Summer Green Speed Trial Pt 3 (Results)

Results are expressed in cm difference between the readings taken prior to the method being implemented and after.
Height of Cut and Rolling readings are expressed in cm difference at each point compared to the H.O.C. when at 3mm under present practices.

DAY
GROOM
TOP
GROOM & TOP
H.O.C /Roll
2
6
6.5
6.5

4
6.5
8
9.1

7
6
9.5
13.7

10
5.9
9.5
15.5

12
5.5
5.8
14.2

15
4.9
3.8
9.7

21
3.1
-1
3.6

Rolling 3mm



32
Rolling 2.8mm



57
2.5mm H



36
2.5mm HD



56
2.8mm H



25

                
                            
Impact on Turf Health
Grooming – The impact on turf health from mechanical injury was evident almost immediately (within 24hrs) stress signs of discolouration, thin weak areas developed which required extra maintenance intervention to sustain the greens in healthy condition. Plant protectants were required as increased disease activity was observed in the thin weak areas.
Based on results grooming would need to be carried out 3 weekly for consistency. The extra cost involved and risk to turf health during summer does not compare favourably to the minimal increase in speed.
Grooming during growing season results in greater increases in speed due to more green leaf material being removed.
Associated Costs / Risk level
2 x 2.5hrs Labour for operation
3hrs Labour for extra intervention per 3 week period
Intervention product  - $1100 plus per 3 week period during summer.
Risk to turf health - Severe

Dust In – Turf health impact was minimal, bruising occurred as a result of brushing the sand in, this didn’t pose any serious problems, the main issue with this method was applying the sand light enough, the hired sander was not uniform and the top dress was heavier than we anticipated, this meant it was longer time frame before mowers stopped picking up sand creating excess wear on cutting units.
In the most part there was a smoother ball roll and tighter knit of the surface 10 days after application.
Based on results fortnightly sanding would need to be carried out for consistency. Extra costs associated with this method included extra sharpening (x2) of cutting units compared unfavourably with the actual gain in speed and length of time of increased pace.
Associated Costs / Risk level
2 x 3hr Labour
Hire Dust In - $300 per 2 to 3 week period
Sharpening / Blades - $75 per Dust In
Intervention – $300 per 3 week period during summer.
Risk to turf health – Low to Moderate

Grooming and Dust In – Turf health impacts were similar to the individual methods but not to the same extent. In many ways both methods combined acted to counter act to some degree the issues raised individually. Sand pickup was less.
Based on results the process would need to be complete at least 4 weekly. The cost associated with the combination of both methods was more favourable in speed increase v’s turf health and cost impact.
Associated Costs / Risk level
2 x 2.5 Labour
2 x 3hr labour
Hire Dust In - $300 per 4 week period
Sharpening / Blades - $75 per 4 weeks.
Intervention - $800 per 3 week period summer
Risk to Turf Health – moderate to severe

Crab Grass Germination
It was noted 21 days after the trial using the above three methods, a large percentage of germinating crab grass was observed, prior to this crab grass control was satisfactory with minimal amounts. It cannot be confirmed or dismissed whether the grooming and dust in methods were the main cause of this. The theory is by thinning the greens allowing extra light and moisture into the surface and also providing a seed bed through grooming and sanding created conditions favourable to crab grass germination.

Rolling – Rolling showed the greatest increase of speed of all methods used, as rolling is less invasive than the other methods trialled, no immediate turf impacts were observed, however it must be noted the impacts from rolling are long term and could not be assessed during this trial, potential issues which are commonly experienced from rolling are – compaction, sealing of the surface reducing air and water flow into the profile, this could be alleviated with the extra cost of needle tinning x 2 over the course of the year. There is a greater cost involved with requirement of purchasing a golf green roller which needs to be compared to that of the greater increase in speed.
Associated Costs / Risk level
1 x 3hr Labour
Purchase of Roller - $8000
Needle Tine x 2 - $2000 each time  .
Risk to Turf Health - Undefined

Height of Cut – Tho not part of the trial, the opportunity arose to highlight the influence the height of cut has on green speed due to the timing of the ladies Summer Cup. Results show the height of cut as having the greatest influence on green speed under our existing practices with in our budget.
The clubs own experience over the years show summer cutting heights of under 3mm are unsustainable and has lead to disastrous outcomes under very high temperatures with loss of areas and in some cases total loss of green being experienced over the history of the club. Even through this trial the impact over the short period of time we lowered the H.O.C, visible stress signs were observed and extra intervention (tho planned as part of the preps for the Cup) were required

In an upcoming post I will discuss some recomendations based on the trial.

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