PAT 200809

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Weed Management Update Agronomic Crops
Mark Loux Horticulture and Crop Science OSU
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(No Transcript)
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New wheat herbicides

• Huskie (Bayer)
• Bromoxynil pyrasulfotole (HPPD inhibitor)
• Controls small winter/summer annual broadleaf
  weeds
• Up to 4 to 6 leaf, or 4-inch diameter
• OSU guide - rated 8 or 9 on most broadleaf weeds
• Fall or spring, 1-leaf to flag leaf emergence
• Can be applied in 28
• Allow 4 months before planting soybean

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New wheat herbicides

• Orion (Syngenta)
• MCPA florasulam (ALS inhibitor)
• Controls small broadleaf weeds
• OSU guide - rated 9 on mustards, chickweed,
  lambsquarters, shepherdspurse, pennycress,
  smartweed, common ragweed
• seedling stage weeds
• 3-leaf to joint stage
• Apply in 28 N ?? (label does not specify)
• Allow 4 months before planting soybean

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New wheat herbicides

• Finesse (DuPont)
• Chlorsulfuron (Glean) metsulfuron (Ally)
• PRE or POST to wheat
• Apply in fall after 1-leaf stage
• Most effective control of annual bluegrass
• Reduces risk of crop rotation problems
• Fall application
• Controls annual bluegrass, winter annual
  broadleaf weeds
• Can be applied in 28
• Finesse is a long-residual herbicide
• Allow 6 months before planting STS soybean
• Allow 18 months before corn, non-STS soybean

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Wheat herbicides - winter annual grass
controlApply in late fall for most effective
control
(PRE glyphosate app often controls these grasses
also)
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Generics gone wild - wheat herbicides

• Tribenuron-methyl
• Express TotalSol 50 WDG
• 1/4 - 1/2 oz
• Nuance 75 WDG
• 1/6 - 1/3 oz
• Tribenuron-methyl thifensulfuron premix
• Harmony Extra TotalSol 50 WDG
• 0.45 - 0.9 oz
• Nimble, TNT Broadleaf 75 WDG
• 0.3 - 0.6 oz

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Generics gone wild - corn/soybean herbicides

• Nicosulfuron (corn)
• Accent, 75 DF - 2/3 oz
• NIC-IT, 2 lb/gal L - 2 fl oz
• Samson, 0.33 lb/gal L - 12 fl oz
• Accent, NIC-IT labels similar aside from product
  rate
• Samson - only on field corn, seed corn
• Samson - product contains needed adjuvants
• Thifensulfuron (soybeans)
• Harmony SG, 50 WDG - 1/8 oz
• Harass, Unity, 75 WDG - 1/12 oz

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Impact (AMVAC) - POST in corn

• Common name topramezone
• site of action HPPD inhibitor (same as
  Callisto)
• Field corn, popcorn, sweet corn, inbreds
• Apply up to 45 days before harvest
• Controls broadleaf weeds
• Suppresses/controls small grasses
• Most effective when mixed with atrazine, applied
  with MSO
• Good choice to bail out failed PRE programs in
  conventional corn

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Laudis (Bayer) - POST in corn

• Common name tembotrione
• Contains safener isoxadifen
• Site of action HPPD inhibitor (same as
  Callisto)
• Field corn, popcorn, sweet corn, inbreds
• Timing up to V7 field corn, up to V6 sweet corn
• Controls broadleaf weeds
• Can suppress/control small grasses
• Most effective when mixed with atrazine, applied
  with MSO
• Rate 3 oz/A with atrazine or glyphosate, 2 oz/A
  with Liberty

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Comparison of Callisto, Impact, LaudisPOST on 4
to 6 inch grass, 2 to 4 inch broadleafOSU - 2006

• Foxtail Broadleaf weeds
• ( control)
• Study 1 2 1 2
• Callisto atrazine 65 - 99-100 -
• Impact atrazine 100 97 91-100 100
• Laudis atrazine 82 89 99-100 100

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Comparison of Impact, Laudis OSU - 2008

• Foxtail Broadleaf weeds
• ( control)
• PRE - Dual (0.8 pt/A)
• ImpactatrazineMSO 77 79 - 99
• LaudisatrazineCOC 76 93 - 100
• No PRE
• ImpactatrazineMSO 65 62 - 100
• LaudisatrazineCOC 50 85 - 100
• LaudisatrazineMSO 47 90 - 100

