Changes in water soluble carbohydrates for perennial ryegrass in the first growth in Norway and Sweden

The objective of the paper was to determine the influence of seasonal changes in temperature and radiation on water soluble carbohydrates (WSC) in first growth of varieties of perennial ryegrass (Lolium perenne L.). This was done in small-plot field experiments with a three-cut silage system at two sites, one in Saerheim, Norway and one in Uppsala, Sweden. Perennial ryegrass varieties AberDart, which had been bred to accumulate high levels of WSC, and Fennema, which accumulates normal levels of WSC, were common to both sites. Trials were established in 2000 or 2001 and samples were taken during the two following years and every week three times before first harvest