The effects of mowing on the distribution of glyphosate within the canopy of perennial pepperweed (Lepidium Latifolium L.)

摘要

Perennial pepperweed is an invasive herbaceous perennial that can quickly establish and in many sensitive areas throughout the west. In these sensitive areas (e.g. wetland, riparian) few herbicides are registered for use in controlling this weed, and provide limited control when used exclusively (Renz & DiTomaso 1999). Fortunately when combined with early season mowing, glyphosate can provide excellent control given ample resprouting occurs (Renz & DiTomaso 1999). Several mechanisms can be responsible for this enhanced control including: 1) increased deposition of glyphosate onto shoots, 2) altered distribution of glyphosate to tissue that favors accumulation below ground, 3) increased absorption of the glyphosate, and 4) increased translocation rates of the glyphosate below ground. Previous results indicate translocation rates are not altered due to mowing (Renz & DiTomaso 1999), however applications are delayed to allow shoots to resprout. This delay synchronizes treatments with maximum translocation rates into below ground organs (Renz & DiTomaso 1999). Experiments in 1999 addressed how mowing altered the deposition and distribution of glyphosate within the canopy of perennial pepperweed.