By Deborah Smith-Fiola, Independent IPM Consultant, Landscape Enterprise, LLC and Stanton Gill, Extension Specialist, IPM for Nurseries and Greenhouses University of Maryland Extension Central Maryland Research and Education Center
Glyphosate is the chemical name of world’s most widely used and best-selling herbicide. It is used in more than 130 countries on agricultural crops, orchards, nurseries, greenhouses, lawns, landscapes, rights-of-way, etc.. Over 100 million pounds are applied to U.S. farms and lawns every year, according to the EPA. In the home and garden sector, it is the second most-used pesticide, with over 5 million pounds used per year. In golf courses and turfgrass maintenance, 5- 8 million pounds of glyphosate are used each year.
One landscape maintenance industry survey1 attested that glyphosate may account for up to 90% of pesticide applications in landscape beds. Glyphosate was patented by Monsanto under the trade name ‘RoundUp’ in 1974. Glyphosate is now widely available from many manufacturers under numerous trade names after patent protection ended in 2000: RoundUp, KleenUp, Accord, Imitator, Eraser, Pronto, Rodeo, etc.. There are over 750 products containing glyphosate for sale in the U.S2 , according to the National Pesticide Information Center. Glyphosate [N-(phosphonomethyl) glycine, a.k.a. the isopropylamine salt of glyphosate] is a non-selective, post-emergent, broad-spectrum systemic herbicide.
When applied to growing plants, it is absorbed by foliage and translocated to the roots, where it blocks the production of a specific enzyme pathway needed for plant growth. Wilting and death occur within ~7-10 days. After application, glyphosate binds tightly to soil particles, becoming immobilized so it can no longer harm plants. Due to no residual soil activity, a crop can be seeded or transplanted into the soil soon after application. It is ultimately broken down in the soil by microorganisms into ammonium and carbon dioxide.