ABSTRACT
Even though optimizing plant biomass or fruit production is the goal of irrigation, the plant is rarely the primary focus in irrigation scheduling techniques. Atmospheric techniques, where the plant is considered only tangentially when evapotranspiration (ETc) is estimated, and soil moisture monitoring with a wide variety of instruments are by far the dominant scheduling approaches in use today. The plant sits midway in the soil, plant, and atmospheric continuum and is the integrator of both the water status of the soil and the atmosphere. Moreover, virtually all plant processes that ultimately affect productivity are directly or indirectly linked to plant water status.[1] Although there are a variety of methods to measure or infer plant water status, few references in the literature propose the use of directly measured or inferred plant water status measurements in irrigation scheduling.[2-5]
The primary reason for this may involve the difficulties in interpreting plant water status measurements due to their interactions with evaporative demand and crop specific physiological factors. On-farm use of plant-based scheduling is exceedingly low. However, the increasing importance of agricultural water productivity and recent advancements in equipment and sensors for plant-based monitoring focus renewed interest in this scheduling approach.