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Resolve Q - POST in corn

• Rimsulfuron (Resolve) thifensulfuron (Harmony
  GT) isoxadifen
• Tank mix partner for POST glyphosate or Ignite in
  glyphosate-resistant or Liberty Link corn
• Isoxadifen safener to reduce risk of corn
  injury, broaden window of application
• Up to V6 corn or up to 20 inches
• Helps control emerged grasses, lambsquarters,
  pigweed
• Several weeks of residual control
• Apply with COC or NIS plus AMS or 28N
• No NIS needed if applied with loaded glyphosate

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Cadet (FMC) - POST in corn, soybeans

• Common name fluthiacet-methyl
• site of action PPO inhibitor
• Controls/suppresses small lambsquarters, pigweed,
  nightshade, morningglory
• Apply with NIS, COC, or MSO
• Field corn, popcorn, sweet corn, inbreds
• Corn 2-collar to 48 inches, before tassel
• Soybeans 1st trifoliate to flowering

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Envive and Valor XLTbroad-spectrum residual
soybean herbicides

• Envive (DuPont)
• Premix of chlorimuron thifensulfuron (Harmony)
  flumioxazin (Valor)
• - Fall or spring - up to 3 days after planting
• - 3 to 3.5 oz in Roundup Ready soy program
• Valor XLT (Valent)
• Premix of chlorimuron flumioxazin (Valor)
• - Fall or spring - up to 3 days after planting
• - 3 to 3.5 oz in Roundup Ready soy program
• 3 oz product provides 1.7 oz/A of Valor
• Control or suppress most broadleaf weeds
• Exception ALS-resistant giant ragweed

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Rates of chlorimuron-containing products

• Canopy DF Canopy EX Envive Valor XLT
• 2.25 oz 1.1 oz 2.5 oz 2.5 oz
• 3.0 oz 1.4 oz 3.5 oz 3.1 oz
• 4.0 oz 1.9 oz 4.7 oz 4.2 oz
• Lowest rate can be applied at any soil pH
• Higher rates only where composite soil pH is 7.0
  or less
• Valor XLT - higher rates only where pH is 6.8 or
  less

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Authority First, Sonic - PRE/PPI in
soybeans(think Gauntlet)

• Sonic (Dow AgroSciences)
• Authority First (FMC)
• Premix of sulfentrazone (Spartan) plus
  cloransulam (FirstRate)
• 3 oz rate 2.6 oz Spartan 0.3 oz FirstRate
• 3 to 4 oz in Roundup Ready soy program
• Controls/suppresses most broadleaf weeds
• No control of ALS-resistant ragweeds

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Comparision of Spartan and Valor - residual
control

• Spartan
• Controls pigweeds, waterhemp, lambsquarters,
  nightshade, smartweed, marestail
• Partial control of morningglory, velvetleaf,
  nutsedge
• Can suppress grasses
• Valor
• Controls pigweeds, waterhemp, lambsquarters,
  nightshade, marestail
• Partial control of common ragweed, velvetleaf,
  smartweed
• Can suppress grasses, morningglory

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Flumioxazin - Valor, Chateau (Valent)

• Valor labeled preplant on corn
• field corn only - 2 oz/A
• Apply 14 to 30 days before corn planting
• No-till fields only, do not till before or after
  application
• Do not mix with grass herbicides (Dual, Harness,
  Outlook, etc)
• Controls triazine-resistant lambsquarters
• Chateau labeled for established alfalfa
• Residual control of broadleaf weeds -
  lambsquarters, pigweeds, some winter annuals
• Does not control emerged weeds
• Apply when alfalfa has less than 6 inches of
  growth
• Do not harvest/graze for 25 days after
  application

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Sulfentrazone herbicides (FMC) - PRE in soybeans

• Spartan Advance
• Spartan glyphosate
• Possible antagonism of glyphosate activity
• Add 2,4-D to help counteract
• residual control of pigweeds, waterhemp, black
  nightshade, lambsquarters
• Spartan Charge
• - Spartan carfentrazone (Aim)
• Authority Assist
• Spartan imazethapyr (Pursuit)
• Controls small-seeded broadleaf weeds
• Suppresses grasses
• lambsquarters, pigweeds, smartweed, waterhemp,
  marestail, waterhemp

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PRE soybean herbicides - residual control

• Most broad-spectrum Valor XLT/Envive
• Gangster
• Sonic/Authority First
• Canopy DF, Scepter
• Canopy EX
• Authority Assist
• Valor, Spartan
• Least broad-spectrum metribuzin, Python

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PRE soybean herbicidesHow much help to
glyphosate/2,4-D burndown?

