Weed Control

WeedsCompetitionSpaceLightNutrientWaterPhysical DamageMorninggloriesHoneyvine Milkweed

Tolerance to CompetitionWeed free for 6 weeksTobacco canopy tolerates late competitionWeedy for 4 weeksWeed Control after weedy problem No competition

CultivationShallow (1 inch deep)Reduces root damageDoesnt disturb herbicide placementShears of weeds Breaking crust

CultivationDeep CultivationDamages rootsBrings up untreated soilMisconception? Brings up moisture during a drought

Rolling CultivatorsShallow CultivationScrapes surfaceHills plantsFaster Speed

Ideal HerbicideControls WeedsBroadleafGrassesNo Crop InjuryNon-persistent to cover crop or rotational cropNo drift or run-offSafe for applicator

Prowl 3.3ECWeed Spectrum

Good ControlAnnual grassesMany Broadleaf weedsPigweed

Poor ControlRhizome Johnson GrassHairy GalinsogaCommon RagweedCockleburSuppressionMorningglories

ApplicationRates 2 to 3.6 pts/AIncorporation 1 to 2 inchesPhotosensitivityPossible sun breakdownSuppresses germinating weed seedsMost in upper 2 inchesCrop safetyPlant roots below treated areas

Activity & Mode of ActionRoot & shoot inhibitorSymptomsRoot pruning StuntingMitotic poisonNot taken up by plants

Symptoms

Symptoms

Symptoms Phosphorus Deficiency

PersistenceCan cause cover crop damage especially in dry seasons

Command 3 MEWeed SpectrumGood ControlAnnual GrassesMost Broadleaf Weeds includingCommon RagweedHairy GalinsogaVelvetleaf

Command 3 MEPoor ControlPigweedsSeedling & rhizome Johnsongrass

ApplicationRates 2 to 2.67 pts/APlacement Surface application Cover crop safetyDriftPost-transplantWithin 7 days after transplanting

Activity & Mode of ActionPhotosynthesis inhibitorDamages ChlorophyllTurns plant white

PersistenceCover crop damage

Spartan DFWeed SpectrumGood ControlMost Broadleaf Weeds IncludingMorninggloriesYellow Nutsedge

Spartan DFFair ControlAnnual grassesPoor ControlCommon Ragweed Seedling & rhizome Johnsongrass

ApplicationRates (8 fl oz/A) (10.1 fl oz/A)If Morningglories or nutsedge are major weed problems

Placement Best not incorporatedDue to crop safetyOK to scratch out tractor track

Activity & Mode of ActionPhotosensitizes Plants actively take-upExposure to sunlight causes membrane disruptionSusceptible plants turn necrotic and die

PersistenceSeason long controlGrass cover crops are less sensitive

Devrinol 50DFWeed SpectrumGood ControlAnnual grasses Fair to Poor ControlMost Broadleaf WeedsCrop SafetyGood

ApplicationRate (2 lb/A)Usually in combination with Tillam for improved broadleaf controlPost-transplant OKbut pre-emergence to weeds

Activity & Mode of activityRoot growth inhibitorPersistence12 month - can cause cover crop injury especially when applied post-transplant

Tillam 6EWeed SpectrumGood ControlAnnual grasses NutsedgeFair to Poor ControlMany Broadleaf WeedsCrop SafetyGoodDamage possible under specific conditions

ApplicationRate (2.67 qt/A)Usually in combination with Devrinol for improved broadleaf control

Activity & Mode of ActivityTaken up by plants and translocated to shootsHas effect on meristemactic tissue

Persistence3 to 6 weeks Highly volatileReadily leached by in soil Can reverse leach after rainfall

Weed Control in Burley TobaccoFayette Co. David Tucker Farm

Poast 1.53EWeed SpectrumGood ControlAnnual & perennial grasses No ControlBroadleaf WeedsApplicationRate 1.5 pts/A Crop oil concentrate (1 qt/A)Post-emergence

Activity & mode of activityTaken up by plants and translocated throughoutSlow actingPersistenceNone

Diagnosing Chemical Damage in TobaccoLook for symptomStuntingLeaf distortionAbnormal vein patternsDiscolorationLook for possible sources of chemical exposureDriftOther crops near byRight of waysContaminated SprayerContaminated Water SupplyContaminated Fertilizer or Spreader Equipment

TriazinesChemicalsAtrazineSimazineSymptomsDead tissue between secondary veinsGreen or yellow tissue adjacent to vein

Triazine Test< 0.05 ppm No damage0.05 - 0.20 Injury possible depending on climatic conditions> 0.20 Injury expected

Run-offContaminated SprayerCorn SprayerBack SiphonContaminated Fertilizer BuggyUse of same buggies used for corn

Crop Exposure

Growth Regulators2,4-D, etc.Damage only to developing leaves at time of driftCan assess date of exposureBanvelSimilar to 2,4-DBut damage more persistentTordonExtreme sensitivity in tobacco .3 ppbWater SolublePersistent in soil

Growth Regulator Symptoms

Accent/BeaconForm Johnsongrass control in cornDrifts for a considerable distanceYellowingLeaf tipSpotsCauses restricted Vein (stem) growthLamina puckers

Accent/Beacon - Symptoms

Callisto

Unknown

Sheep Dip

Skunk Damage