Factors Influencing the Yield Proportions of Plantago lanceolata L. and Taraxacum officinale Web. in Lolium perenne L. Swards

Factors Influencing the Yield Proportions of Plantago lanceolata L. and Taraxacum officinale Web. in Lolium perenne L. Swards

Diaspores of Plantago lanceolata and Taraxacum officinale respectively were sown in established Lolium perenne swards to determine the dynamics of their yield proportions during five years. The experimental factors were forb species, variety of the grass species (= early or late flowering), N-fertilization, and sward density. The amount of nitrogen fertilizer had the most important effect on yield proportions of the forb species and also on the total dry-matter (= DM) yield. The single creation of gaps in grass swards before sowing forbs had a lasting positive effect on the Plantago lanceolata and Taraxacum officinale proportions. Peak proportions of Taraxacum officinale in May were reduced when it was accompanied by the early flowering Lolium perenne variety. In contrast to Taraxacum officinale, until 1996 Plantago lanceolata had high yield proportions even when 80 kg N ha^-1 a^-1 was applied. This situation was not persistent, since the proportions of Plantago lanceolata in plots with high N amounts decreased rapidly in the following years.