Weed Management Update Larry Binning and Tim Trower University of Wisconsin Joe Bollman UWEX- Columbia County
Topics• New Herbicides• Label changes• Synthetic Auxin herbicides for soybeans- where are we now?• Resistance update• Dandelion control
New Herbicides What’s Up?• No new Modes of Action on the horizon – Last new MOA were the HPPD’s in the 1990’s: • Callisto, Laudis, Impact – Companies are still screening but introducing new herbicides are complicated by: • Stringent environmental laws • Costs – Heavy effort in seed trait technology • Using existing herbicides
New Herbicides What’s Up?• Long story short: We need to protect our current herbicide portfolio from resistance! (No silver bullet on the horizon)
Realm Q DuPont• Premix containing rimsulfuron, mesotrione and the safener isoxadifen – Two MOA’s: ALS and HPPD inhibitors• Formulated as a WDG• Application rate of 4 oz/a will provide: – 1.2 oz/a of rimsulfuron – 2.5 oz/a of mesotrione (equivalent to 2.5 fl oz/a of Callisto)
Realm Q DuPont• Apply postemergence: – After corn emerges but before corn reaches 20” or 7 leaf collars• Adjuvants are required unless tank mixed with a fully-loaded glyphosate formulation• Can be used alone, in a sequential program or tank mixed with glyphosate and many other herbicides – Third MOA for resistance management• Registration is pending
Results- Arlington Rate Percent Control YieldTreatment (rate/a) Timing G. foxtail C. lambs Velvet Dandelion (bu/a)Realm Q + 4 oz Post 100 100 100 88 203 COC+AMS 1% + 2 lbCinch ATZ fb 1 qt Pre 100 100 100 93 213 Realm Q + 4 oz Post COC+AMS 1% + 2 lbRealm Q + 4 oz Post 100 99 100 95 213 Abundit 32 fl oz+ AMS 2 lbRealm Q + 4 oz Post 100 100 100 95 219 atrazine + 0.5 lb COC+AMS 1% + 2 lbNontreated 0 0 0 0 151Preemergence treatment applied May 4.Total post treatments applied on June 1.Sequential post treatment applied June 13.
Authority XL FMC• Premix containing sulfentrazone and chlorimuron ethyl – Two MOA’s: PPO and ALS inhibitors• Formulated as a DG• Soil applied only – Application rates are dependent on soil texture and pH – 4 oz/a provides 0.155 lb ai Authority and 0.02 lb ai of Classic (medium soil rate)
Authority XL FMC• Use as part of a planed sequential program in RR or LL soybeans – Can not use full rates in Wisconsin• Will provide good early-season control of most broadleaf weeds and grasses• Soil pH will influence crop rotation interval, check the label before using! – pH less than 6.8: corn- 10 months – pH greater than 6.8: corn- 18 months• Registered
Results- Arlington Rate Percent Control YieldTreatment (product/a) G. foxtail C. lambs Velvet R. pigweed C. ragweed (bu/a)Authority Broadleaf 4 oz 75 100 90 100 100 46Authority First 4 oz 64 93 100 98 100 45Authority Assist 4 fl oz 84 100 95 100 100 46Nontreated 0 0 0 0 0 16All products applied preemergenceRates represent the set-up rate for each productEvaluated prior to glyphosate application
Warrant Monsanto• Formally know as MON63410• Encapsulated acetochlor• Labeled for postemergence use in soybeans and field corn – Do not use on sweet corn – Does not contain the safener; do not use prior to crop emergence – Corn- up to 30 inches – Soybeans- up to R-2
Warrant Monsanto• Do not apply with liquid fertilizer as a carrier• Will not control emerged weeds: – Can be tank mixed with glyphosate on RR corn and soybeans only• Will provide residual control of most annual grasses and control/suppression of some annual broadleaves• Registered
TripleFLEX Monsanto• Premix of acetochlor, flumetsulam and clopyralid – Three MOA’s: cell division, ALS and synthetic auxin• Labeled for use on herbicide tolerant field and silage corn• A rate of 1.5 pt/a provides: – 0.88 pt/a Surpass, 2.3 fl oz Stinger and 0.45 oz Python – Same ratios as SureStart
