Updated June 27, 2017
When we launched No-Till Farmer in 1972, paraquat was the No. 1 burndown herbicide. While it has lost much of its popularity to glyphosate, Mark Loux says it is one of those herbicides (marketed as Gramoxone by Syngenta) that could have been used much more in recent years to help control marestail and to interrupt the continuous glyphosate use cycle. The Ohio State University weed scientist says paraquat is most effective on small annual weeds.
Despite company consolidations and name changes, the same firm has handled paraquat for over five decades. But that may change to some extent with the anticipated sale of Syngenta Crop Protection to ChemChina. Adama, which is also owned by ChemChina, is selling its US. paraquat product registration and marketing rights to AMVAC Chemical. However, Syngenta retains ownership of Gramoxone in the U.S.
Along with two other crop production product lines (abamectin and chlorothalonil), this acquisition was part of a Federal Trade Commission consent with ChemChina and Syngenta. It is part of a federal government agreement in which ChemChina was required to divest these assets as a pre-condition to its proposed acquisition of Syngenta AG.
When we started this publication in 1972, Imperial Chemical Inc. (ICI) of the United Kingdom had been producing paraquat for burndown weed control in orchards, coffee plantations, around buildings and railway right of ways for 10 years. Paraquat sales in the U.S. were handled by Chevron Chemical and by Chipman Chemical in Canada.