Tolerance of Tall Fescue to Sulfentrazone When Applied with Various Fertilizers and Three- Way Herbicides

Transcription

1 Tolerance of Tall Fescue to Sulfentrazone When Applied with Various Fertilizers and Three- Way Herbicides Dustin F. Lewis Fred H. Yelverton Travis W. Gannon Leon Warren

2 Outline Introduction Experimental Premise Materials and Methods Results and Discussion Conclusions Label Revisions

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4 Home lawns comprise the largest turfgrass sector in the United States Total Area of Home Lawns = Million Acres (Roberts, 1987) Average Lawn Size = ±0.5 Acres within the Transitional Climate Zone (Liskey, 2008)

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10 Lawncare Service Economics 2002 (Haydu et al., 2005) Generated $19.8 billion in total revenue Employed 295,841 full and part-time employees 53,840 registered lawncare firms in the US Ranging from 46 in Alaska to 3,643 in California

11 Who Do You Choose!?

12 Tall Fescue Festuca arundinacea Schreb.

13 Mode of Action Protoporphyrinogen oxidase (PPO) inhibition Developed by FMC Initial Registration in 1997 Labeled for control of annual grasses, sedges, and annual broadleaf weeds in residential and institutional lawns Sulfentrazone

14 Initially developed as a PRE herbicide in soybeans at 420 g ha -1 (Hancock, 1992) POST applications controlled weeds at 140 g ha -1 (Vidrine et al., 1992; Walker et al., 1994) Sulfentrazone applied in combination with surfactants increased herbicidal-activity by increasing absorption through the cuticle (Dayan et al., 1996) Sulfentrazone

15 Weed and Feed Concept Chemical and physical reactions between herbicides and liquid fertilizers can effect efficacy (Sander et al., 1987) Ammonium sulfate (21-0-0) tank-mixed with sulfentrazone improved efficacy on velvetleaf and Pennsylvania smartweed but no effect on giant foxtail (Dirks et al., 2000)

16 Objective Interaction between sulfentrazone, urea (46-0-0), and three-way herbicides on tall fescue reported to NCSU by Lawncare Operators Determine the response of tall fescue to sulfentrazone-containing herbicides when applied with liquid fertilizers and three-way herbicides

17 Materials and Method 2x3x3 Factorial RCBD w/ 4 replications CO 2 pressurized spray boom calibrated at L/ha Visual ratings (0-100% scale) 0 = No plant injury 100= Complete plant death Analysis of variance conducted using Fisher s Protected LSD at P<0.05 level

18 Treatments Herbicide Fertilizer Name Rate Type Ratio Application Method Dismiss 0.46 kg/ha -1 Urea Solo Ammonium Echelon 0.84 kg/ha-1 nitrate Triple Tank-mixed Independent 24.5 kg N/ha

19 Tall Fescue Injury 5 DAI: Dismiss = Solo Application = Tank-mixed with Fertilizer = Applied Independently LSD =

20 Dismiss Dismiss Dismiss

21 Tall Fescue Injury 5 DAI: Echelon = Solo Application = Tank-mixed with Fertilizer = Applied Independently LSD =

22 Echelon Echelon Echelon Nontreated

23 Tall Fescue Injury 14DAI: Dismiss = Solo Application = Tank-mixed with Fertilizer = Applied Independently LSD =

24 Tall Fescue Injury 14DAI: Echelon = Solo Application = Tank-mixed with Fertilizer = Applied Independently LSD =

25 Sulfentrazone + Urea + 3-Way Herbicides

26 Materials and Method Treatments chosen to mimic tankmixtures used by Lawncare Operators in tall fescue lawns Three-way herbicides combination of 2,4-D, MCPA, and dicamba Iron applications often used to reduce herbicide injury Treatments Echelon Echelon + Iron Echelon + Trimec Classic Echelon + Triplet Echelon Echelon + Trimec Classic Echelon + Triplet Echelon w/ Iron Echelon + Trimec Classic w/ Iron Echelon + Triplet w/ Iron Dismiss + Trimec Classic w/ Iron Dismiss + Triplet w/ Iron Rate 0.84 kg ai/ha 0.84 kg ai/ha 6.4 L/ha 0.84 kg ai/ha L/ha 0.84 kg ai/ha L/ha 0.84 kg ai/ha kg N/ha 0.84 kg ai/ha L/ha kg N/ha 0.84 kg ai/ha L/ha kg N/ha 0.84 kg ai/ha kg N/ha 6.4 L/ha 0.84 kg ai/ha L/ha kg N/ha 6.4 L/ha 0.84 kg ai/ha L/ha kg N/ha 6.4 L/ha 0.42 kg ai/ha L/ha kg N/ha 6.4 L/ha 0.42 kg ai/ha L/ha kg N/ha 6.4 L/ha

27 Tall Fescue Injury 3 DAI: = Herbicide(s) Alone = Herbicide(s) = Herbicide(s) Iron LSD =

28 Sulfentrazone Injury

29 Sulfentrazone + Urea

30 Sulfentrazone + Urea + Iron

31 Tall Fescue Injury 14 DAI: = Herbicide(s) Alone = Herbicide(s) = Herbicide(s) Iron LSD =

32 Conclusions Liquid fertilizers should not be applied with or shortly after applications of sulfentrazone Applying iron with sulfentrazone + liquid fertilizers can reduce injury to tall fescue Injury from sulfentrazone + urea does not reduce turfgrass cover and generally last less than two-weeks

33 Label Revisions for 2009

34 Questions?