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World wide increased desertification due to recent global changes enhances the need of irrigation, which, in turn, provokes the risk of soil salinization. Furthermore, limited fresh water resources may increasingly constrain the use of low quality irrigation water. Hence, intensified use of halotolerant crop plants will be necessary, even in Europe.

Commercial use of halophytes as fresh food is limited. Several facultative halophytic members of Aizoaceae are nowadays used as special crop plants. A rare leafy vegetable species is the common ice plant Mesembryanthemum crystallinum, a Crassulacean acid metabolism (CAM) species, which is mostly cultivated in India, California, Australia, and New Zealand. It is also known in Europe as a quickly cooked tender vegetable. With their succulent, mellow, slightly salty tasting leaves and young shoots, M. crystallinum is getting interesting as delicious cool flavored salad greens during recent years. However, it is a perishable product and thus, shelf live is short. On the other hand, CAM capacity of M. crystallinum can be largely enhanced by saline irrigation. Increased CAM potentially reduces water and carbon losses.

In this project we studied whether moderate salt treatment affects physiology, growth and yield of this rare crop plant. Furthermore, we investigated whether such treatment that enhances the irreversible C(3) to CAM shift in young leaves of this CAM species, potentially prolongs shelf live. Results showed that moderate salt treatment did not negatively influence growth, yield and sensory quality. When in CAM, leaves showed reduced transpiration water losses and CAM also reduced carbon losses during storage.