Amicarbazone for annual bluegrass control in creeping bentgrass putting greens

Transcription

1 Amicarbazone for annual bluegrass control in creeping bentgrass putting greens T. W. Gannon, F. H. Yelverton and L. S. Warren North Carolina State University

2 Introduction Annual bluegrass is difficult to control weed in creeping bentgrass No postemergent options, limited to PGRs Annual bluegrass is highly susceptible to disease causing pathogens (Teuton et al. 2007) and disturbs ball roll

3 Introduction Amicarbazone - 70% WDG Herbicide developed by Arysta LifeScience Corp. Field corn, sugarcane Preplant, PRE, E. POST Full turf registration expected spring 2011

4 Introduction Potential uses in turf Annual bluegrass control Bentgrass greens, tees, fairways Overseeded bermudagrass LOLPE - prior to or after overseeding POATR- prior to overseeding

5 Introduction Triazolinone herbicide Photosystem II inhibitor Absorption and translocation Primarily root absorbed Field half-life: d (Senseman ed. 2007) Low - moderate volatility

6 Objective Evaluate amicarbazone 70WG for postemergent annual bluegrass control in creeping bentgrass putting greens.

7 Materials and methods Field experiments initiated 2007 or 2008 Six locations Broadcast application 304 l/ha Four replications 4.5 m² plots Randomized complete block design

8 Materials and methods Treatments applied sequentially Initiated late-march/early-april 49 g/ha applied weekly Four applications 61, 92, or 123 g/ha applied every three weeks Two or three applications Paclobutrazol 280 g/ha applied every four weeks Two applications

9 Materials and methods (cont.) Data were subject to ANOVA (P=0.05). Means were separated according to Fisher s protected LSD.

10 % Control Annual bluegrass control with amicarbazone g/ha LSD = Sept 5 Oct 16 April 2 Data collected May 21. NIS included with amicarbazone 70WG. Sept and Oct POAAN had not uniformly emerged, April seedheads had began to emerge.

11 % Control Annual bluegrass control with amicarbazone g/ha LSD = Oct fb Nov E Apr fb L Apr Data collected May 21. NIS included with amicarbazone 70WG. Oct and Nov POAAN had not uniformly emerged, April seedheads had began to emerge.

12 April 24, 2008

13 128 g/ha 261 g/ha Sept (1 WAT)

14 grams/1800 cm³ Seasonal Penncross root biomass Jan Feb Mar Apr May Jun Jul Aug Sep LSD (0.05) = Oct Nov Dec 1.07 Averaged over PGRs and Mowing Hts. Sandhills Research Station,

15 % Control Annual bluegrass control with amicarbazone g/ha 20 LSD = No. applications Data collected May 13. Treatments initiated March 31, POAAN seedheads had began to emerge. NIS included with amicarbazone 70WG. Eagle Point.

16 % Control Annual bluegrass control with amicarbazone LSD = 5.1 LSD = g/ha No. apps 20 0 May June Treatments initiated March 23, POAAN seedheads had began to emerge. NIS included with amicarbazone 70WG. Sandhills Research Station.

17 Photo taken early-june Olde Point GC 49 g/ha Mar 31, Apr 9, Apr 16, and Apr 23

18 Photo taken early-june Olde Point GC 61 g/ha Mar 31 and Apr 23

19 Photo taken early-june Olde Point GC 61 g/ha Mar 31, Apr 23, and May 13

20 Photo taken early-june 92 g/ha Mar 31 and Apr 23 Olde Point GC

21 Photo taken early-june Olde Point GC 92 g/ha Mar 31, Apr 23, and May 13

22 Photo taken early-june Olde Point GC 123 g/ha Mar 31 and Apr 23

23 Photo taken early-june Olde Point GC 123 g/ha Mar 31, Apr 23, and May 13

24 % stand reduction Creeping bentgrass injury with amicarbazone LSD = 4.8 LSD = 12.4 LSD = Castle Bay Eagle Point Sandhills Station g/ha No. apps Data collected early-may. Treatments initiated mid- to late-march, NIS included with amicarbazone 70WG. Sandhills station evaluations are phytotoxicity.

25 Conclusions Fall applications did not provide adequate annual bluegrass control T ½ of d Why reduced control with fall applications?

26 Conclusions Initiated late-march, the following provided > 78% annual bluegrass control (through May) at 2 of 3 locations: 49 g/ha 4 apps 92 g/ha 2 or 3 apps Initiated late-march, the following provided > 78% annual bluegrass control (through May) at all locations: 49 g/ha 4 apps

27 Conclusions Creeping bentgrass tolerance Excluding 123 g/ha, evaluated rates and timings did not provide objectionable bentgrass injury or stand reduction.

28 Future research Determine amount of foliar vs root absorption Determine if T ½ varies in turfgrass environments Determine response of perennial versus annual biotypes Evaluate amicarbazone in combination with paclobutrazol

29 Questions?