Course Update – August

Oh winter… We spend majority of the year praying for rain and now once it’s here we are wanting some warmth and sunshine. It hasn’t been our wettest winter but I can’t remember a winter that has had so much intensity in the volume of rain that has come down. The course is holding up fairly well but it is important that we stay mindful and avoid driving or walking through wet areas. No one likes roped off areas and the less we need to put out there is a win/win for everyone.

    

Kikuyu Control

Majority of the fairways have had their first of three applications as part of our annual kikuyu program. We are now into our 3^rd winter of the program and have seen a great reduction of kikuyu in our fairways. Previous years we predominately focused on the fairway plus and 1m into the rough, this year we have pushed that out to the tree line. Applications are based on 21 day intervals and should start seeing the kike yellow off within the next week.  

 

Poa Control – use of Poa Cure Herbicide

We have now completed 2 applications of the herbicide poa cure to our greens 1, 2, 4, 6, 8, 9, 12, 13, 16, & practice greens. The slow nature of the chemical is beginning to work with the poa yellowing off and starting to dissipate.

 

PoaCure Applications

1. First Application: On 18th June, PoaCure was applied at the label rate of 1.8L/ha over 0.5ha which equated to a tank rate of 900ml.
2. Second Application: On 19th July, a second application was carried out at the same label rate.
3. Future Applications: A minimum of four applications will be applied across the selected greens.

The following greens have been treated: 1, 2, 4, 6, 8, 9, 12, 13, 16, along with all three practice greens. Additionally, the bottom putter was sprayed as a future trial to address greens with a higher percentage and thicker sward of poa.

 

What is PoaCure?

PoaCure (methiozolin) is a selective herbicide specifically designed to target Poa within cool season grasses. The chemical operates through a mode of action that inhibits the cell wall biosynthesis within plant. How does it work?

1. Absorption and Translocation: PoaCure is absorbed primarily through the roots of the plant.
2. Cell Wall Inhibition: Once inside the plant, PoaCure disrupts the synthesis of key components in the cell wall, particularly affecting the regions where cell division and growth occur.
3. Gradual Decline: Over time, the disruption of cell wall formation leads to a gradual decline in the vitality of the Poa plant. This slow kill process allows time for bent grass to slowly fill in the gaps left by the dying Poa.

Is it working and what will we see?

1. Initial Yellowing: Poa annua will begin to show signs of stress and yellowing approximately 1-2 weeks after initial application.
2. Thinning and Decline: Over the next few weeks, Poa will thin out and eventually die, in this time we will expect to see some regrowth appear back within the plant but follow up applications will cover this.
3. Improved Bent Grass Density: As the Poa declines, bent grass will fill in the spaces. Early observations show bent visible within these patches – Some plugging and seeding of areas may be required.

 

Why Poa annua is Hard to Manage and Eradicate:

• Seed Bank: Poa annua produces a prolific number of seeds that can remain viable in the soil for years, leading to constant re-emergence, over the past couple of years ethephon has been used as a seed head suppressant with great effect.
• Adaptability: Poa annua can adapt to a wide range of environmental conditions, from wet to dry and from shaded to full sun areas.
• Competitive Growth: It has a rapid growth cycle, allowing it to quickly establish and outcompete bent grass, especially in stressed conditions.
• Cross-Resistance: Some Poa annua populations exhibit cross-resistance to multiple herbicide classes, making it challenging to manage using standard herbicide treatments. This cross-resistance complicates control strategies and the use of different management practices.

1. Shade:

• Impact: Shade reduces the ability of the plant to perform photosynthesis resulting in weakening turf along with the surface remaining wet promoting perfect conditions for Poa to thrive.
• Management: Pruning surrounding tree’s and allowing adequate airflow through the area.

2. Heavy Traffic:

• Impact: Frequent foot and machinery traffic compacts the soil, stressing turf and creating conditions favourable to Poa. Additionally, Poa can spread via foot traffic, as seeds are easily transported through the spikes on golf shoes and course machinery.

3. Compacted Soils:

• Impact: Compacted soils hinder root growth and water infiltration, weakening turf and creating moisture to sit in the upper profile. 
• Management: Regular aeration and regular dustings with sand can alleviate compaction, improve soil structure, and maintain thatch levels.