INTRODUCTION ABG IN CBG WINTER KILL PHOTO ABG MANAGEMENT STRATEGIES 1/10/2014 POA ANNUA: LOVE IT, HATE IT, MANAGE IT DISEASE PHOTO

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1 PO NNU: LOVE IT, HTE IT, MNGE IT John E. Kaminski Penn State University INTRODUCTION nnual Bluegrass (Poa annua L.; BG) Commonly Found on Golf Courses Generally Considered an Undesirable Species (Vargas and Turgeon, 4) Poor Heat and Drought Tolerance Prolific Seedhead Producer Highly Susceptible to Various Pathogens Poor Summer and Winter Hardiness BG IN CBG DISESE PHOTO WINTER KILL PHOTO BG MNGEMENT STRTEGIES Cultural Cultivation Practices and Timing Fertility Nitrogen (Vargas and Turgeon, 4; Danneberger, 1993) Phosphorus (Raley et al., ) Iron (Carrow et al., 199; Xu and Mancino, 1) Chemical Plant Growth Regulators (Bigelow et al., 7; Nylan et al., 1997; Haley et al., 199; McCullough et al., ) Herbicides Pre and Postemergent 1

2 Soil Disturbing Cultivation BG Emergence: Hollow Core Cultivation Timing ggressive Vertical Mowing Seedlings / sq ft / rating 3 University of Maryland Golf Course Monthly Mean Temp ( o F) Monthly precipitation (inches) 4 Mean Temperature ( o F) 4 2 Total precipitation (inches) ug Sep Oct Nov Dec Jan Feb Mar pr May Month GERMINTION SUMMRY With dequate Rainfall (1999 1) Germination Begins in September (T Soil <7 o F) Germination Peaks and Decreases Dramatically By Mid October 9% Germination By Late November Early December With Low Soil Moisture/Rainfall (2) Peak Germination Delayed One to Several Weeks No Spring Flush (MD, G, C) BG MNGEMENT: FERTILITY Nitrogen Creeping bentgrass (grostis stolonifera L.; CBG) Generally Has Lower N Requirements (Vargas and Turgeon, 4) Spoon Feeding During Summer Encourages CBG Lower ph Favors Growth of CBG Over BG (Danneberger, 1993; Vargas and Turgeon, 4) Lower ph Increases vailable Micronutrients BG MNGEMENT: FERTILITY Phosphorous BG Populations Correlated With P Levels (Raley et al., ) Putting Greens Often Have dequate P Levels, But pplications May Still Occur Limitations May Be Present in Sand Based Rootzones BG MNGEMENT: IRON Fe in Turf Enhanced Color (Carrow et al., 199; Christians, 199, Minner and Butler, 194) Lower Fe Rates May Inhibit Growth of BG Than CBG (Xu and Mancino, 1) 2

3 PLNT GROWTH REGULTORS Used on Golf Courses For Variety of Purposes Seedhead Suppression Reduction in Growth Disease Suppression Common Growth Regulators Trinexapac ethyl () Flurprimidol () Paclobutrazol (Trimmit) PLNT GROWTH REGULTORS Trinexapac ethyl Not Effective for Suppressing BG (Bigelow et al., 7; Nylan et al., 1997) Flurprimidol (FL) and Paclobutrazol (PB) Can Effectively Reduce Populations (Haley et al.,199; McCullough et al.,; ) Requires Repeated pplications May Discolor Desirable Turfgrass Species PRE NDPOST HERBICIDES PHOTOS OFLOGN EXMPLES Limited Use on Golf Course Putting Greens Soil Residual Following Fall pplications May be Detrimental Often Result in Discoloration to Desirable Species Effective Herbicides May Kill Too Quickly EMERGING BG MNGEMENT PHILOSOPHY PHOTOS OFLOGN EXMPLES Low Seasonal N Rates (24 to 49 kg N/ha) High Ferrous Sulfate Rates (~49 kg/ha) Repeated Use of Type B PGRs (/Trimmit) Minimal Disturbance cidification Theory Routine Topdressing Low Mowing Heights 3

4 MTERILS ND METHODS Valentine Turfgrass Research Facility L 93 CBG/BG (7%/%) Evaluated ll Combinations N x Fe x PGR (2 x 3 x 3) Typical Experimental Design RCBD, 4 Reps, 1. x 3. m Plots pplied in 4 L/ha MTERILS ND METHODS Nitrogen (mmonium Sulfate) Rates 24 (low) or 1 (high) kg N/ha nnually Ferrous Sulfate,., and 1 lb Fe/ ft 2 Every 3 Weeks, 12, and 49 kg Fe/ha Every 3 Weeks Plant Growth Regulators Maxx (label rates) MEC (label rates) Non Treated Control MTERILS ND METHODS PO NNU POPULTION Treatments pplied May Through October, 11 ~Every 3 Weeks Limited Soil Disruption No Hollow Tine Cultivation Solid Tine Venting Routine Topdressing Mowing Heights 2. to 3.2 mm No Supplemental Nutrients 3 intersections / plot 4

5 NITROGEN RTES PLNT GROWTH REGULTORS B 1 B C 2.2 lb N/M (High). lb N/M (Low) None Percent Poa annua (%) Poa annua Populations 24 kg N/ha/Year 144 kg N/ha/Year TE None TE None FL FL Ferrous sulfate (kg Fe/ha/3 Weeks) 11 PLNT GROWTH REGULTORS B None 11 NITROGEN X IRON 4 VISUL PPERNCE 1 DT B B BC CD D DT lb Fe/M. lb Fe/M 1 lb Fe/M lb Fe/M. lb Fe/M 1 lb Fe/M High High High Low Low Low

6 11 Quality (19 ug) 24 kg N/ha/Year 1 kg N/ha/Year 9 Turfgrass Quality (1 9) Ferrous sulfate (lb Fe/ft 2 /3 Weeks) 11 Quality ( Oct) 24 kg N/ha/Year 1 kg N/ha/Year 9 Turfgrass Quality (1 9) Ferrous sulfate (lb Fe/ft 2 /3 Weeks) PHOTOS OFLOGN EXMPLES CONCLUSION High Seasonal Nitrogen (1 kg/ha) Increased Poa annua Populations, Regardless of Iron Low Seasonal Nitrogen (24 kg/ha) + High Iron (49 kg Fe/ha/application) Held Poa annua Populations Constant was Essential Component in Reducing Poa annua Populations Long Term Impact? Organic Matter, Black Layer, ph, Diseases

7 CKNOWLEDGEMENTS Research Cooperators Penn State Golf Courses Merion Golf Club Valentine Research Center Thesis Committee John Kaminski David Huff Max Schlossberg Richard rteca Jeffery Borger Dr. Kaminski s lab Tim Lulis Yu Huang my Baetsen Steve Powers 7