Paraquat has been found to be an effective ‘fire fighting’ treatment for large glyphosate resistant Palmer amaranth, sometimes called a ‘superweed’. Researchers at the University of Georgia, USA, have found that applying paraquat through weed wipers and similar implements can very effectively kill Palmer amaranth plants up to 5ft (1.50 m) tall1. While paraquat is very effective on smaller weeds, glyphosate’s systemic action generally makes it a better option on large weeds. However, where there are glyphosate resistant weeds an innovative approach is needed. Paraquat has been approved for application through weed wipers to control weeds in peanuts in Florida, Georgia, and in North and South Carolina.
Since 2005, Palmer amaranth (Amaranthus palmeri, also known as Palmer pigweed) has become an increasing problem for farmers in Georgia and neighboring states2,3. It has become common for gangs of laborers to be used to remove weeds with hoes and machetes often at a cost of over $100 per acre ($250/ha).
Benefits of using paraquat through weed wipers
Prevents spread of glyphosate resistant weeds
More effective application of late fungicides
Much cheaper than hand-weeding
Weed wipers have been developed to apply glyphosate to tall weeds standing above crop canopies.