Calibration of Beta gauges for determining leaf water status.

The recent development of beta gauges for the indirect determination of the water status of plants has had a widespread impact on plant ecological-physiological research. Calibration of these instruments has, however, been tedious and cumbersome, involving repeated simultaneous measurements of beta absorption and leaf water content. This procedure can be much simplified, as long as the beta absorption at a single known relative water content is measured, together with the turgid and dry weights of a sample of leaf discs.