Five Years of Imprelis Research at North Carolina State University. Fred Yelverton North Carolina State University

Five Years of Imprelis Research at North Carolina State University Fred Yelverton North Carolina State University

Introduction Aminocyclopyrachlor KJM44 methyl ester form (tested early) MAT28 acid form Herbicide developed by DuPont for selective weed control in turf Industrial vegetation management Range and pasture Specialty crops rice, fruit, sugarcane Row crop corn, burndown Projected release late-21

Introduction Pyrimidine carboxylic acid Synthetic auxin Absorption and translocation Systemic, phloem and xylem mobile, absorbed by roots and leaves Translocated throughout plant, accumulates in meristematic regions Foliar and residual control of perennial and annual weeds Average soil half-life: 37 13 d (turf) 8 164 d (bare dissipation)

Synthetic Auxin Translocation Shoot Meristem Root Meristem

Aminocyclopyrachlor Discovered by DuPont Crop Protection DPX -KJM44: Methyl Ester Formulation DPX -MAT28: Acid Formulation Mode of Action Pyrimidine Carboxylic Acid Synthetic Auxin Family Chemistry closely related to aminopyralid (Milestone) DPX-KJM44 Aminopyralid DPX-MAT28

Synthetic Auxin Injury

Introduction Cool-season turfgrass tolerance Bentgrass (Agrostis spp.) - Do not exceed 3 oz/a Kentucky bluegrass (Poa pratensis) Chewing/creeping red fescue (Festuca rubra) Sheep fescue (Festuca ovina) Tall fescue (Lolium arundinaceum) Perennial ryegrass (Lolium perenne)

Tolerance of tall fescue to Imprelis 1 LSD = NS LSD = NS fl oz/a % Phytotoxicity 8 6 4 2 2.9 5.7 8.6 11.4 17.1 14 28 DAT Treatments applied 27 March 26.

Tolerance of tall fescue to Imprelis with various surfactants (12 fl oz/a) 1 LSD = NS LSD = 3.6 LSD = 4.7 8 Alone MSO (1.5 pt) % Phytotoxicity 6 4 2 8 9 1 11 8 9 4 5 6 6 1 WAT 2 WAT 4 WAT X-77 (.25%) Silwet (.25%) Agridex (1%) Treatments applied 1 July 28.

Nontreated Photo taken 6-1-1

Imprelis 4.5 3 May Photo taken 6-1-1

Imprelis 6 3 May Photo taken 6-1-1

Trimec 3 May Photo taken 6-1-1

Dimension 3 May Photo taken 6-1-1

Drive 3 May Photo taken 6-1-1

Tall Fescue Tolerance Tall Fescue is tolerant to Imprelis at any stage of growth.

Introduction Warm-season turfgrass tolerance Bahiagrass (Paspalum notatum) Centipedegrass (Eremochloa ophiuroides) - do not exceed 3 oz/a Zoysiagrass (Zoysia japonica) - do not exceed 3 oz/a

Tifway Bermudagrass 11 DAT DPX-MAT28: Low DRY WET

Objective Evaluate Imprelis for postemergent control of select broadleaf weed species.

Materials and methods Field experiments initiated 26-211 Broadcast application 33 GPA Four replications 24 6 ft² plots Randomized complete block design 1.4 6.2 fl oz/a 2 SL formulation

Materials and methods (cont.) Experiments were initiated on the following species: Scientific name Common name Life cycle Distribution Diodia virginiana Virginia buttonweed warm-season perennial SE United States Kummerowia striata common lespedeza summer annual SE United States Lamium amplexicaule henbit winter annual throughout United States Plantago lanceolata buckhorn plantain perennial throughout United States Taraxacum officinale dandelion cool-season perennial throughout United States

Imprelis for dandelion control % Control 1 8 6 4 98 LSD = NS LSD = NS 1 1 1 1 1 oz/a 3 4.5 6 2 28 56 DAT Imprelis applied 18 April 27.

