Manipulation of Perennial Ryegrass with the Plant Growth Regulator Mefluidide

In an attempt to increase the nutritive quality of herbage, the plant growth regulator mefluidide was applied at low rates (0.15-0.30 kg ai/ha) to pure stands of perennial ryegrass (Lolium perenne L.) in early spring. There was a reduction in total dry matter production of 35.8% at 0.3 kg ai/ha, but because reproductive development was significantly reduced there was a useful increase in the green leaf harvest component from 1.3% to 41.6% of total dry matter. High yields of green leaf were maintained for 100 days, in contrast to untreated swards which were composed largely of stem plus inflorescence and dead material by late spring. Mefluidide increased i11 vitro digestibility in perennial ryegrass. Mefluidide can enhance the quality of pastures for specialised uses.