Pasture tolerance and efficacy of three herbicides used against giant buttercup (Ranunculus acris subsp. acris L.)

摘要

The herbicides flumetsulam, thifensulfuron-methyl and MCPA were compared for their efficacy against giant buttercup (Ranunculus acris subsp. acn's L.) and their damage to perennial ryegrass (Lolium perenne) and white clover (Trifolium repens). The tolerance of perennial ryegrass and white clover to five rates of each herbicide was measured using swards either sown in pots or transplanted from the fields The total clover yield harvested over 5 months from newly-sown pasture was 80, 59 and 4% of the untreated control for flumetsulam, thifensulfuron-methyl and MCPA applied at label rates and 95, 40 and 30% for transplanted swards respectively. The biomass yield of giant buttercup 3 months after treatment was 1,22 and 2% of the untreated control for flumetsulam, thifensulfuron-methyl and MCPA applied at the label rate. Together these experiments suggest that flumetsulam is the most effective and least pasture-damaging of these three herbicides.