New Herbicide Technologies for Roadside Vegetation Management Patrick McCullough, Ph.D. Associate Professor University of Georgia indaziflam • Trade Name: Esplanade – Cellulose synthesis inhibitor – Similar to isoxaben • Use – Preemergence, 3.5 to 7 oz/acre – 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 (%) 20 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 80 60 40 Bermudagrass Cover(%) 20 0 Milestone Milestone + Pastora Perspective Plateau Nontreated Esplanade Bermudagrass Release 4 MAT, 2012 (Summer Timing) 100 LSD = 12 80 60 40 Bermudagrass Cover(%) 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 80 60 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 – Indaziflam + glyphosate – Homeowner product Esplanade Summary • Efficacious PRE herbicide – Early POST herbicide – Excellent tank-mix partner with POST herbicides to enhance weed control – Resistance management • Recommendations – 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 – Released in 2015 – Product available soon • Contains three ALS inhibitors – Thiencarbazone-methyl (36.4%) – Foramsulfuron-sodium (24%) – 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 – 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 80 60 Control (%) 40 20 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 * * 80 60 Control (%) 40 20 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 40 30 Height (cm) 20 10 0 Nontreated Derigo 1.5 Derigo 3 Derigo 4 imazapic 3 sulfometuron 1 Herbicide Rate (oz/acre) Bahiagrass Seedhead Control (12 WAT, 2014) 100 80 60 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 80 60 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 80 60 Control (%) 40 20 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 80 60 40 Control (%) 20 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%) – Catsear dandelion, tall fescue, buckhorn plantain, and bahiagrass seedheads • Fair control (70 to 79%) – Vaseygrass • Poor control – Broomsedge Derigo Research at UGA (2012-2014) • Strengths – Broadleaf weeds and fescue control for bermudagrass release in spring – Growth regulation of bahiagrass plus weed control – Suppression/control of vaseygrass • Potential uses for roadsides – Seedhead control and vegetation suppression – Use in sequential programs with MSMA for vaseygrass control Derigo Summary • Good herbicide for problem weed control – 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 – Chlorophyll (PPO) synthesis inhibitor + Multiple MOA • Weeds Controlled – Flumioxazin: PRE, POST grasses, annual BLWs – 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 80 60 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 – use near water bodies – 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) – ALS inhibitor herbicide – Reduces seedhead height, seedhead number, and vegetative growth • Imazapic use in Georgia – Reduces mowing and saves money on maintenance – Improves visibility and safety of roadside turf for motorists Differential growth regulation with imazapic MSMA • Very effective on broomsedge – Not used by DOT since 2000 – Currently has restrictions by EPA task force • Highway Right of Ways: – 2 applications per year – 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 80 60 40 Control (%) 20 0 imazapic nicosulfuron MSMA + MSMA + MSMA imazapic nicosulfuron Broomsedge Control 12 MAIT Pooled over years (2012 + 2013) 100 LSD = 9 80 60 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 – Two applications of 2 lb ai/acre in late summer/fall – 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 .