The information in this profile may be out-of-date. It was last revised in 1996. EXTOXNET no longer updates this information, but it may be useful as a reference or resource.

Please visit the National Pesticide Information Center (NPIC) to find updated pesticide fact sheets. If you don't find a fact sheet related to your question, feel free to call 1-800-858-7378. NPIC is open five days a week from 8:00am to 12:00pm Pacific Time.


Extension Toxicology Network

Pesticide Information Profiles

A Pesticide Information Project of Cooperative Extension Offices of Cornell University, Oregon State University, the University of Idaho, and the University of California at Davis and the Institute for Environmental Toxicology, Michigan State University. Major support and funding was provided by the USDA/Extension Service/National Agricultural Pesticide Impact Assessment Program.

EXTOXNET primary files maintained and archived at Oregon State University

Revised 10/96


TRADE OR OTHER NAMES: Product names include Ally, Allie, Gropper, and Escort.

REGULATORY STATUS: Metsulfuron-methyl is classified by EPA in acute Toxicity Category III, and must bear the signal word "Caution" on commercial products (37). There are tolerances for residues of metsulfuron-methyl in or on raw commodities ranging from 0.05 ppm for sugar cane and milk, to 20.0 ppm for barley hay.

INTRODUCTION: Metsulfuron-methyl is a residual sulfonylurea compound used as a selective pre- and postemergence herbicide for broadleaf weeds and some annual grasses. It is a systemic compound with foliar and soil activity, and it works rapidly after it is taken up by the plant. Its mode of action is by inhibiting cell division in the shoots and roots of the plant, and it is biologically active at low use rates. The most common uses of metsulfuron-methyl include wheat, barley, rye, and pastures. It can be used with other foliar herbicides, and is typically applied on cereals at 0.004 - 0.007 pounds active ingredient/acre, and on non-crop areas at 0.005-0.160 pounds active ingredient/acre. It is commercially available in the form of dry flowable formulations. Because it has residual activity in soils, it is necessary to allow ample time for the chemical to break down before planting certain crops (22 months for sunflowers, flax, corn, or safflower, and 10 months before planting sorghum). It should not be used on ryegrass or on pastures containing alfalfa or clovers (38).





Physical Properties:

Exposure Guidelines:


DuPont Agricultural Products
Barley Mill Plaza
P. O. Box 80038
Wilmington, DE 19880-0402


References for the information in this PIP can be found in Reference List Number 9

DISCLAIMER: The information in this profile does not in any way replace or supersede the information on the pesticide product label/ing or other regulatory requirements. Please refer to the pesticide product label/ing.