SUMMARYWe investigated the effectiveness of pre-drought treatment to acclimate a chilling-sensitive varietv-of maize (Errazu) against chilling injury. We tested two nnethods of applying drought: (a) withholding water during 17 d in perlite culture, and (b) suppressing water b>' keeping plants out of the nutrient solution at time intervals (2, 4, 6, 8 and 10 h) on five successive days in hydroponic culture. Drought treatments were applied to maize seedlings either in perlite or hydroponic culture before chilling (5 d at 5 °C and ISO/ano\ rtT^ s'^ photosynthetic photon fluence rate and then 5 d of recovery at 25 °C). Both experiments were carried out under low irradiance to avoid photo-oxidation damage during chilling. Plant growth (relative growth rate, RGB; net assimilation rate, NAK; leaf atea ratio, LAR; specific leaf area, SLA; and leaf weight ratio, LWR), percentage of necrotic leaf area, leaf relative water content (KWC), leaf water ("f,,,,,) and osmotic (^^) potentials, specific plant transpiration, total water absorption and COo exchange rate (CEB) were examined in drought-treated and non-treated maize seedlings during chilling and after a 5 d recovery period. RGR and NAR of droughted maize seedlings were higher than those of nondroughted seedlings during recovery, irrespective of the growth medium (petlite or hydroponic). Chilling-induced leaf necrosis was significantly lower in droughted than in non-droughted seedlings. Droughted plants had higher water status (higher leaf RWC, T,,,^, and 'V^) after 5 d of chilling, mamly owing to stomatal closure induced by drought. The CER declined to a similar extent in droughted and non-droughted maize seedlings on chilling, but during recovery droughted seedlings showed significantly higher CO, fixation rate than non-droughted seedlings. Leaf conductance of water vapour ig) and CO, intercellular concentration (C,) analysis led to the conclusion that chilling-induced CER inhibition was not due to a stomatal limitation. Droughted seedlings of maize had a better water use efficiency of photosynthesis (wuEp^) than non-droughted plants. We conclude that pre-drought treatment hardened the chilling sensitive variety of maize Errazu against chilling injury.