Response of Origanum majorana and Melissa officinalis to Water Stress

Xeriscape techniques are frequently used because water resources are scarce. It is necessary to know the different species in order to use the correct application of these techniques, as well as its reaction against such stress. The objective of this test is to determine the response of the studied species to water deficit. The studied species are: Origanum majorana L y Melissa officinalis L. The water stress response was proved by the test during five years, as well as it was determined their influences on plant growth and in the production of essences. The trial/test took place in the Vega del Guadalquivir (Sevilla). It was compared the reaction of the species studied in rainfed production system with the irrigated crops (75% Eto). In both species, increasing water stress, decreased biomass and essential oil yields. The decrease was higher in Melissa than Origanum. This indicates the better Origanum adaptability to water stress conditions, being more appropriate for xeriscape and dry-land aromatical plant cultivation. Three-year results indicate two species behavior for those professionals working in similar climatic conditions to Vega del Guadalquivir.