TripleFLEX Monsanto• Can be used ppi, pre or postemergence• Can be tank mixed with glyphosate – Use a RR hybrid if using postemergence• TripleFLEX is one component of resistance management• Registered
Callisto Xtra Syngenta• Premix of mesotrione and atrazine – Two MOA’s: HPPD and photosystem II• For postemergence use on corn (field, seed, sweet, silage and yellow popcorn) – Up to 12 inches in height• A rate of 20 fl oz will provide: – 2.5 fl oz Callisto and 0.5 lb atrazine
Callisto Xtra Syngenta• Restrictions: – Do not tank mix with certain EC grass herbicides – Do not apply to crop treated with Counter or Lorsban – Do not tank mix with OP or carbamate insecticides – Do not use liquid fertilizers as the carrier• Will control most annual broadleaves and many small grasses – Many tank mix options including glyphosate on RR corn – Registered
Fierce Valent• Premix of pyroxasulfone (KIH-485) and Valor – Two MOA’s: PPO and seedling shoot inhibitor• Formulated as a 76% WDG containing 33.5% Valor and 42.5% pyroxasulfone• Rate is soil dependant – Medium soil rate of 3.75 oz/a contains: • 2.5 oz Valor and 1.88 oz pyroxasulfone• Preemergence in soybeans
Fierce Valent• Seven days pre-plant in no-till or reduced till field corn• Pyroxasulfone has provided very good annual grass control and crop safety in trials at the Arlington station – Evaluated since 2006• Component of a planned sequential weed control program• Registration expected mid-to-late 2011
Results- Arlington Rate Percent Control YieldTreatment (product/a) G. foxtail C. lambs Velvet C. ragweed (bu/a)Valor 2 oz 81 100 98 94 60Fierce 3 oz 98 99 100 100 61Fierce 3.75 oz 99 99 100 100 62Nontreated 0 0 0 0 33All products applied preemergenceEvaluated prior to glyphosate application
Other Updates• Integrity (BASF) is now Verdict – Soybean has been added to the label • 5 oz/a: Outlook at 4 fl oz and Sharpen at 1 fl oz – Corn use rate has expanded • Coarse: 10-12 fl oz • Medium: 13-15 fl oz • Fine: 16-18 fl oz – Burndown applications: • Always add glyphosate • Use MSO and AMS or 28% UAN
Other Updates• Impact (AMVAC) – Increase maximum rate to 1 fl oz/a in a single or sequential application – Added fall panicum, yellow foxtail and woolly cupgrass as controlled IF applied prior to grasses exceeding 3 leaves. – Crop rotation restrictions: • wheat, barley, oats and rye- 3 months • alfalfa, potato, soybean and sunflower- 9 months • all other crops- 18 months
Other Updates• Impact (cont.) – Dry beans and snap beans can be rotated at 9 months when using 0.5 fl oz/a• Basis (DuPont) – Soybean rotation has been reduced to 15 days if using the 0.33 oz/a rate – Remains 10 months for rates greater than 0.33 oz/a
Synthetic Auxin Herbicides “Back in the Saddle Again”• DHT from Dow – Dow AgroSciences Herbicide Tolerance Trait• Provides tolerance to post applied 2,4-D – Glufosinate tolerance in soybeans and “fop” grass herbicide tolerance in corn• Developing technologies to mitigate off-target concerns and decrease potential for off-target movement• Commercial launch: – Corn: 2013 – Soybeans: 2014
Synthetic Auxin Herbicides “Back in the Saddle Again”• Dicamba tolerant soybeans from Monsanto• Provides tolerance to post applied dicamba• Working in partnership with BASF to develop technology to reduce off-target movement• Commercial launch unknown – Earliest expected is 2015 BUT
Synthetic Auxin Herbicides “Back in the Saddle Again”• Dicamba tolerant soybeans will not be tolerant to 2,4-D applications and visa-versa• Technology brings another tool to combat resistance but will require vigorous stewardship• Phenoxy off-target movement is on the EPA’s radar screen………………..
