New Herbicide Technologies for Roadside Vegetation Management

Home , Dithiopyr

Patrick McCullough, Ph.D.

Associate Professor

University of Georgia indaziflam ¥ Trade Name: Esplanade Ð Cellulose synthesis inhibitor Ð Similar to isoxaben

¥ Use Ð Preemergence, 3.5 to 7 oz/acre Ð Warm-season grasses only

¥ Excellent activity on grassy and broadleaf weeds

¥ Tool for resistance management

Preemergence Herbicide Rates

3 Low Rate High Rate 2.5

./acre) 2 a.i

lbs 1.5

1 Rate ( 0.5

0 Indaziflam Dithiopyr Prodiamine Oxadiazon prodiamine indaziflam Esplanade (3.5 oz/acre) + NIS Treated 11/7/2013 in Bermudagrass

Photo: 4/24/14 Esplanade + Milestone (3.5 + 5 oz/acre) + NIS Treated 9/11/2013 in Bermudagrass

Picture: 4/17/2014 Esplanade at 2.5 oz/acre Pictures: Jan. 20, 2011

October application November application Buckhorn Plantain (1 MAT) Roundup + Milestone Roundup + Milestone + Esplanade

1 MAT Nontreated Esplanade (indaziflam) indaziflam Nontreated 27 g ai/ha 54 g ai/ha 108 g ai/ha Buckhorn Plantain Control 9 WAT (2013 + 2014)

Indaziflam at 0 g ai/ha Indaziflam at 55 g ai/ha 100 * 80

* * 60 * 40 Control (%)

0 2,4-D 2,4-D + fluroxypyr metsulfuron simazine dicamba + MCPP *Signiﬁcant at P = 0.05 Esplanade + Milestone (5 + 5 oz/acre) + NIS Treated 9/11/2013 in Bermudagrass

Picture: 4/17/2014 Bermudagrass Release 4 MAT, 2012 (Spring Timing)

100 LSD = 14

BermudagrassCover (%) 20

0 Milestone Milestone + Pastora Perspective Plateau Nontreated Esplanade Bermudagrass Release 4 MAT, 2012 (Summer Timing)

100 LSD = 12

BermudagrassCover (%) 20

0 Milestone Milestone + Pastora Perspective Plateau Nontreated Esplanade Esplanade + Milestone (3.5 + 5 oz/acre) + NIS Treated 9/18/2013 in Tall Fescue

Picture: 4/17/2014 Dinitroaniline Resistant Goosegrass Control Griffin, GA (9/19/11) 100 LSD = 32

40 Control (%) 20

0 Esplanade Ronstar Barricade (indaziflam) 3.75 oz/acre 2x 2 lb ai/acre 2x 0.65 lb ai/acre 2x

Durazone 7 DAT

¥ DuraZone Ð Indaziflam + glyphosate Ð Homeowner product

Esplanade Summary

¥ Efficacious PRE herbicide Ð Early POST herbicide Ð Excellent tank-mix partner with POST herbicides to enhance weed control Ð Resistance management

¥ Recommendations Ð Use 3.5 to 5 oz/acre with Milestone or Milestone + Accord in late fall/early winter for ryegrass control and winter weed control Derigo

¥ New herbicide from Bayer Ð Released in 2015 Ð Product available soon

¥ Contains three ALS inhibitors Ð Thiencarbazone-methyl (36.4%) Ð Foramsulfuron-sodium (24%) Ð Iodosulfuron-methyl-sodium (2.4%) Dallisgrass Control - October 21

Untreated Tribute Total 3.24 oz 8-15 & 9-26-11 24 DALT McCarty, CU Derigo for Use in Roadsides

¥ Potential new tool for roadside managers Ð MSMA replacement?

