docrice weeds - Plant Sciences
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rice weeds - Plant Sciences
Fisher Delta Research Center CCA Days Everything you didn’t realize you wanted to know about rice weed control Jim Heiser University of Missouri-Fisher Delta Research Center Weed Science Project Outline • Herbicide Resistance • In rice • Rotational crops • Product Update • Drift Issues • Rice Weed Control Basics Resistance Issues in Rice Weed Mode of Action Group Typical Example Location Smallflower Umbrella Sedge ALS Londax, Permit California, Arkansas, Missouri? Rice Flatsedge ALS Regiment, Grasp, NewPath, Permit Arkansas Red Rice ALS Imazethapr, Imazapic Brazil ALS Londax, Grasp, Imazethapyr California, Brazil Nitriles and Others Basagran Brazil ALS Regiment, Imazethapyr Grasp Brazil, Arkansas, Mississippi Thiocarbamates Ordram, Bolero California ACCase Clincher, Ricestar HT California, Mississippi Ureas/Amides Propanil Arkansas, Mississippi Synthetic Auxins Facet Mississippi, Arkansas, Brazil Triazoles, Ureas, Isoxazolidiones Command Arkansas Amazon Sprangletop ACCase Clincher, Ricestar HT Louisiana Yellow Nutsedge ALS Permit Arkansas California Arrowhead Barnyardgrass Smallflower Umbrella Sedge VS. Charles T Bryson D. Dodds Smallflower Yellow Does NOT have tubers Tubers on roots (purple=tubers on rhizomes in chains) Gradually tapering leaves Few viable seeds Sharply pointed leaves Annual propagated by seeds Smallflower Umbrella Sedge VS. Charles T Bryson D. Dodds Smallflower Yellow Londax (1993) Permit (2009) Grasp (2005?) Difficult to control in many situations BUT… Not herbicide resistant!? Yellow Nutsedge • ALS resistance • Viable seed? • 1 oz Permit replaced by • 1 gallon Propanil • + 1.5 qt Bolero • fb 1.5 pt Basagran + oil Rice Flatsedge Similar in size to Smallflower Umbrella Sedge Smaller than yellow nutsedge “Christmas Tree” smell No tubers or rhizomes Reproduction by seeds Rice Flatsedge • 4 to 6 weeks from seed to seed • Dense populations • Short days • Usually easy to control • Small colonies of susceptible plants • Resistant populations tend to be • Dense population=very competitive • Cross resistant to other ALS • Propanil + Basagran California Arrowhead • Rectangular markings on leaves distinguish it from ducksalad • Like most aquatics, best control is healthy dense rice stand. • Basagran, Propanil still work Andy Kendig Red Rice • Generally identical • Undesirable characteristics • ALS resistance • Clearfield • Natural • Could be worse • Rotation! Amazon Sprangletop • Several similar species • Long, narrow panicle • Bearded has long, membranous ligule • Ligule similar to red sprangletop • No hairy sheath Pam Trewatha Jim Stritzke Amazon Sprangletop • Resistant to Clincher and Ricestar • Resistant to other “Grass” herbicides? • Does it matter? Junglerice • Similar to barnyardgrass • Slightly prostrate • Rooting nodes • Smooth leaves • Awnless, slightly larger seeds • Purple band on leaves Tomas Marquez/DuPont-Spain Junglerice • Populations resistant to 3 MOA’s • Propanil, Ricestar and ALS • Another population resistant to Facet Barnyardgrass • Resistant to 8 modes of action world-wide! • Rice herbicide families • Syn. Auxins • Thiocarbamates • Triazolinones • Ureas/Amides • ALS inhibitors • Dinitroanilanes • Triazines • Atrazine • Chloroacetamides • Butachlor and pretilachlor Barnyardgrass Not all Barnyardgrass is resistant to all six MOA’s listed, but… • Multiple MOA resistance documented • Propanil + Facet • Propanil + Facet + NewPath • Propanil + Facet + Command • Propanil + Facet + NewPath + Command + Clincher + Prowl? Bad Scenario • What if we lose a MOA useful in another crop? • Soybean • Lipid Synthesis Inhibitors (ACCase) • Red Rice, Barnyardgrass • Select, Poast and Clincher, Ricestar • Branched Chain Amino Acid Inhibitors (ALS) • Already have in some cases • Pursuit, Classic, Scepter and NewPath, Grasp, Permit Bad Scenario What if we lose a MOA useful in another crop? • Soybeans, Corn, Cotton • • Inhibitors of Cell Division (Chloroacetamides) • Rice elsewhere • Dual, Warrant, and Butachlor, Pretilachlor Corn • Inhibition of pigment synthesis (4-HPPD) • Callisto, Balance Flexx, Laudis and Benzobicyclon Resistance Detection • Herbicides do not create resistant plants • Naturally present • Selection • Lack of competition • Cross resistance • Multiple resistance Resistance Detection • Early detection • Limits spread • Control measures • Failures ≠ Resistance • • • • Improper rate Improper application Poor timing/size Degree of infestation • Weather • Secondary flush • Antagonism Resistance Detection • • • • • • Indicators include Good performance + Poor performance Ideal conditions = poor control Localized in field Intra-species control Field history Gradual decrease Resistance Summary “Path of Least Resistance” • Don’t overuse one option • Alternatives inferior • Overlap residuals • Different modes of action • Rotate crops • Goal = 100% control • Best fit for each crop Outline • Herbicide Resistance • In rice • Rotational crops • Product Update • Drift Issues • Rice Weed Control Basics Disclaimer Use of products and trade names does not constitute a guarantee or warranty of the products named and does not signify that these products are approved to the exclusion of comparable products. Use of trade names does not imply an endorsement by the University of Missouri or by an employee of the University of Missouri. Product Update • Obey • Clomazone + Quinclorac • Strada Pro • Orthosulfuron + Halosulfuron • Strada XT2 • Orthosulfuron + Quinclorac Benzobicyclon • GWN-10235 • New a.i. and m.o.a. • Grass, broadleaf and sedge activity • Water depth dependent Lasting Results Untreated in 2012 Treated in 2012 Treated in 2012 Untreated in 2012 Outline • Herbicide Resistance • In rice • Rotational crops • Product Update • Drift Issues • Rice Weed Control Basics Herbicide Drift on Rice What is Herbicide Drift? Movement of spray particles from intended target to other areas • Physical • Any chemical • wind, temperature, pressure • Vapor • • • • Product formulation Air temperature Difference in air/soil temp Less obvious Eric Webster, LSU Misconceptions • Spray early and spray late • Low wind = less drift • NO wind = less mixing of air • Inversions • Very low winds tend to be unpredictable • Difficult to adjust swath in swirling winds Steady 3-10 mph winds provide good mixing of air and reduce inversions How to Avoid Drift • Short answer – You can’t! (completely) • You can reduce drift by • Lowering sprayer pressure • Increase carrier volume • Using the correct tips • Make sure the nozzle is also recommended for the type of application and the chemical you are using. How to Avoid Drift • Boom design and placement • Wide pattern tips • Closely spaced nozzles • 20 inches • Drift Control Agents • Thickens • Increases droplet size • Vapor Drift • Amine vs. Low Volatility Esters • Environment Herbicide Drift on Rice • Glyphosate • NewPath and Beyond • Glufosinate Eric Webster, LSU Eric Webster, LSU Glyphosate Drift on Rice Missouri Rice Surrounded by Glyphosate Resistant Crops • Early season drift symptoms include • Total plant death • Roots dying • Drought stressed • Yellowing • Leaf rolling Dr. Nathan Buehring, MSU Glyphosate Drift on Rice • Reproductive phases • 50% yield reduction • Small black necrotic area around developing seedhead (14 DAT) • May not be noticeable until harvest • • • • Blank heads Deformed heads Beak shaped seeds Straighthead appearance • shortened flag leaf NewPath Drift on Conventional Rice Early Season Drift Symptoms Include • Yellow and/or purple tinted leaves • Newest leaf • onion rolled • dead Dr. Nathan Buehring, MSU NewPath Drift on Conventional Rice • Drift at later stages of development can cause • Heads fail to emerge • Heads rot inside plant • Stunted seed heads • Beyond drift will be similar Less destructive than glyphosate after PI stage Glufosinate Drift on Rice • Reproductive or Vegetative • Cosmetic unless severe • • • • Yellowing Speckling Lesions New leaves OK LSU AgCenter LSU AgCenter Drift Detection • Where is injury • Irregular • Uniform • One side LSU AgCenter • Symptoms • Dead • Internode length • Other vegetation • Roadsides, ditches, levees, treelines Outline • Herbicide Resistance • In rice • Rotational crops • Product Update • Drift Issues • Rice Weed Control Basics RICE WEEDS • Similar to other crops • Barnyardgrass • Hemp sesbania • Morningglory • Unique weeds • Sprangletop • Aquatics TOUGHEST RICE WEED • Red rice • Identical genus & species • Identical herbicide response/biochemistry • Herbicide tolerant rice • Clearfield, Liberty Link, Roundup Ready • Red rice and “commercial” rice are sexually compatible and can cross breed TOUGHEST RICE WEED • Red rice • Identical genus & species • Identical herbicide response/biochemistry • Herbicide tolerant rice • Clearfield, Liberty Link, Roundup Ready, ACCase • Red rice and “commercial” rice are sexually compatible and CAN CROSS BREED Why Flood • Non-flooded possible • Weed Control • More intensive • Expensive • Fertility • Limits volatilization • Water, soil and price Gene Stevens Two Basic Systems • Drill seeded • • • • Intense weed control for short period Easy Fertility Flushing Timely Flood = #1 Weed Problem • Water Seeded • Always flooded • Pegging • Aquatics Water IS an Herbicide! • Flood effectively controls weeds • ~ 85% drill seeded • ~95% water seeded • Stops germination, rarely growth • Broadleaves and Aquatics • Competition/weak stand • Worse in waterseeded Acknowledgements Fisher Delta Research Center Staff University of Missouri Extension Drift information Dr. Eric Webster Dr. Justin Hensley Bruce Schultz Contact Information Jim Heiser Fisher Delta Research Center PO Box 160 147 State Hwy T Portageville, MO 63873 (573) 379-5431 (O) (573) 999-3748 (C) www.plantsci.missouri.edu/deltaweeds
