Variation of biomass production and essential oil yield of Artemisia herba-alba Asso. in relation to planting density in Southern Tunisia.

In Tunisia, Artemisia herba-alba Asso. is a very common steppe species of the natural rangelands. It is also well known as an aromatic and medicinal species. In spite of its adaptation to the difficult ecological conditions (xeric soils, aridity...), the natural habitats of Artemisia in Tunisia have obviously regressed these last years due to its overuse coupled with repeated droughts. This work aims at optimizing the cultural practices of Artemisia herba-alba and estimating the essential oil yield of this species in relation to various planting densities. The results show that in addition to increasing growth due to greater resource capture, planting density affects the aboveground biomass, the vegetative re-growth and the response of plants to cutting. It also affects the chemical composition and mainly the essential oil yield.