An eclectic list of references


I've just finished reading through a selection of 40 articles from the マイカの時間 series that I write for ゴルフ場セミナー magazine in Japan. That's 49,015 words in English about greenkeeping, water, soil, temperature, light, organic matter, playing conditions, and fertilizer.

I put together this reference list for articles and books that I mentioned in those 40 articles. It's an eclectic list. You might like to have a look at these. Perhaps you'll turn up an article that you would like to read sometime.

More details and the full list in this document. And here is a list of all the references.

Update: I have generated the reference list again to include links to each item, and I added an item from Pat Gross.

Allen, R. G., Pereira, L., Raes, D., & Smith, M. (1998). Crop evapotranspiration: Guidelines for computing crop water requirements. FAO irrigation and drainage paper 56. Irrigation and drainage paper (Vol. 56, pp. 377–384). Rome: FAO. Retrieved from http://www.fao.org/docrep/X0490E/X0490E00.htm

Baldwin, C., & Liu, H. (2008). Altered light spectral qualities impact on warm-season turfgrass growth and development. USGA Turfgrass and Environmental Research Online, 7(9), 1–12. Retrieved from http://usgatero.msu.edu/v07/n09.pdf

Bauer, S., Lloyd, D., Horgan, B. P., & Soldat, D. J. (2012). Agronomic and physiological responses of cool-season turfgrass to fall-applied nitrogen. Crop Science, 52(1), 1–10. https://doi.org/10.2135/cropsci2011.03.0124

Beard, J. B., & Beard, H. J. (2005). Beard’s turfgrass encyclopedia for golf courses, grounds, lawns, sports fields. East Lansing: MI: Michigan State University Press. Retrieved from http://tic.msu.edu/tgif/flink?recno=93886

Brede, A. D. (1991). Correction for slope in green speed measurement of golf course putting greens. Agronomy Journal, 83, 425–426. https://doi.org/10.2134/agronj1991.00021962008300020032x

Bunnell, B. T., McCarty, L. B., Faust, J. E., W. C. Bridges, Jr., & Rajapakse, N. C. (2005). Quantifying a daily light integral requirement of a “Tifeagle” bermudagrass golf green. Crop Science, 45, 569–574. https://doi.org/10.2135/cropsci2005.0569

Carrow, R. N. (2003). Surface organic matter in bentgrass greens. USGA Turfgrass and Environmental Research Online, 2(17). Retrieved from http://usgatero.msu.edu/v02/n17.pdf

Dest, W. M., Guillard, K., Rackliffe, S. L., Chen, M. H., & Wang, X. (2010). Putting green speeds: A reality check! Applied Turfgrass Science. https://doi.org/10.1094/ATS-2010-0216-01-RS

Ervin, E., & Nichols, A. (2010). Organic matter dilution programs for sand-based putting greens in Virginia. USGA Green Section Record, 48(16), 1–4. Retrieved from http://turf.lib.msu.edu/gsr/article/ervin-nichols-organic-9-24-10.pdf

Gault, W. K. (191x). Practical golf greenkeeping. The Golf Printing; Publishing Co., London, England. Retrieved from http://tic.msu.edu/tgif/flink?recno=33203

Gelernter, W., & Stowell, L. J. (2005). Improved overseeding programs: 1. the role of weather. Golf Course Management, 73(3), 108–113. Retrieved from http://tic.msu.edu/tgif/flink?recno=102720

Gross, P. (2012). Hand watering greens at the U.S. Open. USGA Regional Update. Retrieved from http://tic.msu.edu/tgif/flink?recno=207427

Guertal, E., & Han, D. (2009). Timing of irrigation for cooling bentgrass greens with and without fans. USGA Turfgrass and Environmental Research Online, 8(17), 1–5. Retrieved from http://usgatero.msu.edu/v08/n17.pdf

Hall, A. D. (1912). The book of the links: A symposium on golf. In (pp. 31–45). London: W. H. Smith & Son. Retrieved from http://tic.msu.edu/tgif/flink?recno=134903

