Control of Jerusalem Artichoke (Helianthus tuberosus) in Barley (Hordeum vulgare)

Field experiments were conducted over a 3-yr period to evaluate the efficacy of herbicides for the control of volunteer Jerusalem artichoke [Helianthus tuberosus (L.) # HELTU] in barley (Hordeum vulgare L.) and on summer fallow. In barley, Jerusalem artichoke was controlled with a single postemergence application of clopyralid (3,6-dichloro-2-pyridinecarboxylic acid) at 1 kg ae/ha, or at 0.5 kg/ha when combined with 2,4-D [(2,4-dichlorophenoxy)acetic acid] at 0.5 kg ae/ha. Dicamba (3,6-dichloro-2-methoxybenzoic acid) at 0.2 kg ae/ha plus 2,4-D at 0.4 kg/ha was also an effective combination. Split applications of 2,4-D at 0.4 kg/ha each were more effective than a single treatment at 0.8 kg/ha. On summer fallow, glyphosate [N-(phosphonomethyl)glycine] applied at 0.5 to 2 kg ai/ha, as a single or repeated treatment, provided only marginal control of Jerusalem artichoke during the season of treatment and, in one of three experiments, reduced regrowth in the year following treatment.