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WEED SCIENCE2009 Annual Research ReportJames L. Griffin, Joseph M. Boudreaux, Mariana F. Bittencourt, and Jose R. MiteSchool of Plant, Environmental, and Soil Sciences104 Sturgis HallBaton Rouge, LA 70803William B. Richardson, ChancellorDavid J. Boethel, Vice Chancellor & Director,Louisiana Agricultural Experiment Station1

TABLE OF CONTENTSIntroduction . 4Acknowledgments . 5Rainfall Data . 6Herbicides and Adjuvants Evaluated . 8Abbreviations of Weed Species . 11Miscellaneous Abbreviations . 14Sugarcane Weed Control ResearchBermudagrass Eptam at Planting Test. 17Johnsongrass Eptam at Planting Test . 20Nutsedge Control with Eptam . 23Bermudagrass Control with Eptam . 27Fallow Field Control of Johnsongrass and Nutsedge with Eptam. 29Sugarcane Tolerance to SL-160 (Flazasulfuron) . 32Layby Morningglory Control Study . 34Fallow Field Control of Bermudagrass. 36Tankmixes with Glyphosate for Nutsedge Control. . .38Soybean Weed Control ResearchFungicide/Harvest Aid Test . 40Prefix and Flexstar GT Test. 47Harvest Aid Rate Study . 51Tank-Mix Partners for Ignite 280 in Liberty Link Soybean . 56Effect of Ignite 280 /- Dual Magnum on Weed Control in Liberty Link Soybean . 59Program Approach for Weed Control in Liberty Link Soybean . 63Soybean GAT Trial . 70Roundup Ready Programs Test . 79V3-V4 Soybean Dicamba Drift Study. 88R1 Dicamba Drift Study. 912

Other ResearchJohnsongrass Control with SL-160 (Flazasulfuron) . 94Johnsongrass Resistance Field Study. 96Roundup Ready/Liberty Link Stacked Trait Test #1 . 98Roundup Ready/Dicamba Stacked Trait Test #1 . 1113

IntroductionLouisiana can be divided into several areas based on cropping systems, climatic conditions, soiltypes, and pH. These factors are important in selecting specific herbicides and rates and can directlyaffect herbicide efficacy, crop safety, and injury to rotational crops. South Louisiana has an abundanceof weed species, some not commonly found in other areas of the state. Climatic conditions are favorablefor prolific weed growth and subsequent competition with crops. Weed control programs includingmechanical cultivation, crop rotation, and herbicides are used, but herbicides serve as the foundation forweed control programs. Steady progress has been made in the development of effective herbicides withcrop safety. Research and extension personnel with the LSU AgCenter work cooperatively with agrichemical companies to evaluate new herbicides for weed control and crop tolerance as well as theireffect on rotational crops.This progress report summarizes weed research conducted in sugarcane and soybeans during the2008 growing season. Results of herbicide efficacy and crop tolerance studies are presented. Resultsare preliminary since evaluation of some of the herbicides is limited. Data presented in this reportshould not be considered as an endorsement or recommendation of any herbicide and should not bereproduced without permission. Registration by the Environmental Protection Agency is requiredbefore any herbicide can be legally used.Rainfall data for the 2008 growing season are shown in Tables 1 and 2. Herbicides andadjuvants evaluated are presented in Table 3. Selected weed areas at the Ben Hur Research Farm, theSugar Research Station, and at several off-station sites have been managed to encourage uniform weedpopulations. Weed species evaluated for control are presented in Table 4. Specific information onlocation, soil type, variety, row spacing, treatment date, sprayer type, etc. for all experiments ispresented followed by a table of experimental results. Data were summarized and statistically analyzedusing Agriculture Research Manager (ARM) by Gylling Data Management, Inc., Brookings, SouthDakota. Control and crop injury ratings for all experiments are based on a scale of 0 to 100%, where 0equals no control or crop injury and 100% equals complete control or crop injury. Injury ratings arebased on chlorosis, necrosis, and stand and height reductions. Where appropriate, crop yields wereobtained. Soybean yields are adjusted to 13% moisture. Miscellaneous abbreviations used in this reportare shown in Table 5.For additional information concerning research activities presented in this report contact JamesL. Griffin, School of Plant, Environmental, and Soil Sciences, 104 Sturgis Hall, Baton Rouge, LA70803, (225) 578-1768, or by e-mail at jgriffin@agcenter.lsu.edu. This report is also available on theLSU AgCenter web sitehttp://www.lsuagcenter.com/en/our offices/departments/SPESS/Weed Science/Weed Science Annual Reports.htm4

