Browsing by Author "Luhtanen, Juha"

Forage crops are an important part of agriculture in worldwide since about 69 % of the agricultural area is covered with permanent meadows and pastures. In Finland forages cover up to 29 % of the agricultural area and production is based on intensive cultivation. The most cultivated species in Finland is timothy grass (Phleum pratense ssp. pratense L.). It is very frost resistant and that is why it is suited for northern growth environment. Timothy cultivars can be divided based on their genotypic origin to southern, northern and intermediate types. Cultivars differ in their growth and development habit. Along climate change extreme weather conditions become more frequent, mean temperature will rise and winters will be rainier. This research tries to find out how the different cultivars from different origins differ in their cold tolerance, growth and development speed and how vernalisation affects. Besides these it was researched if different methods for evaluating the vernalisation response in winter crops were useful methods to evaluate vernalisation response in forage grasses. Research composed two years long field trial and growth chamber trial. Vernalisation accelerated the growth and development of timothy. Based on this research the southern cultivars already had readiness for growth and development despite of the vernalisation if environmental conditions were favourable. Northern cultivars attained this readiness along the vernalisation. Vernalisation affected also to the architecture of the grasses. The number of generative tillers, that produce the inflorescence, increased due to vernalisation response. The number of vegetative tiller, not inflorescence tiller, became less due to vernalisation. The research revealed that cold tolerance was dependent on the temperature of the autumn hardening period (FH-COLD). High mean temperature during the hardening period decreased the cold tolerance. If the temperature was between 0 °C and + 5 °C cold tolerance increased. According to this research vernalisation had a clear effect on timothy growth and development for example. Northern cultivars do not necessarily need such a long vernalisation as Finnish winter is. Also methods for evaluating the vernalisation response in winter crops are partly useful in pure timothy cultivars too.