Enhancing abiotic stress management for agricultural sustainability: IoT-driven real-time monitoring of tomato turgor pressure and with comprehensive assessments of growth parameters, crop yield qualities, and nutrient contents

The PRIMA 2018 SECTION 1 MEDITOMATO project utilized Internet of Things (IoT) technology to optimize irrigation management with saline water by monitoring real-time abiotic stresses, including temperature, drought, and salinity, in tomato crops. The experiment employed a pot design structured as a randomized complete block in three treatments to assess the response of tomato plants to three distinct salinity levels (T0 = 2.2; T1 = 3.3, and T2 = 6.6 dS m⁻¹). For continuous evaluation of climate parameters and leaf-turgor pressure, an iMETOS ECO D3Il device was installed, accompanied by two Yara Water-Sensors affixed to tomato leaves. The study measured growth parameters, conducted analyses on soil salinity, and assessed crop yield qualities and nutrient contents of tomato organs. The results revealed higher salinity, a decrease in pH, and increased Cl⁻ and Na⁺ concentrations in T2 compared to T0 and T1. Increasing soil salinity exhibited a reduction in growth parameters. T2 experiences a significant reduction in various morphometric parameters, including the number of lodges, average weight, average water content, caliber, both average width and length, and firmness compared to T0 and T1. In contrast, T0 and T1 demonstrate similar values, signifying a divergence in the response to different irrigation treatments. Moreover, T2 displays a significant increase in Brix (%), turbidity, and nitrate content. Turgor pressure was notably higher in T1 during flowering and increased with temperature up to 28 °C. Beyond 28.5 °C, turgor pressure decreased for both treatments. The Na⁺/K⁺ ratio increased with salt stress but remained lower in leaves than in roots. The IoT device demonstrated its reliability for real-time control of tomato water status under abiotic stress.