Imprelis for white clover control applied with LCO gun (56 DAT) 1 8 LSD = NS LSD = NS 1 1 1 1 fl oz/a 3 4.5 % Control 6 4 2 April 13 May 2 Applied Treatments applied 13 April or 2 May 29.

Imprelis for white clover control applied with LCO gun (28 DAT) 1 8 LSD = NS LSD = NS 1 1 1 1 fl oz/a 3 4.5 % Control 6 4 2 April 13 May 2 Applied Treatments applied 13 April or 2 May 29.

Nontreated Photo taken 5-1-6

Imprelis 3 fl oz/a Photo taken 5-1-6, 4 WAT

Imprelis for annual lespedeza control 1 8 LSD = 12.1 LSD = 1.6 99 1 1 99 1 1 84 oz/a 1.4 2.9 % Control 6 4 64 4.3 5.7 2 28 56 DAT Treatments applied 6 June 26 or 1 June 27.

Nontreated Photo taken 7-5-6, 4 WAT

Imprelis 2.9 fl oz/a Photo taken 7-5-6, 4 WAT

Imprelis for buckhorn plantain control 1 8 84 LSD = NS LSD = NS 98 99 96 98 1 oz/a 3 4.5 % Control 6 4 6 2 56 81 DAT Imprelis applied 25 May 27.

Imprelis for henbit control 56 DAT 1 8 LSD = 13.8 LSD = 11.2 1 1 1 fl oz/a 1.4 2.9 % Control 6 4 61 5 4.3 5.7 2 21 24 31 January March Applied Treatments applied 9 January 27 or 7 March 27.

Imprelis for henbit control 1 8 LSD = NS 1 1 1 96 Imprelis 3 oz Imprelis 4.5 oz Imprelis 6 oz Escalade 3 pt % Control 6 4 2 55 DAT Treatments applied 22 October 21. Rates are per acre.

Nontreated Photo taken 11-23-1

Imprelis 3 oz/a Photo taken 11-23-1, 4 WAT

Imprelis for corn speedwell control 64 DAIT 1 LSD = 22. 88 Imprelis 3 oz 8 68 71 73 Imprelis 4.5 oz % Control 6 4 59 Imprelis 6 oz 2 8 Feb 24 Feb 24 fb Mar 23 Feb 23 fb Apr 6 Treatments applied 23 February, 23 March, 6 April 29.

Imprelis for corn speedwell control 29 DAIT 1 LSD =. Imprelis 3 oz % Control 8 6 4 Imprelis 4.5 oz Imprelis 6 oz 2 Treatments applied 2 November 21.

Imprelis for corn speedwell control 69 DAIT 1 LSD = 27.9 95 96 98 Imprelis 3 oz 8 Imprelis 4.5 oz % Control 6 4 56 38 Imprelis 6 oz 2 Nov 2 Nov 2 fb Dec 1 Treatments applied 2 November, 1 December 21.

Imprelis for smooth crabgrass control LSD = 18.3 1 AE 1 oz AE 2 oz 81 8 Imprelis 3 oz 73 Imprelis 4.5 oz % Control 6 4 29 56 2 6 DAT Treatments applied 2 June 21. AE Acclaim Extra. Rates are per acre. DIGIS: 4 leaf 2 tiller at application.

Imprelis for smooth crabgrass control 1 8 81 LSD = 18.3 88 93 AE 1 oz IM 3 oz IM 4.5 oz AE + IM 1 + 3 oz AE + IM 1 + 4.5 oz % Control 6 4 29 56 2 6 DAT Treatments applied 2 June 21. AE Acclaim Extra. Rates are per acre. DIGIS: 4 leaf 2 tiller at application.

Imprelis for smooth crabgrass control 1 8 73 LSD = 18.3 91 89 AE 2 oz IM 3 oz IM 4.5 oz AE + IM 2 + 3 oz AE + IM 2 + 4.5 oz % Control 6 4 29 56 2 6 DAT Treatments applied 2 June 21. AE Acclaim Extra. Rates are per acre. DIGIS: 4 leaf 2 tiller at application.