AcknowledgmentsThe research information presented in this report was supported by Louisiana farmers throughThe Louisiana Soybean and Grain Research and Promotion Board and The American Sugarcane League.Funding support was also obtained from the Louisiana Agricultural Experiment Station and fromnumerous agri-chemical companies.Appreciation is expressed to Pat Bollich, Resident Director of the Central Stations for providingland and equipment; and to Donnie Miller, Northeast Research Station, St. Joseph, LA; and DanielStephenson, Dean Lee Research Station, Alexandria, LA; and for their assistance in planning andconducting several of these studies. Special thanks is expressed to Joseph M. Boudreaux, ResearchAssociate, and Mariana Bittencourt and Jose Mite, Graduate Assistants. Some of the research resultspresented in this report are from studies conducted as a portion of graduate research projects. Inaddition, I appreciate the patience and assistance of the student worker Matthew Bauerle.Financial assistance to conduct portions of this research was provided by the followingcompanies.Cheminova, Inc.FMC CorporationGowan CompanyHelena Chemical CompanyMonsanto CompanyPioneer Hi-Bred InternationalSyngenta Crop ProtectionUISK BiosciencesValent USA5

Table 1. Rainfall for the 2009 growing season (March - September) at the Ben Hur ResearchFarm, Baton Rouge, 0.01-Total8.123.424.171.222.892.173.746

Table 2. Rainfall for the 2009 growing season (March - September) at the Sugar Research Station,St. Gabriel, 80.960.273.103.554.597

Table 3. Herbicides and adjuvants evaluated in soybeans, sugarcane, corn.TradenameCommonnameManufacturer2, 4-D Amine 42,4-DNufarm T&S2,4-D Ester2,4-DAatrexatrazineSyngentaAgridexcrop oil concentrateHelenaAmmonium sulfate-American Plant Food Corp.Asulox, Asulox XPasulamUPIAuthority MTZsulfentrazone metribuzinFMCBicep II Magnummetolachlor lorimuron ndiuronAgrisolutionsDistinctdifluenzopyr dicambaBASFDual II MagnummetolachlorSyngentaDuPont K4hexazinone diuronSyngentaEnvoketrifloxysulfuron – ress XPTribenuronDupontFirstRatecloransulamDow ----------Continued.8

Table 3. Continued.TradenameCommonnameManufacturerGramoxone InteonparaquatSyngentaHarmony GTthifensulfuronDupontHarness Extraacetochlor atrazineMonsantoInducenonionic surfactantHelenaKarmexdiuronDuPontKarmex XPdiuronDuPontLibertyglufosinateBayer Crop ScienceLumaxmetolachor atrazine mesotrioneSyngentaMetri olachlor l up Original MaxglyphosateMonsantoRoundup Power MaxglyphosateMonsantoRoundup Weather MaxglyphosateMonsantoSencormetribuzinBayer CropScienceSequenceglyphosate sulfuronISK BiosciencesSodium Chlorate-HelenaSpartansulfentrazoneFMCSynchrony XPchlorimuron ed.9

Table 3. Continued.TradenameCommonnameManufacturerTouchdown TotalglyphosateSyngentaTreflantrifluralinDow AgroSciencesUltra BlazeracifluorfenUnited Phosphorus Inc.V-10206-Valent USAValor SXflumioxazinValent USAVelparhexazinoneDuPontWeedmaster2,4-D dicambaNuFarmYukonhalosulfuron dicambaGowan10

Table 4. Bayer codes and scientific names of weed species evaluated.Common nameWSSAabbreviationScientific nameannual bluegrassPOAANPoa annua L.annual sedgeCYPCPCyperus compressus L.barnyardgrassECHCGEchinochloa crus-galli (L.) Beauv.bermudagrassCYNDACynodon dactylon (L.) Pers.broadleaf signalgrassBRAPPBrachiaria platyphylla (Griseb.) Nashbuttercup speciesRANSSRanunculus speciescarpetweedMOLVEMollugo verticillata L.Carolina geraniumGERCAGeranium carolinianum L.common purslanePOROLPortulacca oleracea L.curly dockRUMCRRumex crispus L.cutleaf eveningprimroseOEOLAOenothera laciniata Hillcutleaf groundcherryPHYANPhysalis angulata L.entireleaf morninggloryIPOHGIpomoea hederacea var. integriuscula Grayfall panicumPANDIPanicum dichotomiflorum Michx.foxtailSETSPSetaria speciesgoosegrassELEINEluecine indicagroundcherryPHYSSPhysalis specieshenbitLAMAMLamium amplexicaule L.hemp sesbaniaSEBEXSesbania exaltata (Raf.) Rybd. ex A. W. Hillhophornbeam copperleafACCOSAcalypha ostryifolia RiddellitchgrassROOEXRottboellia cochinchinensis (Lour.) Claytonivyleaf morninggloryIPOHEIpomoea hederacea (L.) Jacq.johnsongrassSORHASorghum halepense (L.) Pers.large crabgrassDIGSADigitaria sanguinalis (L.) Scop.Continued.11