Resistance to Glyphosate in Wisconsin• No confirmed resistance of giant ragweed, common lambsquarters, or waterhemp• Variability in control has been observed at reduced rates• Seed from two susceptible giant ragweed populations (Rock & Grant Co.) are being evaluated for resistance
Resistance to HPPDs• Callisto, Impact and Laudis – Newest mode of action (MOA) on market• Latest MOA with confirmed resistance in U.S.• Waterhemp-Iowa, Illinois
Herbicide Resistance Weeds of the Midwest Wisconsin Iowa Illinois Minnesota Giant Foxtail ACCase, ALS PSII, ACCase - ALS Lambsquarters PSII PSII PSII PSII C. Ragweed - - ALS ALS G. Ragweed - ALS, Gly ALS Gly Waterhemp ALS ALS, PSII, HPPD, ALS, PSII, HPPD, Gly PPO, Gly PPO, Gly Velvetleaf PSII - - PSII ACCase---Select, Poast, Fusion ALS---Harmony GT, FirstRate PSII---atrazine, Sencor PPO---Reflex, Valor HPPD---Callisto, Impact, Laudis Gly---RoundupOnce a population becomes resistant to a MOA, it is always resistant!
Dandelions “What was old is new again”• Increasing problem in many cropping systems• Reduced tillage and less phenoxy herbicide use may be a contributing factor• Glyphosate controls seedlings but is less effective on mature plants• We have conducted several studies over the past three years on the most effective treatments• Research is continuing on herbicides and timings
Dandelion ControlFall applied and evaluated the following spring 2,4-D @ 32 fl oz + Nontreated PowerMax @ 21 fl ozSynchrony @ 0.375 oz/a + 2,4-D @ 16 fl oz + Enlite @ 2.8 oz/a + PowerMax @ 21 fl oz PowerMax @ 21 fl oz
TABLE 1: Control of dandelions with common fall and spring burndown applications Percent Dandelion Controla Treatmentb Rate Fall Applied Spring Applied Plant-back restrictions (unit/A) Evaluation Timing corn soybeans Early Late Early Octe Octe Mayc Mayd June (days) 2,4-D LVE + 16 fl oz +82 42 3 72 40 7 14 Roundup PowerMax 21 fl oz 2,4-D LVE + 32 fl oz + 76 44 15 Not applied 14 14 Roundup Original 24 fl oz Distinct + 2 oz + 73 57 48 Not applied 14 30 Roundup Original + 21 fl oz + 2,4-D LVE 16 fl oz Valor + 2 oz + 82 39 20 Not applied 30 14 Roundup PowerMax 21 fl oz + 2,4-D LVE 16 fl oz Canopy EX + 1.1 oz + 95 87 93 70 53 9 months 14 2,4-D LVE 16 fl oz Autumn + 0.3 oz 91 75 48 Not applied 30 90 Roundup PowerMax 21 fl oz Synchrony + 0.375 oz 90 40 28 81 66 9 months 14 Roundup PowerMax + 21 fl oz 2,4-D LVE 16 fl oz Enlite + 2.8 oz + 91 43 5 86 71 9 months 0 Roundup PowerMax 21 fl oz Express + 0.25 oz + 93 65 51 Not applied 14 14 Roundup PowerMax + 21 fl oz + 2,4-D LVE 16 fl oz a -Data average from 2009 and 2010 results at Arlington, WIb - Recommended adjuvants were added to all treatmentsc - Coincides with corn plantingd - Coincides with soybean plantinge - Data from 2010 only; All plots received a broadcast treatment of glyphosate in June. Typical whengrowing glyphosate resistant crops.
Summary• While fall applications of 2,4-D and glyphosate can provide good control by the time that corn is planted, control quickly drops by the end of May when soybeans are planted. In 2010 control from fall applications was essentially zero by the following fall even after an in-crop glyphosate application. This suggests that addition measures need to be taken to reduce weed populations.• Delaying applications of glyphosate and 2,4-D into spring can provide some decent suppression for 1-2 months as table 1 shows, but dandelions recovered by mid season and perennial plants are often not killed. This can result in an increase in old plants which will be more difficult to control.• Application of residual herbicides can extend control into mid- summer, and sometimes even for one year. We observed Canopy EX, Enlite, and Synchrony all provided good suppression of seedling and perennial dandelions through mid-summer unlike other treatments.