Brakish water and physiological aspects of artichoke.

Results of a trial carried out on artichoke cv. Orlando to study the effects of salinity on net photosynthesis (NP), transpiration rate (T), stomatal conductance (gs) and photosynthetic water use efficiency (WUE) at leaf scale, are reported. Increasing soil salinity caused NP decrease, particularly in the hottest days. Transpiration and gs trends vs ECe were very similar to NP. WUE, deriving from the ratio of NP and T, increased with salinity increase according to the water stress occurred in which gs decrease leads to WUE increase, in agreement with plants needs to utilize in the best way the less available water. Applying Maas and Hoffman model to relative NP vs ECe it was observed that the cv. Orlando for this parameter at leaf scale is moderately salt tolerant (threshold = 4.91 dS m(-1); slope = 4.26% m dS(-1); ECe50 = 16.65 dS m(-1)) according to the rate of tolerance in terms of heads yield reported in literature. On the same cultivar in terms of heads weight yield there was reported a lower threshold (2.6 dS m(-1)), higher slope (5.5% m dS(-1)) and lower ECe50 (11.8 dS m(-1)) that in the whole resulted in lower tolerance.