Smooth Crabgrass Control with Imprelis and Escalade 1 86 89 99 4.5 oz 8 68 6 oz % Control 6 4 Escalade 3 pt LSD =21. 2 1 app 2 apps 29: Orange County. Sequential application made 4 wks after initial. Trts initiated May 25, evaluations collected Sept 9. Crabgrass was < one tiller at initiation.

Crabgrass Control with Imprelis (At fescue seeding) % Control 1 8 6 4 56 68 65 84 1 99 95 4.5 oz 6 oz 4.5 fb 4.5 oz 6 fb 6 oz Dimension Drive Trimec LSD =24. 2 21: Wake County. Trts applied May 3. Data collected 6-15-1, 43 DAIT. Sequential application made 4 wks after initial. 1-3 leaf crabgrass.

Imprelis for Florida betony control 181 DAT 1 LSD = 2.3 1 1 1 95 Imprelis 3 oz 8 Imprelis 4.5 oz % Control 6 4 Imprelis 6 oz Atrazine 1 lb 2 Treatments applied 22 October 29.

Imprelis for Japanese stiltgrass control 1 8 LSD = 7.7 81 LSD = 8.3 78 9 Imprelis 3 oz Imprelis 4.5 oz Imprelis 6 oz Trimec 4 pt % Control 6 4 56 55 59 48 6 2 28 DAT 54 DAT Treatments applied 2 May 29.

Summary Imprelis has good activity on a large number of weed species found in lawns. Controls many difficult to control weeds. Tall Fescue is tolerant at any stage of growth.

Imprelis Treated Turf - Clippings Clippings should be returned. Some desirable plants can be injured if clippings are used as mulch. This mostly applies to legumes.

Questions?

Imprelis for Virginia buttonweed control 1 8 LSD = NS 97 98 99 LSD = NS 94 91 84 fl oz/a 3 4.5 % Control 6 4 6 2 56 16 DAT Treatments applied 21 May 27.

Imprelis for Virginia buttonweed control with various adjuvants % Control 1 8 6 4 LSD = 11.4 LSD = 11.7 56 58 No adjuvant MSO NIS OSS COC 2 25 25 26 23 11 4 1 54 91 DAT Treatments applied 19 June 27. MES-1 (1.5 pt/a); X-77 and Silwet L-77 (.25% vol/vol); Agri Dex (1% vol/vol).

Conclusions Single application of Imprelis (> 2.9 fl oz/a) provided excellent control of: Virginia buttonweed annual lespedeza buckhorn plantain Dandelion White clover Imprelis (4.5 fl oz/a) provided excellent henbit control, March-applied January applications required 5.7 fl oz/a

Conclusions Inclusion of select adjuvants slightly enhanced Virginia buttonweed control with Imprelis (1.4 fl oz/a) crop oil conc. > methylated seed oil & nonionic surf. Organosilicone surfactant did not enhance Virginia buttonweed control compared to Imprelis alone

Nontreated Photo taken 11-23-1

Imprelis 3 oz/a Photo taken 11-23-1, 4 WAT

Imprelis 4.5 oz/a Photo taken 11-23-1, 4 WAT

Imprelis 6 oz/a Photo taken 11-23-1, 4 WAT

Imprelis for parsley-piert control 64 DAIT 1 LSD = 28.2 Imprelis 3 oz 8 78 74 Imprelis 4.5 oz % Control 6 4 Imprelis 6 oz 2 single 3 6 w seq app Treatments applied 23 February, 23 March 29.

Imprelis for dogfennel control 1 8 LSD = NS 1 98 1 1 Imprelis 3 oz Imprelis 4.5 oz Imprelis 6 oz Trimec 4 pt % Control 6 4 2 88 DAT Treatments applied 14 June 21.

Imprelis for annual trampweed control 1 95 95 8 LSD = NS 98 1 Imprelis 3 oz Imprelis 4.5 oz Imprelis 6 oz Confront 2 pt % Control 6 4 2 41 DAT Treatments applied 8 May29.