Continuous monitoring of plant “water stress” is particularly important in dry areas and has traditionally been accomplished by measuring soil moisture or developing evapotranspiration models to calculate the sum of surface evaporation and plant transpiration. But there is potential to improve water efficiency through new technology that more accurately senses when plants need watering.
The researchers randomly selected six leaves that were directly exposed to the light source and installed leaf sensors on them, avoiding the main veins and edges. They recorded measurements every five minutes.
This research could lead to the development of a system in which leaf pinch sensors send precise plant moisture information to a central unit in the field, which then communicates in real time with an irrigation system to water crops.
Daily changes in leaf thickness were small and no significant daily changes were observed as soil moisture levels moved from high to wilting point. However, when soil moisture was below the wilting point, the change in leaf thickness was more obvious until leaf thickness stabilized during the last two days of the experiment when the moisture content reached 5%. Capacitance, which measures the leaf’s ability to store charge, remains approximately constant at a minimum during dark periods and increases rapidly during light periods. This means that capacity is a reflection of photosynthetic activity. When soil moisture is below the wilting point, the diurnal change in capacity decreases and stops completely when volumetric soil moisture falls below 11%, indicating that the effect of water stress on capacity is observed through its effect on photosynthesis.
“The thickness of the sheet is like a balloon—it expands due to hydration and contracts due to water stress or dehydration,” Simply put, leaf capacity changes with changes in the plant’s water status and ambient light. Thus, analysis of leaf thickness and changes in capacity can indicate the state of water in the plant – a pressure well. »
Post time: Jan-31-2024