Algae management can be difficult on golf course putting greens. This presentation highlights various aspects of algae including: biology, problems associated with it, research findings, and management strategies.

1. Algae Management For Golf Course Putting Greens John Kaminski1 and John inguagiato2 1Penn State University 2University of Connecticut

4. prokaryotic cyanobacteria blue-green algae

5. chlorophyll release oxygen and photosynthesize

6. phormidium & oscillatoria Tredway et al., 2006

7. likely many species involved visual & molecular identification is difficult

8. The Problem With Algae…

9. subsurface slim mats develops in or below canopy

10. mucilage production protection and h2o conservation

11. algal crusts form in thinned turf impermeable to h2o

12. scarification required promote infiltration and seedling germination

13. © LP Tredway black layer anaerobic bacteria & hydrogen sulfide gas

14. yellow spot associated with algae growth (Tredway et al., 2006)

15. yellow spot & algae many questions remain unanswered

16. Conditions promoting algae…

17. water, water, water… excessive and/or at inopportune time

18. shade or overcast skies almost guaranteed to develop algae

19. poor soils from construction or self imposed

20. poor drainage creating standing water, excessive moisture

21. weak or thinned turf mechanical stress, diseases, chemicals, etc.

22. all conditions together may or may not see algae

23. Managing algae populations Fertility | Wetting Agents | Fungicides

24. nitrogen sources applications of ammonium sulfate, urea, nitrates, others

25. algae development on a putting green following repeated fertilizer applications, UMD 2003 a a a b b b Fertilizers were applied (5-24 kg N/HA) every two weeks from June 2002 to November 2003 b b

26. 20-20-20

27. Ammonium Sulfate

28. Ammonium Sulfate a 20-20-20 a

29. algae development on a putting green following repeated fertilizer applications, UMD 2003 a a a b b b Fertilizers were applied (5-24 kg N/HA) every two weeks from June 2002 to November 2003 b b

30. impact of fertilizers on algae development on a golf course putting green, UConn 17 August 2010 a a a b

31. Impact of Fertility Summary Nitrogen Sources Ammonium Sulfate = Near Complete Suppression Others = Moderate Suppression 20-20-20 = No Reduction Impact of Phosphorous No Impact in 2009-2010 Study

32. chemical suppression fungicides, “fertilizers”, and wetting agents

33. Serendipitous Algae Findings Observed Algae Reduction in Plots Treated With: Phosphites Wetting Agents

34. Phosphate vs Phosphite Phosphate = Fertilizer Phosphoric Acid (H3PO4) Ex. K3PO4 Phosphite ≠ Fertilizer Phosphorous Acid (H3PO3) Ex. K2HPO3

35. Preventive suppression of algae on a golf course putting green, UConn 17 August 2010 a a b b bc bc bc bc H3PO4 = Phosphate H3PO3 = Phosphite Phos = Phosphite-Based FT = “Fertilizer” FG = “Fungicide” bc c c c

36. Preventive suppression of algae on a golf course putting green, UConn 17 August 2010 Untreated Daconil 3.4 fl oz 14-day

37. Preventive suppression of algae on a golf course putting green, UConn 17 August 2010 Untreated Alude 7.4 fl oz 14-day

38. Curative suppression of algae on a golf course putting green, UConn 17 August 2010 a a b cd bcd H3PO4 = Phosphate H3PO3 = Phosphite Phos = Phosphite-Based FT = “Fertilizer” FG = “Fungicide” bc cd cd bc a d cd

39. Summary of Phosphite Trials Traditional Fungicides Hard to Beat DaconilUltrex (Chlorothalonil) Protect (Mancozeb) Phosphites Suppress Algae Regardless of Intended Use (FT or FG) Preventive Better Than Curative Impact of Phosphite Rates?

40. main effect of phosphate/phosphite rates on algae suppression on a bentgrass green, uconn 2010 Treatments were applied every 14 days from 20 May to 26 August 2010.

41. main effect of phosphate/phosphite types on algae severity on a bentgrass green, uconn 2010 Treatments were applied every 14 days from 20 May to 26 August 2010. Data represent average of all titrations evaluated

42. Summary of Titration Study All Phosphites Suppressed Algae Suppression Increased with Increased Phosphite Rates “Limited” Suppression with Phosphate High Rates Caused Minor Phytotoxicity with Repeated Applications (>10.9 kg a.i./HA)

43. wetting agents preliminary field trial and greenhouse study

44. Development of blue/green algae on a shaded putting green, 21 August 2006

45. Development of blue/green algae on a shaded putting green, 21 August 2006

46. Development of blue/green algae on a shaded putting green, 21 August 2006

50. influence of wetting agents and fungicides on algae development in turf, uconn greenhouse 2010

51. Summary of Wetting Agents Highly Variable/Conflicting Results Field vs. Greenhouse Among Wetting Agents In Combination With Fungicides Surfactants Creating “Dryer” Canopy Should Reduce Moisture and Possibly Algae More Work Needed

52. Conclusion of Research Info Preventive Suppression Possible With Phosphites (≤10.9 kg H3PO3/HA) Moderate Curative Suppression Excellent Control with Chlorothalonil/Mancozeb Improve Turf Density With Adequate N-Fertility Impact of Phosphorous Conflicting Acidifying Fertilizers May Directly Reduce Algae Wetting Agent Importance Unclear

53. Just Tell me what to do…

54. improve light penetration selective or clear cut tree removal

55. oxygenate the soil manage water infiltration, organic matter, etc.

56. increase drainage easier to add water than to remove it

57. increase drainage easier to add water than to remove it

58. retrofitting existing greens installed after the fact with little disruption to play Courtesy XGD Systems

59. manage moisture more fine-tuned information

60. manage water applications more precision to maintain “enough” water

61. nitrogen and n-sources ammonium sulfate, improve health, ↓ phosphorous?

62. utilize available pesticides chlorothalonil & mancozeb as well as phosphites

63. how much precision? every golf course is different. it’s up to you.

64. www.turfdiseases.org

65. Additional Questions? @johnkaminski