Course Report for August 2020 Board Meeting

The biggest issue on everyone’s mind are the greens due to the percentage of Poa Annua within the greens. Poa Annua or winter grass is not a new problem and has been around for decades on Pinjarra’s greens with some years worse than others.

At the moment the Poa Annua pressure on the greens is very high and there are a number of factors contributing to this –

  • Stopping the Growing Degree Day’s programme with the PGR (plant growth regulator) which has been in place for 5 years.
  • The reason for stopping the programme was due to the root zone depletion within the desired plant species Agrostis stolonifera (Creeping Bent grass).
  • Causing factors relating to root zone depletion are lack of renovation practices, e.g. coring, verti-draining and verti-mowing. This is especially evident on greens as old as ours, 50 plus years.
  • Poor quality bent (old variety). Pinjarra’s on course greens are growing Seaside Bent which is a variety that performs very poorly over the winter months by thinning down which in turn allows the winter grass to establish and dominate. It is also susceptible to herbicides at certain times.
  • Soil nutrients and water quality – currently soil and water tests are showing some adverse results.
  • Tree’s – shading and root invasion of our greens, some more than others depending upon variety of tree or tree’s growing around the greens and their close proximity.
  • Mowing practices – mowing too aggressively, e.g. too short in order to gain speed which through the winter months will speed up the thinning of the bent grass and in some cases turning to mud which allows the winter grass to dominate.

Programming ahead for the next year and onwards needs to change to try and minimise the above factors.  Improve the renovation practices in accordance with the age of the greens and rounds of golf played per year. The following will be implemented –

  • A return to two corings per year to refresh the soil structure and improve air movement and drainage.
    • The November coring will consist of –
      • double pass verti-cut and mow;
      • 25mm hollow verti-drain and sand 150-175mm deep;
      • 19mm hollow core and sand 80-100mm deep;
      • Over sow with Crystal Blue Links Bent; and
      • fertilise according to soil and water tests.
    • • End of March – early April coring will consist of –
      • double pass verti-cut and mow;
      • 16mm hollow core and sand; and
      • fertilise according to soil and water tests.
  • Verti-draining every 4-6 weeks, 8mm mini solids to improve aeration and drainage.
  • Dusting of greens every 2-4 weeks.
  • Revise the current fertiliser programme to reflect the soil and water tests. Water tests are showing higher sodium levels than the last tests and this is likely to be attributed to the declining rainfall over the past 3 years and higher pressures on the aquifer.
  • Continual pruning for improve air flow and sunlight. Investigate the feasibility of trenching around the greens as a root pruning solution, potentially every 2 years.
  • Educating members that speed on the greens at certain times of the year is to the detriment of the greens.
    • resting greens, e.g. no mowing on Sunday’s and possibly Wednesday’s
    • raising mowing heights through the winter months.

Summary
All of the above will be subject to available time, weather conditions and club competitions. A budget adjustment will need to be made to allow for additional fertilisers that are required to reflect the soil and water tests.

Please remember at the end of the day there is no miracle cure to eradicate Poa Annua. There are no chemicals available to remove poa from bent grass greens. We can limit or slowly reduce our percentage with the use of PGR’s but this is only shown to be a short term remedy and results fluctuate greatly with the change in seasons.
Most clubs and especially those in WA that have good budgets will go through a rebuilding stage on their greens to control Poa Annua and then use PGR’s to extend the greens life before it will eventually be riddled with poa and the process will start again.

I’m sure there is a lot more to be said but please keep in mind our greens are 50+ years old.

Good golfing to all
Neal Ward
Course Superintendent