These data are collected not only during the tournament week, but throughout the year when the greens are mown.
I wrote more about this process in these posts:
Andrew McDaniel, the greenkeeper at Keya GC, shared the clipping yield data with me and I've summarized it in these charts.
The average daily clipping yield, plotted week by week through the year, shows that the grass starts growing at the end of March, reaches a peak in the hottest weather of July and August, before dropping down due to tournament preparations. This reduction in clipping volume is achieved by reducing the N rate, only adding irrigation to prevent dry spots, and applying trinexapac-ethyl.
Looking just at August of 2015, one sees there were 4 days when the greens could not be cut due to heavy rain. One of those days was 25 August, the Tuesday of tournament week, when a typhoon came through. Not surprisingly, the clipping volume is larger on the day after a missed mowing.
Looking at clipping volume every day in 2015, it is even more clear when the grass starts growing in the spring, and also that the korai doesn't really grow until after the rainy season, when the temperatures increase. It is only in July and August when the grass is growing quickly. This chart also shows the days during the season when the greens could not be mown.
Looking at clipping volume for the 2013, 2014, and 2015 KBC August tournaments, one can see the 2014 and 2015 tournaments had less than 1 liter per 100 m2 from Thursday through Sunday. Based on measurements of green speed and evaluation of ball roll, the goal in 2016 will be to get the clipping yield down to the 1 liter level by the start of tournament week.
What about the work that was done to get this clipping volume, and the conditions produced?
- On the greens at Keya GC, 8.5 g N and 3.5 g K/m2 since the start of 2015.
- Mowing height for the tournament was 2.6 mm with the Shibaura 22 inch GEXE.
- Except when adjusted due to weather, the greens were mown 2x each morning, then rolled with a Toro lightweight roller, and then were mown 1x at the end of the day.
- Primo Maxx and soil surfactants applied to the greens.
- Irrigation added as necessary to prevent dry spots.
- Morning green speed during the tournament rounds ranged from 10.7 to 11.2 feet.