Lamiaceae is one of the largest families of aromatic plants and it is characterized by the presence of external glandular structures which produce essential oils highly valued in cosmetics and medicine. Plants of Lavandula latifolia, Mentha piperita, Salvia sclarea, Salvia lavandulifolia, Thymus capitatus, and Thymus mastichina were grown for one year. In order to evaluate the effects of drought stress, plants were subjected to two water treatments (100% ETo and 70% ETo, including the rainfall during the experimental period). At the end of the experiment, the biomass, the essential oil content, and leaf nutrients concentration were assessed for each water treatment and species studied. At the end of the experiment, L. latifolia, M. piperita and T. capitatus plants showed a significant fresh weight reduction under drought stress conditions whereas the other species studied remained unchanged. With respect to dry weight, only L. latifolia plants showed a reduction under water deficit conditions. As far as essential oil content was concerned, L. latifolia and S. sclarea plants had a reduction under water deficit conditions. Leaf nutrient concentration showed different trends between species considering the nutrient assessed. The economic viability of the growth of this species will be dependent on the benefits achieved which are related to yield production obtained and the price accorded for both raw material and the essential oil extracted.

The scarcity of water in the Mediterranean area has frequently led to the use of saline water in order to irrigate ornamental plants in many nurseries. However, before the large-scale use of such waters, the ways in which the plants deal with the salinity need to be evaluated. Plants of Aloe vera L. Burm, Kalanchoe blossfeldiana Poelln and Gazania splendens Lem sp. were grown in pots with a mixture of sphagnum peatmoss and Perlite. In order to evaluate the effects of different levels of salinity, three treatments using different NaCl concentrations (Electrical conductivity = 2.0 (control), 4.5 and 7.5 dS m −1) were applied over a period of 60 days. At the end of the experiment, the growth, physiological parameters and mineral content of the roots and leaves were assessed for each salinity treatment. After 60 days of exposure to salinity, the total biomass of all species decreased similarly. The mineral composition of roots and leaves was clearly affected. Osmolytes, such as proline, played an important role in the osmotic adjustment in all species increasing in the roots and leaves at the higher EC i. Different mechanisms of the salt tolerance were triggered in each species. A vera plants showed Na + accumulation at the root level and a decrease in succulence index of leaves. K. blossfeldiana plants shed leaves to release Na + and G. splendens plants accumulated Cl − and Na + at the root level, secreted salt from leaves, lost salt by shedding of old leaves and increased the succulence index of remaining leaves. We concluded that the use of saline waters is feasible for growing these ornamental plants, and G. splendens seems to be particularly well adapted to salinity, a consideration that is particularly relevant in arid saline areas.

Abstract:The blending of drainage with water of low electrical conductivity and the sequential reuse of the drainage water are innovative technologies to manage salts in agricultural drainage. Plants of Cucumis melo were grown in coir grow bags, and Rosmarinus officinalis and Cacti spp. were grown in pots with a mixture of sphagnum peat-moss and perlite. In order to assess the effect and evolution over time of these water treatments on plant growth and water management and removal of nutrients, three water treatments were applied over a period of eight weeks. These were: (1) standard nutrient solution; (2) blended water treatment (drainage water blended with water of low electrical conductivity (EC)) and (3) sequential reuse of drainage water treatment. During the experimental growing period, samples of water supplies and drainages generated in each water treatment were collected weekly and from these data water volume and nutrient loads were calculated. At the end of the experiment, leaf fresh weight of rosemary plants decreased under the fertigation with the blended and sequential reuse water treatments. Nevertheless, the application of blended and sequentially reused water allowed for the saving of significant amounts of water and nutrients in comparison to the standard nutrient solution treatment. Considering these advantages, we strongly recommend the setting-up of these water treatments in areas with water scarcity such as in the Mediterranean Basin.

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Plants of Ruscus aculeatus, known as "butcher's broom", Maytenus senegalensis, known as "confetti tree", and Juncus acutus, known as "spiny rush" were grown in pots with a mixture of sphagnum peat-moss and Perlite in order to determine the effect and evolution over time of three water use systems on plant growth, water saving and nutrient uptake. These were an open system (irrigated with standard nutrient solution) and two closed systems (blended-water (drainage water blended with water of low electrical conductivity (EC)) and sequential reuse of drainage (sequential-reuse) water), over a period of 8 weeks. Irrigation with blended-and sequential-reuse-water increased the biomass of all three species at the end of the experiment, compared to the open system. Overall, sequential-reuse-water treatment maximised biomass production. The application of blendedand sequential-reuse-water allowed savings of 17% of water in comparison to the open system. Regarding Cl, NO 3 − and H 2 PO 4 − loads, there was a removal of 5%, 32% and 32%; respectively in the blended-water treatment and 15%, 17% and 17% in the sequential-reuse water treatment compared to the open system. For the cation loads (Na + , K + , Ca 2+ and Mg 2+ ) in these water treatments there was a removal of 10%, 32%, 7% and 18% respectively in the blended-water treatment, and 17%, 22%, 17% and 18% respectively in the sequential-reuse treatment, compared to the open system.