The influence of ethofumesate on the growth and development, chlorophyll and nitrogen content of Lolium perenne L.

Pot experiments and a hand-weeded field trial were carried out to investigate the direct effect of ethofumesate on the growth and development of Lolium perenne cv. S24.
In the field trial, ethofumesate was applied in autumn as Nortron 20% ec formulation in a volume of 2001 ha^-1 at rates of 0, 1 or 2 kg a.i. ha^-1. Treatments had no direct effect on yield in the following summer. In both the field trial and pot experiments there was initial growth suppression in the form of a reduction in shoot dry weight, lamina dry weight, tiller number per plant and plant height. However, ethofumesate increased the chlorophyll and nitrogen contents of L. perenne laminae, but only when available soil nitrogen was not limited.
It is concluded that ethofumesate can increase the yield of L. perenne by suppressing weed competition, but there is no evidence of the herbicide directly increasing the growth or yield of cv. S24.