2017 Weed Control

Update

Current Weed Control Issues

Pigweed Control

Herbicide Resistant Weeds

New Weed Control Technologies

Glyphosate Resistant Palmer amaranth in Soybeans

Glyphosate Resistant Waterhemp in Eastern Kansas

Weed Management Theme for 2017

Multiple Pronged Approach

Cultural practices

Sequential herbicide programs

Residual herbicides

Multiple herbicide sites of action

Timing, Timing, Timing!

Maximum growth stage/height label guidelines for postemergence waterhemp and Palmer amaranth control.

Herbicide Rate WaterhempPalmer

Amaranth

Cobra 12.5 oz 6 lf/3 in 6 lf/3in

Ultra Blazer 1.5 pt 6 lf/4 in 6 lf/4 in

FlexStar/Reflex 1 pt 2 lf 4 lf

FlexStar GT 3.5 pt 2 in 1 in

Marvel 7.25 oz 4 in 3 in

Liberty 29 oz 5 in 4 in

Cadet 0.9 oz 2 in --

Growth of Palmer Amaranth with 5 days of Hot Weather

June 15 June 20

Successful weed managementMultiple pass systems

Fall and/or early spring burndown in no-till

Use preemergence herbicidesControls germinating seedlings

Helps control pigweeds

Avoids missing appropriate POST application timing

Use post herbicides as needed to small weeds

New Technologies for Soybeans

New HerbicidesZidua Pro

Proliferation of generics: fomesafen, aciflourfen, flumioxazin, glufosinate

New Trait TechnologiesXtend Soybeans

Enlist Soybeans

HPPD Soybeans

Zidua Pro (BASF) Premix containing 2.28 lb pyroxasulfone (Zidua, 15), 1.33 lb

imazethapyr (Pursuit, 2), and 0.48 lb saflufenacil (Sharpen, 14) per gal.

Fall, Preplant, or PRE to soybeans

Rates: 4.5 to 6 oz/a

Adjuvants: MSO and N fertilizer source for burndown activity.

Do not plant wheat for 4 Mo; corn for 8.5 Mo; Clearfield Sunflower for 9.5 Mo; alfalfa for 10 Mo; Clearfield canola for 12 Mo; or cotton, oats, sorghum or sunflower for 18 Mo after application.

New Seed Technologies in Soybeans

No new novel herbicide modes of action or active

ingredients on the near horizon

Crops stacked with multiple traits

Dicamba resistant soybeans (Xtend) from Monsanto

2,4-D resistant soybeans (Enlist) from Dow

HPPD resistant soybeans from Bayer and Syngenta

Roundup Ready 2 Xtend Soybeans Soybeans that contain a gene that confers resistance to

dicamba stacked with the Genuity Roundup Ready 2 trait

technology.

Resistant gene isolated from a soil bacteria.

Resistance is based on metabolism of dicamba by soybeans.

New dicamba formulations specifically for RR2X soybeans.

Traits and some herbicides finally approved.

XtendiMax , FeXapan and Engenia now approved for RR2X

soybeans.

Dicamba Products for Xtend Crops New low volatile formulations of dicamba have been

developed by industry, which will be the only dicambaproducts labeled on Xtend crops.

Monsanto dicamba products for Xtend soybeansXtendimax – new dicamba product with Vapor Grip Technology

Roundup Xtend – Glyphosate + dicamba premix with Vapor Grip

DuPont dicamba product for Xtend soybeans Fexapan – same formulation as Xtendimax

BASF dicamba product for Xtend soybeansEngenia – new dicamba BAPMA salt

Standard rate of dicamba will be 0.5 lb ae/a

Xtendimax, Fexapan, and Engenia Label Guidelines for use on Xtend Soybeans Rates: Xtendimax and Fexapan: 22 to 44 oz Pre, 22 oz Post

Engenia: 12.8 oz Pre or Post

Timing: preplant through R1 soybeansbefore weeds exceed 4 inches tall

Do not tank-mix with any other herbicide*

Only apply with approved adjuvants*

Only apply with TTI 11004 nozzles at a maximum of 63 psi*

Do not apply with Ammonium Sulfate

* Unless listed as approved at companion website

Xtendimax, Fexapan and Engenia e-label websites for latest updates

www.xtendimaxapplicationrequirements.com

www.fexapanapplicationrequirements.dupont.com

www.engeniatankmix.com

Xtendimax, Fexapan, and Engenia Label Guidelines for Xtend Crops

No aerial application

Minimum 10 gpa

Do not exceed 15 mph ground speed

Do not exceed boom height 24” above canopy

Do not apply during temperature inversion

Xtendimax, Fexapan, and Engenia Label Guidelines for Xtend Crops

Spray only between 3 and 15 mph

Do not spray if wind > 10mph in direction of sensitive areas

DO NOT APPLY this product when the wind is blowing toward adjacent commercially grown dicamba sensitive crops, including but not limited to, commercially grown tomatoes and other fruiting vegetables (EPA crop group 8), cucurbits (EPA crop group 9), and grapes.

