Browsing by Author "Winsemann Falghera, Luisa"

Alfalfa (Medicago sativa L.) has been cultivated all around the world since the ancient times. It has different cultivars having diverse characteristics that are suited for different environments and conditions. However, alfalfa is not being widely cultivated in northern latitudes, especially in the Nordic countries. In this experiment, six alfalfa cultivars from different origins, namely Alexis, Lavo, Live, Hunter River, Nexus and Rangelander were tested in four different treatments and control. The treatments simulated Finnish fall conditions, focusing on temperature and day-length. Plants were grown in controlled conditions with 12 h and 14 h day-length at 10°/5°C (day/night) and 18°/15°C (day/night) for six weeks. Control plants stayed in greenhouse conditions at 16 h day-length and 18°/14°C (day/night) until flowering. Both temperature and day-length affected plant growth and development. All cultivars flowered in the greenhouse conditions, characterized by the higher temperature and longest day-length. Cultivars Alexis, Hunter River and Rangelander developed flowers most rapidly (560 GDD), whereas Lavo, a cultivar bred for cold climates, flowered last (941 GDD). Only two cultivars, Hunter River and Alexis were able to flower at 14 h DL 18/15°C, while flower buds died at 14 h 10/5°C. Moreover, all flowers died under 12 h DL treatments both at 10/5°C and 18/15°C. The combination of short day-length and low temperature (12h DL 10/5°C) seems to delay or restrict the development to generative stage in Lavo, Nexus and Live. Cultivar Lavo seemed to have good fall dormant characteristics such as prostrate behavior, short stems, fewer internodes and a strong response to low temperature and short day-length. Although alfalfa is a long-day plant, it seems that temperature rather than day-length affected dry matter accumulation. Cultivar Lavo also responded more to low temperature conditions and started to accumulate more dry matter in roots. Global warming may increase the use of new crops such as alfalfa, in the Nordic countries. Alfalfa cultivars have interesting genetic variations that could be utilized for selecting most appropriate cultivars for growing in Finland.