Cultivation to Supplement Residual Herbicides in Sugarbeet

Abstract

The migration of waterhemp (Amaranthus tuberculatus) into northern sugarbeet (Beta vulgaris) growing regions has prompted sugarbeet producers to utilize inter-row cultivation in their weed management program as no currently registered herbicides can control glyphosate-resistant waterhemp postemergence. Field experiments were conducted to evaluate cultivation efficacy on waterhemp and common lambsquarters (Chenopodium album) and to evaluate cultivation safety on sugarbeet. Cultivation efficacy experiments demonstrated cultivation removes 65% of waterhemp and has no effect on further waterhemp emergence, but can be deleterious to common lambsquarters control if cultivation is timed before sugarbeet canopy closure. The ideal time to implement inter-row cultivation in sugarbeet is after sugarbeet canopy is closed and can suppress further weed emergence. Cultivation safety experiments demonstrated three cultivations as late as August 16 had no effect on sugarbeet yield and quality. Cultivation is a valuable tool to control glyphosate-resistant weeds with no deleterious effects if used correctly.