Hamilton, G. W., Livingston, D. W., & Gover, A. E. (1994). The effects of light-weight rolling on putting greens. London: E.; F. N. Spon. Retrieved from http://tic.msu.edu/tgif/flink?recno=25095

Hartwiger, C. (2004). The importance of organic matter dynamics: How research uncovered the primary cause of secondary problems. USGA Green Section Record, 42(3), 9–11. Retrieved from http://turf.lib.msu.edu/2000s/2004/040509.pdf

Hartwiger, C. E., Peacock, C. H., DiPaola, J. M., & Cassel, D. K. (2001). Impact of light-weight rolling on putting green performance. Crop Science, 41(4), 1179–1184. https://doi.org/10.2135/cropsci2001.4141179x

Hartwiger, C., & O’Brien, P. (2001). Core aeration by the numbers. USGA Green Section Record, 39(4), 8–9. Retrieved from http://tic.msu.edu/tgif/flink?recno=68543

Jordan, J. E., White, R. H., Vietor, D. M., Hale, T. C., Thomas, J. C., & Engelke, M. C. (2003). Effect of irrigation frequency on turf quality, shoot density, and root length density of five bentgrass cultivars. Crop Science, 43(1), 282–287. https://doi.org/10.2135/cropsci2003.2820

Kaminski, J. E., & Dernoeden, P. H. (2005). Nitrogen source impact on dead spot (ophiosphaerella agrostis) recovery in creeping bentgrass. International Turfgrass Society Research Journal, 10(1), 214–223. Retrieved from http://tic.msu.edu/tgif/flink?recno=105374

Karcher, D., Nikolai, T., & Calhoun, R. (2001). Golfer’s perceptions of green speeds vary: Over typical stimpmeter distances, golfers are only guessing when ball-roll differences are less than 6 inches. Golf Course Management, 69(57-60). Retrieved from http://tic.msu.edu/tgif/flink?recno=72405

Karnok, K., & Tucker, K. (2008). Using wetting agents to improve irrigation efficiency: Greens with a water repellent root zone require less water when treated with a wetting agent. Golf Course Management, 76(6), 109–111. Retrieved from http://tic.msu.edu/tgif/flink?recno=136496

Kussow, W., & Houlihan, S. (2006). The new soil test interpretations for Wisconsin turfgrass. Wisconsin Turfgrass News, 24(1), 1, 14–16. Retrieved from http://tic.msu.edu/tgif/flink?recno=151815

Lawes, J. B., & Gilbert, J. H. (1859). Report of experiments with different manures on permanent meadow land. part III. description of plants developed by different manures. Journal of the Royal Agricultural Society of England, 20, 246–272. Retrieved from http://tic.msu.edu/tgif/flink?recno=179487

Lloyd, D. T., Soldat, D. J., & Stier, J. C. (2011). Low-temperature nitrogen uptake and use of three cool-season turfgrasses under controlled environments. HortScience, 46(11), 1545–1549. Retrieved from http://hortsci.ashspublications.org/content/46/11/1545.full

Nikolai, T. A. (2004). The superintendent’s guide to controlling putting green speed. Wiley. Retrieved from http://tic.msu.edu/tgif/flink?recno=94696

Nikolai, T., Rieke, P., J. N. Rogers III, & J. M. Vargas Jr. (2001). Turfgrass and soil responses to lightweight rolling on putting green root zone mixes. International Turfgrass Society Research Journal, 9(2), 604–609. Retrieved from http://tic.msu.edu/tgif/flink?recno=74233

O’Brien, P., & Hartwiger, C. (2003). Aeration and topdressing for the 21st century. USGA Green Section Record, 41(2), 1–7. Retrieved from http://turf.lib.msu.edu/2000s/2003/030301.pdf

Piper, C. V. (1924). Grass experiments at Rothamsted, England. Bulletin of the Green Section of the USGA, 4(4), 101–104. Retrieved from http://tic.msu.edu/tgif/flink?recno=49247

