USDA Weed Control Compendium

Systemic Herbicides for Weed Control
Phenoxy herbicides, dicamba, picloram, amitrole, and glyphosate

AD-BU-2281, December 1983
Published and distributed in cooperation with the Extension Service, U.S. Department of Agriculture, Washington, DC.

Authors:
Dayton L. Klingman, Weed Science Laboratory, Agricultural Research Service, U.S. Dept of Agriculture, Beltsville, MD 20705
R.W. Bovey, Agricultural Research Service, U.S. Department of Agriculture, Texas A&M University, College Station, TX 77843
E.L. Knake, Agronomy Department, University of Illinois, Urbana, 61801
A.H. Lange, San Joaquin Valley Agricultural Research and Extension Center, University of California, Parlier, CA 93648
J.A. Meade, Soils and Crops Department, Rutgers University, New Brunswick, NJ 08903
W.A. Skroach, Department of Horticultural Science, North Carolina State University, Raleigh, NC 27650
R.E. Stewart, Forest Service, U.S. Department of Agriculture, Washington, DC 20013,
D.L. Wyse, Department of Agronomy and Plant Genetics, University of Minnesota, St. Paul, MN 55108

Susceptibility Chart

Table 1 lists the effects of phenoxy and some other systemic herbicides when applied as sprays on the foliage of a number of common weeds. These comparisons are based on an application rate of:
1 pound acid equivalent per acre for 2,4-D, MCPA, mecoprop, dicamba, and picloram;
1.5 pounds per acre for 2,4-DB and glyphosate; and
4 pounds per acre for amitrole (active ingredient).

The control ratings for the herbicides are interpreted as follows:

Excellent (E)	Over 95 percent of the weed population is killed by a single treatment.
Good (G)	One treatment per year maintains 85 to 94 percent suppression of top growth, or more than 95 percent of the weed population is killed by two or three treatments.
Fair (F)	From 60 to 85 percent of the weed population is killed by a single treatment, or two or three treatments per year maintain 85 to 94 percent suppression of top growth.
Poor (P)	From 10 to 59 percent of the weed population is killed by one treatment, or two or three treatments per year maintain 60-84 percent suppression of top growth.
None N)	Little or no effect is gained from treatments.

Woody plants have been largely excluded from table 1. For response of woody plants to herbicides, see USDA AH 493, Response of Woody Plants in the Untied States to Herbicides.

Labels on each herbicide show the specific registered uses.
Follow all label directions for best results and to ensure safety.
Some general uses are discussed in this bulletin.
Table 1 lists common weed species and their responses to these herbicides.

Table 1. Susceptibility of common weeds to control by phenoxy and some other systemic herbicides.

Control¹

Plant name Type of plant 2,4-D MCPA Mecoprop 2,4-D Dicamba Picloram Amitrole Glyphosate

Alexandergrass (Brachiaria plantaginea) Annual - - - - - - - E

Alligatorweed (Alternanthera philoxeroides) Perennial P N - - - - - -

Alyssum, hoary (Beteroa incana) Perennial F F - P F E F E

     Yellow (Alyssum alyssoides) Annual F F - P F F F E

Amaranth

     Green (Amaramhus hybridus) Annual E G - P E E E E

     Palmer (A. palmeri) Annual E G - P E E E E

     Powell (A. powellii) Annual E G - P E E E E

     Sandhills (A. arenicola) Annual E G - P E E E E

     Spiny (A. spinosus) Annual E G - P E E E E

     See also Pigweed.