Table 4. Continued.Common nameWSSAabbreviationScientific namelittle barleyHORPUHordeum pusillum Nuttall.medicago (clover)MEDSSMedicago speciesmorningglory speciesIPOSSIpomoea speciesmouseear chickweedCERVUCerastium vulgatum L.nutsedgeCYPSSCyperus speciespitted morninggloryIPOLAIpomoea lacunosa L.prickly sidaSIDSPSida spinosa L.purple nutsedgeCYPROCyperus rotundus L.purslane speedwellVERPGVeronica peregrina L.red morninggloryIPOCCIpomoea coccinea L.red sprangletopLEFFILeptochloa panicea (Retz.) OhwiredweedMEOCOMelochia corchorifolia L.ryegrass, ItalianLOLMULolium perenne L. ssp. Multiflorum (Lam.) Husnotshepherd’s-purseCAPBPCapsella bursa-pastoris (L.) MedicussicklepodCASOBSenna obtusifolia L.smallflower bittercressCARPACardamine parviflora L.smallflower morninggloryIAQTAJacquemontia tamnifolia (L.) Griseb.smellmelonCUMMDCucumis melo L. var. dudaim Naud.spiny sowthistleSONASSonchus asper (L.) Hillspotted burcloverMEDABMedicago arabica (L.) Huds.spotted spurgeEPHMAChamaesyce maculata (L.) Smallspreading dayflowerCOMDICommelina diffusa Burm. f.velvetleafABUTHAbutilion theophrasti Medik.Continued.12

Table 4. Continued.Common nameWSSAabbreviationScientific nameVirginia pepperweedLEPVILepidium virginicum L.white cloverTRFRETrifolium repens L.wild poinsettiaEPHHLEuphorbia heterophylla L.yellow nutsedgeCYPESCyperus esculentus L.13

Table 5. Miscellaneous abbreviations used in the weed control studies.ai/AActive ingredient per acreAmtAmountASAqueous solutionAPAfter plantingBdcstBroadcast applicationbu/ABushels per acreB/LBroadleaf speciesCECCation Exchange CapacityCO2bkpkCO2-pressurized backpack sprayercolCollarcotCotyledonCVCoefficient of variationDAPDays after plantingDATDays after treatmentDBPDays before plantingDFDry flowableDGDispersible granuleECEmulsifiable concentrateFFlowablefbFollowed byFFFlat fan nozzleFmFormulationGGranularGPAGallons per acregr coverGround coverGrow stgGrowth stagehtHeightht/collrHeight to top visible collarht/lleafHeight to tip of longest leafht:nodeHeight to node ratioin/colInches to last visible collarin/lftpInches to tip of longest leaflbsPoundsContinued.14

Table 5. Continued.lb/APounds of product per acrelb ae/APounds of acid equivalent per acrelb ai/APounds active ingredient per acre on broadcast basislb/buPounds per bushellfLeafLLiquidLSDLeast significant differenceMEMicro-encapsulated# nozNumber of nozzelsN/ANot applicableNAWFNodes above white flowerOMOrganic matteroz/AOunces product per acrep. cloudyPartly cloudyPDIRPostemergence directedplntPlantpopltnPopulationPOST (x)Postemergence overtop application (first, second, etc.)PPBDPreplant burndownPPIPreplant soil incorporatedpr/AProduct per acrePREPreemergence surface applicationpsiPounds per square inch pressurerepReplicationSCSoluble ractor compressed airTRSTheoretical recoverable sugarV (x)Refers to soybean growth stage e.g. V4 vegetative with3 fully expanded trifoliate leavesContinued.15

Table 5. Continued.Trt NoTreatment numberv/vVolume/volume basisvinViningWAEWeeks after emergenceWATWeeks after treatmentWBPWeeks before plantingWGWater dispersible granuleWPWettable powderwt/pWeight per plantwt/stWeight per stemw/wWeight/weight basis% emerg.Percent panicle emergence16