Tolerance and avoidance mechanisms to drought stress were studied in 6
-month-old plants of Newhall orange (Citrus sinensis (L.) Osbeck) and
Ellendale tangor (orange x mandarin hybrid) (Citrus sinensis (L) Osbec
k x Citrus reticulata Blanco) during a drought/rewatering cycle under
controlled conditions, Drought stress did not promote osmotic adjustme
nt, while elastic adjustment (tissue elasticity increase) was noted in
stressed orange and tangor plants. Both citrus plants showed a parall
el decrease in leaf conductance (g(1)) and leaf water potential (Psi(1
)) under water stress. Tangor plants had a more efficient water conser
vative strategy than orange, based on the characteristics of canopy ar
chitecture (lower canopy area and a more closed canopy with leaves nea
rly vertically oriented) together with a significant decrease in cutic
ular transpiration rates (TRc) under stress.