Transcript Document
Exploring Herbicides Used to Control Invasive Weeds Commonly Used Herbicides Rangeland & Non-crop 2,4-D - Many Trade Names Auxin-like, systemic, selective • Ester, amine, and acid formulations Short residual in soil • average half-life 10 days Broadleaf herbicide • many annual broadleaf weeds notably weak on kochia • often tank-mixed High volatility Dicamba - Vanquish/Clarity/Overdrive Auxin-like, systemic, selective Relatively short soil residual • < 14 days good conditions metabolism • low to medium leaching potential, weakly adsorbed Broadleaf herbicide • many annuals, biennials, perennials thistles and knapweeds weak on toadflaxes & Russian knapweed Don’t use near water or trees/shrubs • buffalograss sensitive to injury Picloram Tordon 22K, Grazon P+D Auxin-like, systemic, selective • Restricted use herbicide Residual herbicide • average half-life 90 days • high leach potential, weakly adsorbed Broadleaf herbicide • thistles, knapweeds, leafy spurge, houndstongue, toadflaxes, bindweed, locoweed, larkspur, lupines … Grazon P+D is picloram + 2,4-D • very weak kochia & some mustards Don’t use near water, trees/shrubs • smoothbrome sensitive to injury Clopyralid Stinger, Transline, Curtail Auxin-like, systemic, selective Short residual • average half-life 40 days • moderate leaching, weakly adsorbed Broadleaf herbicide - odd spectrum • thistles, knapweeds, hawkweeds, oxeye daisy, dandelion, locoweeds … Above weeds, only control after emergence Don’t use around water • Safe around trees/shrubs Aminopyralid Milestone, Milestone VM, Forefront R&P Auxin-like, systemic, selective Short residual • average half-life 34.5 days in North America • Lab studies show potential movement; limited movement in field Broadleaf herbicide - odd spectrum • thistles, knapweeds, hawkweeds, oxeye daisy, dandelion, absinth wormwood … Forefront R&P is aminopyralid + 2,4-D Can spray to water’s edge • Half-life in water 0.6 days • Safe around some trees/shrubs Metsulfuron Escort/Ally/Cimarron Amino acid biosynthesis inhibitor • systemic, selective Moderate residual • typical half-life 30 days persistence increases with soil pH Broadleaf herbicide • perennial mustards, biennial thistles, arrowgrass, locoweed, halogeton, houndstongue, camelthorn, African rue … Combined with Milestone = Capstone o Excellent on Russian knapweed + whitetop infestations (whitetop timing) • weak on toadflaxes, Canada thistle, diffuse knapweed • must use a surfactant!! Chlorsulfuron - Telar Amino acid biosynthesis inhibitor • systemic, selective Residual • average half-life 40 days persistence increases with soil pH Broadleaf herbicide • perennial mustards, Russian knapweed, Canada thistle RK, CT high rates and fall best • must use surfactant!! • Fall applications more injurious to some grass species Imazapic - Plateau Amino acid biosynthesis inhibitor • systemic, selective Residual • most “imis” persistent e.g. imazapyr 1-4 months Broadleaf and grass • leafy spurge, bindweed, houndstongue, cheatgrass, foxtail barley … • must use methylated seed oil!! Cool-season grass injury • fall applications for leafy spurge Glyphosate - Roundup, Campaign, Rodeo, Aquamaster Amino acid biosynthesis inhibitor • systemic, non-selective Rodeo is aquatic formulation Moderate persistence • average half-life 47 days • strongly adsorbed, no soil activity Broadleaf and grass • many annuals, biennials, perennials • Cheatgrass Glyphosate + Plateau (6 fl oz of each) o Treat late fall thru winter; weather dependent Aminocyclopyrachlor Perspective Perspective • Telar + aminocylopyrachlor • Non-crop only Amino-acid biosynthesis inhibitor + Auxinlike; systemic, selective Short to long residual • Aminocylcopyrachlor half-life range 5-164 days in North America • Lab studies show potential movement; limited movement in field Broadleaf herbicide - odd spectrum • thistles, knapweeds, leafy spurge, mustards (Telar) …