Contribution for the selection of mediterranean indigenous forbs as a new ornamental crop

Abstract

In Portugal, as well as in all the nearby mediterranean countries, there are no nurseries to produce indigenous forbs to be used in ornamental wildflower meadows. The selection of mediterranean indigenous forbs, suitable for this ornamental use, is the main issue of the presented research project conducted in the University of Évora since 2006. It aimed at allowing the development of a new ornamental crop with low water demanding plants. In zones with a Mediterranean climate, the amount and timing of rainfall is often the limiting factor in choosing the species, the best choice being those preferring dry land to meadowland. The reintroduction of native plants reduces the cost of establishing and maintaining and increases the sustainability of urban green spaces. As a result of a previous research project, nine forbs were chosen to be tested in five different pre-treatment for seed dormancy break (witness, pre-chilling at 8ºC for seven days; pre-heating at 35 ºC for five days; 0,2% KNO3 solution; boiling water). The nine species are: Anchusa azurea, Cichorium intybus, Chrysantemum coronarium, Echium plantagineo, Hypericum perforatum (Hp), Lupinus angustifolium, Papaver rhoeas, Scabiosa atropurpurea (Sa), Tolpis barbata (Tb). They were chosen by their ornamental potential and different blooming seasons. The tests were made using the rules defined by the International Seed Testing Association. Seeds were harvested one year before, in natural grassland in the Alentejo region of Portugal, namely in Évora and Portalegre districts. The results revealed significative effect of species and interaction species x pre-treatment, but not effect of pre-treatment. The three species – Hp, Sa, Tb – had over than 70% germination. The other species had below 30% germination. In the case of Hp the percentage of germination increased progressively in time achieving the maximum four weeks after the beginning of the tests. This species better treatment was pre-heating, having 100% germination. In the case of Sa and Tb the germination percentage was almost maximum one week after the beginning of tests and there were not main differences between the different treatments. Although the best results were obtained for Sa in the KNO3 treatment and for Tb in the pre-chilling treatment.