Method of Subjecting Growing Plants to a Continuous Soil Moisture Stress¹

Response of the water status of soybean to changes in soil water potentials controlled by the water pressure in microporous tubes

“…Studies of plant tesponse to dtought have been limited by the ability to conttol the water potential of the soil in whieh plants are growing. In an attetnpt to control soil water potential, several tesearchers describe a systetn in which plants were growti in a thin layer of soil held within a metnbrane that was suspended in solutions of known osmotic potential (Painter 1966;Tingey & Stockwell 1977). The Iitnitations of this systetn included the shott life of the tnembrane and difficulties in tnaintaining low soil water potentials due to the correspondingly low hydraulic conductivity of the metnbrane and soil.…”

Evaluation of a System for the Imposition of Plant Water Stress

“…Recent osmotic techniques have favored the use of PEG3 as an osmoticum (1 1,12,14,18). However, a measurable amount of PEG may be absorbed by the plant (1 1,14), and PEG has been reported to reduce phosphorous uptake (7,21,22), translocation (22), and the oxygen content of nutrient solutions (16).…”

Root Methods

“…In the apparatus of Lipiec et al (1988) ceramic tubes are connected to a water reservoir in a closed loop. An analogous experimental system is described by Painter (1966). The pump circulates water to prevent air collecting in the ceramic tubes, which would seriously limit the performance of the apparatus.…”