Development, seed and biomass production of selected weeds in semi-dwarf oilseed rape hybrids

Recently semi-dwarf oilseed rape varieties appeared in practical cropping. So far, only few studies about their properties in combination with weeds are available. Recently however an increasing number of weeds that are difficult to control are observed in oilseed rape. For the experiment Anchusa arvensis (L.) M.aEuro-aEuro-Bieb., Sisymbrium officinale (L.) Scop. and a mixture of three different Geranium species were selected to study their development, seed and biomass production. Consequences for cropping on semi-dwarf oilseed rape cultivars were derived from the results. Three rape cultivars different in plant height were chosen for the experiments: the normal growing variety "Viking", the semi-dwarf variety "PR45D01" and a full dwarf rape biotype for breeding purposes. In contrast oilseed rape with normal height, infestation of light-indigently and high growing weeds is more probable in semi-dwarf oilseed rape varieties. These weeds show increased biomass production and higher seed production per plant.