A flexible apparatus for continuous recording of water uptake by plants

An apparatus for the continuous and automatic recording of water uptake by small plants or single shoots is described. The root system of the plant (or plants) to be investigated is submerged in a water supply vessel. The water decrease in the vessel is detected, and the water is replaced by pumping new water into the vessel in a stepwise fashion. The apparatus can be used for measuring the total amount of water taken up, and the rate of water uptake. A water uptake of less than 0·1 mm³ can be reliably determined in the present applications. An example from measurements of cyclic uptake of water by one single oat plant is given.