Effect of Evaporative Demand on Water Relations of Citrus limon

Conductance, transpirational flux and xylem pressure potentialwere measured in leaves of well-watered 5-year-old lemon trees(Citrus limon (L.) Burm. f.) subjected to different levels ofevaporative demand. Increased leaf-to-air absolute humiditydifference generally decreased stomatal conductance and increasedxylem pressure potential, with a good correlation between thelast two parameters; but this trend was reversed on days withvery high evaporative demand, when stomata opened in spite ofthe low humidity. Citrus limon (L.) Burm. f., lemon, water stress, stomatal conductance, leaf water potential, transpiration, air humidity