Piper, C. V., & Oakley, R. A. (1921). Rolling the turf. Bulletin of the Green Section of the USGA, 1(3), 36. Retrieved from http://tic.msu.edu/tgif/flink?recno=47552

Pippin, T. (2010). The five-day program: Alternative philosophy for managing your topdressing program. USGA Green Section Record, 48(1), 17–19. Retrieved from http://turf.lib.msu.edu/gsr/2010s/2010/100117.pdf

Pote, J., Wang, Z., & Huang, B. (2006). Timing and temperature of physiological decline for creeping bentgrass. Journal of the American Society for Horticultural Science, 131(5), 608–615. Retrieved from http://journal.ashspublications.org/content/131/5/608.short

Sartain, J., & Kruse, J. (2001, April). Selected fertilizers used in turfgrass fertilization. University of Florida Extension CIR 1262. Retrieved from http://ufdcimages.uflib.ufl.edu/IR/00/00/31/23/00001/SS31800.pdf

Soper, D. Z., Dunn, J. H., Minner, D. D., & Sleper, D. A. (1988). Effects of clipping disposal, nitrogen, and growth retardants on thatch and tiller density in zoysiagrass. Crop Science, 28(2), 325–328. https://doi.org/10.2135/cropsci1988.0011183X002800020030x

Turgeon, A. J. (2008). Turfgrass management 8th ed. Pearson Prentice Hall. Retrieved from http://tic.msu.edu/tgif/flink?recno=127766

USGA. (2012). Stimpmeter instruction booklet. Far Hills, NJ. Retrieved from http://tic.msu.edu/tgif/flink?recno=70149

USGA Green Section Staff. (2004). USGA recommendations for a method of putting green construction. USGA web site. Retrieved from http://tic.msu.edu/tgif/flink?recno=94463

Watson, J., & Knowles, T. (1999). Leaching for maintenance: Factors to consider for determining the leaching requirement for crops. Arizona Water Series, 22, 1–3. Retrieved from http://extension.arizona.edu/pubs/az1107.pdf

Xu, Q., & Huang, B. (2000a). Effects of differential air and soil temperature on carbohydrate metabolism in creeping bentgrass. Crop Science, 40(5), 1368–1374. https://doi.org/10.2135/cropsci2000.4051368x

Xu, Q., & Huang, B. (2000b). Growth and physiological responses of creeping bentgrass to changes in air and soil temperatures. Crop Science, 40(5), 1363–1368. https://doi.org/10.2135/cropsci2000.4051363x

Zontek, S. J. (2009). When the going gets tough, go back to basics. USGA Green Section Record, 47(4), 28. Retrieved from http://turf.lib.msu.edu/2000s/2009/090728.pdf

How to lose 120 million yen with frost delays

I'm bombarded at this time of year with reminders, notices, descriptions, and articles telling me about the importance of frost delays. Apparently, frost delays are essential for the health of the turf. Allow play on frozen or frosted turf, and the leaves will turn brown and start to die. In a worst case scenario, recovery from the damage could take months.

This is a story about something completely different. How about no frost delays at all, and removal of snow by any possible method so the course can remain open? That's the approach used at well over 1,000 golf courses in Japan. I guess there are about 600 courses that are at such a high elevation or are so far north that they close for the winter; at the remaining courses, golf is a year round sport.

I will admit, I was terrified to allow play on frosted turf when I was a superintendent in Japan. I'm sure I protested, explained how much the grass would be damaged, said I would not take responsibility for the damage, and so on. But much to my surprise, the damage was negligible and temporary.

I wrote about how temporary the damage is in this post about winter traffic on frozen bentgrass. As a follow-up to that, I was asked if it mattered if it was a leaf frost or a ground frost. I said I didn't know, but I would look up the temperatures from that winter and share some more details of my experience.

Here's the story.