¥ Enhance competition of roadside turfgrass with weeds

¥ Growth regulation of grasses to improve visibility and safety of roadsides Photo: 7/17/13 Application: Johnsongrass Control with Derigo 6/21/13 12 WAT

Nontreated Derigo 3 oz/acre Derigo 3 oz/acre (16 WAT) Indaziflam + Derigo Applied 11/2/13

Photo: 4/24/14 Nontreated Derigo 2 oz/acre

6 WAT Treatment: June 11, 2013

Derigo 3 oz/acre Derigo 4 oz/acre Bahiagrass Seedhead Control (2013)

2 WAT 12 WAT 100

Control (%) 40

0 Derigo 1.5 Derigo 3 Derigo 4 imazapic 3 sulfometuron 1 Herbicide Rate (oz/acre) Bahiagrass Seedhead Control (2013)

2 WAT 12 WAT 100 * *

Control (%) 40

0 Derigo 1.5 Derigo 3 Derigo 4 imazapic 3 sulfometuron 1 Herbicide Rate (oz/acre) Bahiagrass Vegetation Height (12 WAT, 2013)

60 LSD = 7 50

Height (cm) 20

0 Nontreated Derigo 1.5 Derigo 3 Derigo 4 imazapic 3 sulfometuron 1 Herbicide Rate (oz/acre) Bahiagrass Seedhead Control (12 WAT, 2014)

100

40 Control(%) 20

0 Derigo 1.5 Derigo 2 Derigo 3 Derigo 4 imazapic 3 sulfometuron 53 Herbicide Rate (oz/acre) Catsear Dandelion Control (12 WAT, 2014) LSD = 30 100

40 Control (%) 20

0 Derigo 1.5 Derigo 2 Derigo 3 Derigo 4 imazapic 3 sulfometuron 1 Herbicide Rate (oz/acre) Broomsedge and Vaseygrass Broomsedge Control (12 WAT) Treatment applied 6/14/2013

NIS MSO LSD = 11 100

Control (%) 40

0 Derigo 76 Derigo 102 Derigo 127 imazapic 70 Pastora 75 MSMA 2240 Herbicide Rate (g ai/ha) Vaseygrass Control (12 WAT) Treatment applied 6/25/2013

NIS MSO LSD = 30 100

40 Control (%)

0 Derigo 76 Derigo 115 Derigo 153 imazapic 70 Pastora 75 Herbicide Rate (g ai/ha) Derigo Efficacy on Weeds Evaluated

Derigo at 3 oz/acre ¥ Good (80 to 89%) to excellent (90 to 100%) Ð Catsear dandelion, tall fescue, buckhorn plantain, and bahiagrass seedheads

¥ Fair control (70 to 79%) Ð Vaseygrass

¥ Poor control Ð Broomsedge Derigo Research at UGA (2012-2014)

¥ Strengths Ð Broadleaf weeds and fescue control for bermudagrass release in spring Ð Growth regulation of bahiagrass plus weed control Ð Suppression/control of vaseygrass

¥ Potential uses for roadsides Ð Seedhead control and vegetation suppression Ð Use in sequential programs with MSMA for vaseygrass control Derigo Summary

¥ Good herbicide for problem weed control Ð Grassy and broadleaf weeds

¥ Activity on perennial weeds and bahiagrass growth regulation

¥ Consider tank-mixtures in areas with history of ALS inhibitor use (Oust, Plateau, etc.) Piper (flumioxazin + pyroxasulfone)

¥ Formulation: Piper 76WG

Ð Chlorophyll (PPO) synthesis inhibitor + Multiple MOA

¥ Weeds Controlled

Ð Flumioxazin: PRE, POST grasses, annual BLWs

Ð Pyroxasulfone: POST grassy weeds Piper 76% WG 8 oz/a

Application: 12/9/14 Photo: 1/6/15 Piper 8 oz/a Accord XRT 18 ﬂ oz/a

Application: 12/9/14 Photo: 1/6/15 Matrix at 2 oz/acre Matrix at 2 oz/acre + flumioxazin 0.38 lb ai/acre

1 Month After Treatments Photo: 7/11/13 Application: 4/16/13

Glyphomax XRT 5.4 lb/gal SL 38 fl oz/ac Piper 76% WG 10 oz/a Prodiamine 65% WG 2.3 lb/ac flumioxazin

Trade Name: Payload Family: N-phenylphthalimide derivative

¥ Mode of action: Chlorophyll (PPO) synthesis inhibitor

¥ Weeds: Postemergence control of broadleaf and grassy weeds, short residual but some PRE activity Payload (flumioxazin) 12 oz/acre 1 Month After Treatment Smooth Crabgrass Control (189 DAA, 132 DAB) 9/12/11 100 LSD = 5

