THE INFLUENCE OF FERTILIZATION ON THE QUALITY AND BIOLOGICAL GROWTH OF LOLIUM PERENNE

Abstract

Perennial ryegrass has been the subject of breeding activity focused on intensive breeding, especially in recent decades. Breeding has focused on population improvement and obtaining synthetic cultivars that show strong increases in biomass yield. This in the conditions where the production of biomass, respectively the green mass/forage is one of the most important productive features of forage plants. The ability to increase the yield of the whole plant through reproduction reaches an optimal index of leaf area quite quickly during the growth of the forage plant support. Varieties were created and selected with short growth, greater density, persistence and resistance to cutting. Although phenotypic differences between these functional groups are evident, a genome-wide analysis of the degree of differentiation and biological pathways, or genes under selection, has not been previously reported. Productive success has been achieved in recent decades as summer and autumn dry matter yield has increased between 0.3 % and 0.9% annually over the past 40–50 years, and spring dry matter yield has remained almost unchanged. Breeders have developed forage ryegrass crops with different maturity groups, from early to late season types, adapted to a long grazing season that are being used for permanent pastures, due to growth in both summer and autumn.