Representativeness of Scholander chamber measurements as a function of time after leaf removal

The objectives of the study were to determine the maximum tolerable period between leaf removal from a plant and the determination of leaf water potential (Ψ _l ), and to evaluate different ways of packing leaves after their removal from a plant (LR). Two experiments (Exp) were conducted in a randomized complete block design with four replicates, using bean, maize, and soybean crops. The predawn leaf water potential (Ψ _PD ) (Exp1) and the minimum leaf water potential (Ψ _min ) (Exp1 and Exp2) were determined. The maximum tolerable period between LR varied among species, ranging from 80 to 90 min for bean and soybean, and from 40 to 60 min for maize. A box with low interior air temperature and capable of blocking the effect of solar radiation reduced variation in leaf water potential. These results indicate that the determination of the Ψ _l in bean, soybean, and maize crops does not need to be carried out immediately after leaf removal.