40 Control (%) 20

0 Sureguard 0.38 lb ai/acre Barricade 0.75 lb ai/acre Flumioxazin Applied to Actively Growing Tifway Bermudagrass Treated on 3/16/2012 (1 WAT)

6 oz/acre 12 oz/acre 24 oz/acre Flumioxazin at 12 oz/acre, Mar. 7, 2011 Picture: August 5, 2011 Centipedegrass Treated with Payload at 12 oz/acre in April

2 WAT 6 WAT Piper and Payload Summary

¥ PRE + POST weed control

¥ Resistance management

¥ Flumioxazin advantages Ð use near water bodies Ð Excellent tank-mix partner with POST herbicides ¥ $45/acre and there is over 700,000 acres managed by the Georgia DOT.

¥ Growth regulation costs $12/acre and is used to replace mowing operations Broomsedge (Andropogon virginicus) imazapic (Plateau)

¥ Growth regulation (75 to 200 g ai/ha) Ð ALS inhibitor herbicide Ð Reduces seedhead height, seedhead number, and vegetative growth

¥ Imazapic use in Georgia Ð Reduces mowing and saves money on maintenance Ð Improves visibility and safety of roadside turf for motorists

Differential growth regulation with imazapic MSMA

¥ Very effective on broomsedge

Ð Not used by DOT since 2000

Ð Currently has restrictions by EPA task force

¥ Highway Right of Ways:

Ð 2 applications per year

Ð Buffer restriction by water bodies Objectives

To evaluate: ¥ Efficacy of imazapic for growth regulation of broomsedge and bermudagrass

¥ ALS enzyme inhibition from imazapic in these species

¥ Imazapic use with MSMA for broomsedge control 3 WAT Broomsedge

Bermudagrass 0 17.5 35 70 140 280 560 1120 imazapic (g a.i. ha-1) nicosulfuron 98 g ai/ha 2x nicosulfuron 98 g ai/ha (2x) MSMA at 2 kg ai/ha (2x)

Pictures: June 24, 2014 (8 MAIT)

imazapic at 105 g ai/ha (2x) imazapic at 105 g ai/ha (2x) MSMA at 2 kg ai/ha (2x) Broomsedge Control 9 MAIT Pooled over years (2012 + 2013)

100 LSD = 4

40 Control(%) 20

0 imazapic nicosulfuron MSMA + MSMA + MSMA imazapic nicosulfuron Broomsedge Control 12 MAIT Pooled over years (2012 + 2013)

100 LSD = 9 80

40 Control(%) 20

0 imazapic nicosulfuron MSMA + MSMA + MSMA imazapic nicosulfuron Results and Discussion

Field Experiments ¥ Imazapic provided no control of broomsedge

¥ MSMA treatments provided good control (81%) of broomsedge at 12 MAIT, however tank-mixtures with imazapic reduced control to 45%

¥ Antagonism from imazapic was not explained by reduced absorption or translocation of 14C-MSMA in lab Recommendations

¥ Imazapic may release broomsedge on roadsides by inhibiting competitive growth of bermudagrass.

¥ MSMA is critical for controlling broomsedge and other Andropogon species in Georgia roadside turf.

¥ Recommendations under current MSMA restrictions Ð Two applications of 2 lb ai/acre in late summer/fall Ð Avoid tank-mixtures of imazapic with MSMA Resistance

Year 1 Progression of Herbicide Resistance

Year 3 Year 2

Year 4 Year 5

Alan York, NCSU

Ryegrass in Bermudagrass

R S Roundup Pro 32 oz/acre Vaseygrass

Control in roadsides:

MSMA

Imazapic (Plateau)

Derigo

Pastora (nicosulfuron + metsulfuron) sethoxydim

R S R S Nontreated imazapic 18 g ai/ha

R S R S sulfometuron 53 g ai/ha nicosulfuron 70 g ai/ha glyphosate 420 g ae/ha MSMA 2.2 kg ai/ha Annual sedge (Cyperus compressus)

Sedgehammer (halosulfuron) at 1.3 oz/acre ALS-Resistant Sedge Control with MSMA Acknowledgements

¥ Seth Williams, Bill Nutt, Henry Jordan, and Dr. Jialin Yu from UGA for technical support.

¥ Bayer for supporting this research.

¥ Georgia Department of Transportation