Ammannia, pink (Ammania teres) Annual - - - E E E - E

Amorpha, leadplant (Amorpha canescens) Perennial - - - - F - - G

Angelica, purplestem (Angelica atropurpurea) Perennial G P - F G E G E

Anoda, spurred (Anoda cristata) Annual G G - F G E E E

Arrowgrass, seaside (Triglochin maritima) Perennial F - - - G E F E

Arrowhead

     Annual (Sagittaria calycina) Annual E E - E G E F E

     Perennial (S. longiloba) Perennial F F - - - - - E

Aster

     Many-flowered (Aster ericoides) Perennial G - - - E E G G

     Slender (A. exilis) Perennial E E - G E E - -

     Smooth (A. laevis) Perennial G F - F G E E G

     Spiny (A. spinosus) Perennial N N - N - F - G

     Western (A. occidentalis) Perennial P - - N G E G G

     White heath (A. pilosus) Perennial F - - N F E G G

     Woody (Xylorrhiza parryi) Perennial P N - - P P P P

Baileya, desert (Baileya multiradiata) Perennial G - - - - - - -

Balloonvine (Cardiospermum halicacabum) Perennial G - - - - - - E

Baneberry, red (Actaea rubra) Perennial - - - - F G - G

Barley, foxtail (Hordeum jubatum) Perennial N N - N N N F G

     Little (H. pusillum) Annual N N - N N N E E

Bassia, five-hook (Bassia hyssopifolia) Annual F - - - G G F G

Beachgrass, European (Ammophila arenaria) Perennial N N - N N N F F

Beardgrass, bushy (Andropogon glomeratus) Perennial N N - N N N - -

Bedstraw

     Cleavers (Gallium aparine) Perennial P N F N G E E E

     Smooth (G. mollugo) Perennial N N - N F F - G

Beeplant, Rocky Mountain (Cleome serrulata) Annual F - - - - - - -

Beggarticks, bearded (Bidens aristosa) Biennial E E - E E E E E

     Devils (B. frondosa) Annual E E - - E E E E

     Leafbract (B. comosa) Annual E E - E E E E E

     Nodding (B. cernua) Annual E E - E E E E E

     Tall (B. vulgata) Annual E E - E E E E E

Bellflower, creeping (Campanula rapunculoides) Perennial P P - P F E F E

Bentgrass, colonial (Agrostis tenuis) Perennial N N - N N N G E

     Creeping (A. stolonifera) Perennial N N - N N N G E

     Velvet (A. canina) Perennial N N - N N N G E

Bindweed

     Field (Convolvulus arvensis) Perennial G G F F G G P G

     Hedge (C. septum) Perennial G G F F G G P G

Biscuitroot (Lomatium leptocarpum) Perennial F - - - - - - -

Bistort, American (Polygonum bistortoides) Perennial F - - N - - - -

Bittercress, hairy (Cardamine hirsute) Annual G E - E E E E E

Blackeyed susan (Rudbeckia serotina) Perennial G - - - E E E E

Bloodweed (Ambrosia aptera) Annual E - - - E E - -

Blueweed, Texas (Helianthus ciliaris) Perennial G G - F E E - G

Bouncingbet (Saponaria officinalis) Perennial P N - N G F E F

Bracken (Pteridium aquilinum) Perennial N N P N G F P G

Brome, California (Bromus carinatus) Annual N N - N - - - -

     Downy (B. tectorum) Annual N N - N N P E E

     Field (B. arvensis) Annual N N - N N N E G

     Japanese (B. japonicus) Annual N N - N N P E E

Broomsedge (Andropogon virginicus) Perennial N N - N N N F E

Broomweed (Gutierrezia dracunculoides) Annual G - - - G E F F

Broomrape (Orobanche ramosa) Annual F - - - F - - G

Buckwheat

     Tartary (Fagopyrum tataricum) Annual P E - - E E G E

     Wild (Polygonum convolvulus) Annual F P F F E E E E

Buffalobur (Solanum rostratum) Annual F P - P F G F G

Bugloss, common (Anchusa officinalis) Perennial - - - F F - - G

Bugseed (Corispermum hyssopifolium) Annual E E - E E E E E

Bullnettle (Cnidoscolus stimulosus) Perennial G F - - G G G G

Bulrush (Scirpus spp.) Perennial F F - N - - - -

¹For explanation of control ratings, see page 2: E = excellent. G = good. F = fair. P = poor, and N = none.
²Sometimes biennial.

Table 1 (continued). Susceptibility of common weeds to control by phenoxy and some other systemic herbicides.

Control¹

Plant name Type of plant 2,4-D MCPA Mecoprop 2,4-DB Dicamba Picloram Amitrole Glyphosate

Burcucumber (Sicyos angulatus) Annual P F - P P E E E

Burdock, common (Arctium minus) Biennial E E - E E E F G

     Great (A. lappa) Biennial E E - E G - G E

     Wooly (A. tomentosum) Biennial E E - E F - F E

Bur-head (Echinodorus cordifolius) Annual E E - - - - - -

Burroweed (Haplopappus tenuisectus) Perennial G - - - E E - -

Buttercup

     Bur (Ceratocephalus testiculatus) Annual P F G - F - - -

     Celery leaf (Ranunculus sceleratus) Annual F - G - - - - -

     Corn (R. arvensis) Annual G E G E F F G -

     Creeping (R. repens) Perennial G E F G G F G -

     Tall (R. acris) Perennial G E - E G G G E

Campion, bladder (Silene vulgaris) Perennial N N - N G E E E

Canarygrass, reed (Pharlaris arundinacea) Perennial N N - N N N G G

Carpetgrass (Axonopus affinis) Perennial F P - P F F E E

Carpetweed (Mollugo verticillata) Annual E - G E