A, Vulnerability curve showing PLC in leaf xylem versus Ψ_{leaf} in field-grown rice. Even watered plants (solid symbols, *n* = 33) experienced up to 90 PLC. The drought treatment (white symbols, *n* = 41) was mild, perhaps because of accidental flooding; even so, nearly the complete vulnerability curve was obtained. Symbols represent different varieties: Bala (circles, *n* = 21), Moroberekan (squares, *n* = 17), Azucena (down triangles, *n* = 11), IR62266 (up triangles, *n* = 10), and Lemont (hexagons, *n* = 15). Weibull curves fit to the data of each variety were not different; therefore, data were pooled and fit to a single Weibull function (solid line). Insert, Same data grouped by measurement time (white symbol, 6–8; gray symbol, 9–11; and black symbol, 13–16). Letters above symbols indicate significant differences. Means and se, *n* = 22–29, *P* < 0.05, lsd test. B, Vulnerability curves of leaf (solid symbols) and stem (white symbol) xylem in greenhouse-grown rice of variety Azucena (circles) and IR64 (triangles). Means and se, *n* = 4–8 (leaves), *n* = 4 (stems). Lines represent a Weibull fit to the leaf data (solid and dashed lines) and to the stem data (dotted line). Vulnerability curves of the leaves were not different between the two varieties.

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