Buffer zone requirements

Xtendimax Label GuidelinesPROTECTION OF SENSITIVE AREAS

Maintain a 110 foot downwind buffer (when applying 22 fluid ounces of this product per acre) or a 220

foot downwind buffer (when applying 44 fluid ounces of this product per acre) between the last treated

row and the closest downwind edge (in the direction in which the wind is blowing). If any of the

following areas below are directly adjacent to the treated field, the areas listed below can be considered

part of the buffer distance.

To maintain this required buffer zone:

• No application swath can be initiated in, or into an area that is within the applicable buffer distance.

The following areas may be included in the buffer distance calculation when adjacent to field edges:

• Roads, paved or gravel surfaces,

• Planted agricultural fields containing: corn, dicamba tolerant cotton, dicamba tolerant soybean,

sorghum, proso millet, small grains and sugarcane. If the applicator intends to include such crops as

dicamba tolerant cotton and/or dicamba tolerant soybeans in the buffer distance calculation, the

applicator must confirm the crops are in fact dicamba tolerant and not conventional cotton and/or

soybeans.

• Agricultural fields that have been prepared for planting.

• Areas covered by the footprint of a building, silo, or other man made structure with walls and or roof.

RR2X Soybean Response to Dicambaseveral hours after treatment

Weed control in Xtend soybeans, Manhattan, KS, 2016 (Peterson and Thompson).

Herbicide Rate Paam Vele

----(% control)----

Roundup Pmax+Xtendimax 32oz+22oz 85 100

Fierce/RU Pmax+Xtendimax 3oz/32oz+22oz 99 100

Auth Elite/Pmax+Xtendimax 25oz/32oz+22oz 96 99

Boundary/Pmax+Xtendimax 2pt/32oz+22oz 95 98

Rowel+Warrant/Pmax+Xmax 2+64oz/32oz+22oz 99 100

LSD (5%) 4 NS

Planted & PRE 6/1, poor Pre activation; Post treatments 6/20, Paam~10”

RR2 Xtend Soybeans

Roundup PowerMax + Dicamba (P)

RR2 Xtend Soybeans

Fierce XLT (PRE) fb Roundup PM + Dicamba (P)

Weed control in different soybean systems at Manhattan, KS, 2016 (Peterson and Thompson).

SB SB

Herbicide Trait Rate Injury Paam Vele Ilmg Yield

(%) ----(% control)---- (Bu/a)

Rowel/Roundup Pmax RR2Y 2oz/32oz 6 82 100 75 70

Warrant+Tric/RU+WUltra RR2Y 48+5oz/32+50oz 0 91 98 63 74

Rowel/RU Xtend RR2X 2oz/64oz 0 100 100 82 77

Row+XMax/RU Xtend+War RR2X 2oz+22oz/64+48oz 0 100 100 85 79

Valor/Liberty LL 2oz/29oz 0 100 100 88 80

Auth Maxx/Liberty+Zidua LL 64oz/29oz+2oz 0 100 100 96 77

Lsd (5%) 5 2 13 4

Planted and PRE 5/12, good PRE activation; Post 6/10, weeds < 2”.

Weed control in Xtend soybeans, Manhattan, KS, 2016 (Peterson and Thompson). Herbicide Rate Girw Lacg Paam

---------(% control)--------

RU Pmax+Fexapan+Envive/

PMax+Fexapan

22 oz+ 22 oz +2.5 oz/

22 oz+22 oz100 94 100

RU Pmax+Fexapan+Envive/

Pmax+Fexapan+Cinch

22 oz+22 oz +2 oz/

22 oz+22 oz+1 pt100 97 100

RU Pmax+Fexapan+Fierce/

Pmax+Fexapan

22 oz+22 oz+3.5 oz/

22 oz+22 oz100 94 100

RU Pmax+Fexapan+Fierce/

Pmax+Fexapan+Warrant

22 oz+22 oz+3.5 oz/

22 oz+22 oz+1 pt100 97 100

Lsd (5%) NS 3 NS

PP treatments applied 5/3 To 8” giant ragweed; Xtend soybeans planted 5/23; Post treatments

applied 6/13 to large crabgrass and Palmer amaranth < 4”.

RR2 Xtend Soybeans

Envive+Glyphosate+Dicamba (PP) fb Glyphosate+Dicamba (P)

RR2 Xtend Double Crop Soybeans

Roundup Xtend+Auth MTZ (PP) fb Roundup Xtend +Warrant (P)

Enlist SoybeansSoybeans that contain a 2,4-D resistant gene that is

also stacked with both glufosinate and glyphosate resistant traits.

