective tool for determining irrigation requirements for beans at different growth stages. Linear and quadratic regressions were obtained between soil matric potential and CWSI for Red Latosol at growth stage R7 and for Red-Yellow Latosol at stages R5 to R8.

Keywords: canopy temperature, thermal imaging, water deficit.