Key Points
- The response of Italian ryegrass to Moddus varied depending on the season or cultivar but the maximum yield response and Margin Over Chemical Costs was achieved from the use of at least 2l/ha.
- The Moddus response of Nui perennial ryegrass in a dryland situation varies markedly in relation to the season. In both years the best yields were around 1.2l/ha but the Margin over Chemical Cost was slight for most Moddus rates in the dry year.
- The yield response of Quartet tetraploid ryegrass varied markedly from year to year. In two years there was no significant yield increase from Moddus use.
- There is an interaction between Moddus and wild oat herbicides. Application of Commando prior to the application of Moddus resulted in no increase in yield in Quartet over the nil treatment at the higher rates of Moddus. The low rates of Moddus (0.8l/ha) consistently increased yield, but further research is needed to better define the response.