2,4-D resistance is based on metabolism of 2,4-D by soybeans

Enlist trait deregulated by USDA and Enlist Duo approved by EPA in fall of 2014

Export approvals for China and EU pending

Enlist Soybeans2,4-D Product

New 2,4-D choline formulation that has less volatility losses than 2,4-D amine.

2,4-D choline is the only 2,4-D formulation labeled for use on Enlist soybeans.

Enlist Duo is a premix of glyphosate and 2,4-D choline and will be the only 2,4-D choline product available initially.

Standard rate of 3.5 pt/A. is equal to 0.75 lb ae glyphosate + 0.75 lb ae 2,4-D (~ 1.5 pt of 4lb 2,4-D).

Enlist Duo on Enlist Soybeans Rate: 3.5 to 4.75 pt/ac

Timing: Preplant or preemergence Postemergence from Emergence to R2 soybeansWeeds less than 6 inches tall

Do not apply more than 1 PP or PRE treatment and no more than 2 Postemergence treatments.

Recommended as part of sequential program with residual PRE herbicide program

Do not apply aerially

Enlist Duo Stewardship GuidelinesWeather restrictions

Buffer zones

Application requirements

Approved spray tips

Spray pressure limits

Enlist tank-mix and stewardship websites:http://www.enlist.com/en/tank-mix

http://www.enlist.com/en/how-it-works/enlist-ahead

Enlist Ahead App for treatment decisions

Protection of sensitive areas or state restrictions which ever is most restrictive

You must maintain a 30 foot downwind buffer (in the direction in

which the wind is blowing) from any area except:

1. Roads, paved or gravel surfaces.

2. Planted agricultural fields. (Except those crops listed in the

“Susceptible Plants” section)

3. Agricultural fields that that have been prepared for planting.

4. Areas covered by the footprint of a building, shade house,

green house, silo, feed crib, or other man made structure with

walls and or roof.

At the time of application, the wind cannot be blowing toward adjacent

commercially grown tomatoes and other fruiting vegetables (EPA crop group 8),

cucurbits (EPA crop group 9), grapes and cotton without the Enlist trait.

2,4-D and Dicamba Resistant SoybeansPotential Benefits

Improved control of hard to control weeds

Morningglory, velvetleaf, kochia, buckwheat, smartweeds, etc

Improved control of herbicide resistant weeds

Marestail, pigweeds, ragweeds, kochia

Excellent crop tolerance on resistant varieties

Expanded rate options

Improved flexibility of burndown options without preplant

interval restrictions

2,4-D and Dicamba Resistant SoybeansPotential Risks

Perception that herbicide resistant crops will solve

all weed problems

Discourage use of residual herbicides

Over reliance on new technology and development

of 2,4-D and/or dicamba resistant weeds

Further development of weeds with multiple

resistance to different herbicide MOA’s

2,4-D and Dicamba Resistant SoybeansPotential Risks

Spray drift to non-resistant varieties and crops

Spray tank contamination on subsequent

applications to non-resistant varieties and crops

Misapplication to non-resistant fields

Poor record keeping

Miscommunication with applicator

Dicamba application to Enlist Soybeans 2,4-D application to Xtend Soybeans

Xtend and Enlist Soybeans are not Cross Resistant

Rinse Effect following Dicamba

Single Rinse Double Rinse Triple Rinse

2,4-D and Dicamba Resistant SoybeansSummary

New herbicide resistant crop technologies will provide new options to help with weed control, but need to be part of an integrated weed management program that utilizes residual herbicides and different herbicide modes of action to optimize weed control and crop production, while sustaining the technology.

Stewardship will be critical to long-term success.

HPPD Soybeans Soybeans that contain a gene that conveys resistance to

certain HPPD herbicides. Varieties will be phased in over time with different stacked traits.

Balance GT Beans from Bayer – Resistance to isoxaflutole (Balance Bean herbicide) and glyphosate.

Balance GTLL Beans from Bayer – Resistance to isoxaflutole, glyphosate, and glufosinate.

MGI soybeans from Syngenta – Resistance to mesotrione(Callisto), isoxaflutole (Balance), and glufosinate (Liberty). Likely stacked with glyphosate resistance.

Metabolism based resistance.

Commercialization 2018?

Balance Bean @ 2 fl oz/A +

Sencor DF @ 5.33 oz/A

Balance Bean @ 3 fl oz/A +Dual II Mag @ 1 pt/A

FbyLiberty @ 29 oz/A

HPPD Resistant SoybeansPotential Benefits and Risks

Improved control of herbicide resistant and other hard to control weed species in soybeans.

New herbicide mode of action for soybeans.

Multiple herbicide resistant traits and herbicide options.

Increased selection pressure for HPPD resistant weeds.

Dallas Peterson

Extension Weed Specialist

Department of Agronomy

dpeterso@ksu.edu

785-532-5776

Twitter: @ksuweeddoc