• Helps the most Canopy EX or DF
• Valor XLT/Envive
• Gangster, Sonic/Authority First
• Authority Assist, Pursuit
• Spartan, Valor, metribuzin, Python
• Helps the least Scepter

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Projected Timeline for New Weed Management
Transgenics??

• Liberty Link soybean 2009
• RR2Yield soybean 2009
• Optimum GAT soybean 2010
• Optimum GAT corn 2011
• DHT corn ??
• DHT soybean ??
• Dicamba-resistant soybean ??
• Balance-resistant soy ??
• all of these except LL soy are also
  glyphosate-resistant

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Glyphosate vs Ignite (glufosinate)

• Site of action
• Glyphosate - EPSP inhibitor
• Glufosinate - glutamine synthetase inhibitor
• Translocation in plant
• Glyphosate - yes
• Glufosinate - limited
• Spray coverage more important for glufosinate
• Rain-free period
• Glyphosate - 1 to 4 hours
• Glufosinate - 4 hours

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Glyphosate vs Ignite (glufosinate)

• Glyphosate
• annuals, biennials, perennials (needs help on
  some)
• Small to large size - adjust rate as necessary
• Affected by time of day, hard water
• More active in low spray volumes
• Standard use rate - 0.75 lb ae/A 10
• Ignite
• Most effective on small annuals, 4 to 6 inches
• Can suppress some perennials
• Affected by time of day, low humidity, low temps,
  other stresses
• 15 gpa or higher volumes, medium droplets
• Standard use rate - 22 oz/A 10

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Management of Liberty Link soybeans

• Weed-free start at planting
• Best - Preplant tillage or burndown application
  in spring
• Not as good - replacing spring burndown with fall
  herbicide app
• For fall apps, must use chlorimuron product to
  ensure control of weeds into May
• Use residual herbicides in PRE applications
• Must control lambsquarters,
• Suppress grass and broadleaf weeds to maximize
  Ignite activity
• Slow weed growth and reduce weed population

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Management of Liberty Link soybeans

• POST to small weeds
• Ignite - 22 oz AMS
• 4 to 6 inch weeds
• 15 gpa or higher, medium droplets
• Second POST as needed
• Ignite - 22 oz AMS
• Giant ragweed, late grass flushes
• Approx 3 weeks after 1st application

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Late POST glyphosate applications reduced
soybean yield!
6 yield loss
10 yield loss
Yield ( of weedfree)
Weed size at time of POST glyphosate application
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Glyphosate/ALS resistant giant ragweed
siteClarksburg, OHAfter several years of poor
control in RR soybeans
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Liberty Link soybeans - POST IgniteControl of
glyphosate/ALS resistant giant ragweed

• Giant Rag Lambsquarters
• ( control - Aug 6)
• 22 days after plant (DAP)
• Ignite POST 60 90
• Ignite POST late POST 90 100
• 4-6 in ragweed (37 DAP)
• Ignite POST 88 75
• Ignite POST late POST 100 100
• 12 in ragweed (42 DAT)
• Ignite POST 57 70
• Ignite POST late POST 100 88

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Liberty Link soybeans - POST IgniteControl of
glyphosate/ALS resistant giant ragweed

• Gi Rag Lambsq
• 6/24 8/6 6/24 8/6
• control
• Glyphosate POST late POST 20 30 100 100
• Ignite POST late POST 99 100 80 100
• PRE Valor XLT
• Ignite late POST 98 70 100 100
• Ignite POST late POST 99 100 100 100
• POST 4 inch ragweed, 37 days after planting
• Late POST 3 weeks after POST

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Liberty Link soybeans Clarksburg, OH
2 POST glyphosate applications 0.75 lb ae/A fb
same
2 POST Ignite applications 22 oz/A fb same
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OSU C.O.R.N. Newsletterhttp//corn.osu.edu/OSU
Weed Science Website http//agcrops.osu.edu/weeds/
Weed Control Guide for OH/IN OSU Extension
Bulletin 789loux.1_at_osu.edu614-292-9081