Plant water relations were measured 5, 7 and 11 days after
treatments began. The young fully expanded leaves were
sampled from one plant of each pot for measuring osmotic
potential (p) and relativewater content (j). For p, the leaf tissues
were immediately stored in a freezer at 20 8C until osmotic
potential was measured on expressed sap with a Fiske 1/10
Osmometer (Fiske Associates, Norwood, USA).