This was at Habu CC in Chiba prefecture. The greens were Penncross creeping bentgrass, the tees and fairways were Tifway 419 bermudagrass overseeded with perennial ryegrass, and the roughs were noshiba (Zoysia japonica). Here's the 15th in November.


The course is at an elevation of 120 m. I downloaded the daily temperature data for the winter of 2000/2001 from the nearby JMA Sakahata weather station, which is also at 120 m. I think these temperatures are similar to those at the golf course.


From 29 November 2000 until 2 April 2001 there were 73 days with a low of 0°C or below. I think frost can form on the leaves even when the air temperature is above 0°C, but I'll stick with 73 days as an estimate of mornings with frozen or frosty turf.

In Japan, it is customary to do a two tee start, with tee times at 7 minute intervals, the golfers stopping for a meal at the clubhouse before starting their second nine. At Habu, there were about 3,000 rounds per month in the coldest months of that winter -- maybe more -- and 4,000 to 5,000 rounds per month in November, March, and April.

I wanted to implement frost delays, but it was impossible. The golfers wanted to play, and the owner wanted to accept their money. Let's say for each of those 73 days with frozen or frosted turf, we did not allow the golfers to play for 2 hours in the morning. That's 2 hours of tee times off 2 tees, on 7 minute intervals, which comes to 137 golfers. Let's say the green fee was 12,000 yen. And let's lose those customers for 73 days. 137 times 12,000 times 73 = 120,000,000 yen. That's about a million USD. The only days we had to close were when we could not clear the snow. But we were trying everything possible to clear it. That's some serious money.



So how about the grass? How much damage was there? On the tees and fairways, the damage was negligible. Of course traffic on slow-growing turf is going to beat it up a little bit. I did not notice that the traffic on frost or frozen ground added to that.

On the greens I was really worried. Courses with more staff would typically put covers out on the greens, at least over the area where the day's hole location would be. We did that as much as we could, but we could not cover all the greens, or even cover all of a single green, with the limited covers and staff that we had.

I've looked through old photos. This is the worst spot on the practice putting green in January. The putting green got a lot of traffic every morning. Pretty ugly.


This, in February, is the worst spot on the 11th green, which was shaded until mid-morning in winter.


That was as bad as it got. By March, even though frosts were still happening, the grass filled in. The damage had not been nearly as bad as I'd expected.


In fact, the greens were cored on March 27. But winter still wasn't over.



By April, there wasn't a hint of damage from all the traffic. No grass was dead, any thin spots were gone, and the grass was growing like crazy.



I'm not sure there's a moral to this story, other than one must do what is in the best interest of the facility. In the case of Habu CC that winter, it was best to have customers playing the golf course.

Daily versus monthly calculations of ET and irrigation requirement

I showed how weather data can be used to calculate a daily soil water balance. One can adjust the rootzone characteristics, and the timing and amount of irrigation, so that the calculations are representative of what one wants to know.

By keeping track of what the soil water content would be on each day, given the actual weather conditions, and given the water holding capacity of the specified rootzone, one can find how much irrigation water would be required.

I've also made calculations using the standard method, which takes the evapotranspiration (ET) and subtracts the effective rainfall. I've used this method before to make calculations, and it made sense to me, but I've realized that this method doesn't account for rootzone depth. For turfgrass, one should probably adjust the effective rainfall calculation for each site based on the rootzone depth.

I wondered if these methods give a similar result in predicting the irrigation requirement. I had daily data from Sapporo from 2013 to 2015, and I also got the monthly averages or totals for the same time period. I've just made some calculations to find out.


I looked at the months from April to October in each year. That's a total of 21 months.

For the ET, the result is almost the same whether it is calculated daily, and summed for a month, or whether one calculates ET using the monthly data.


For the irrigation requirement, there is not a consistent agreement. I made these calculations based on an approximation of a loam soil with a 10 cm rootzone depth, a field capacity of 40% (by volume), with irrigation supplied to return the soil to field capacity when soil water content would drop below 20%.


I've got some more calculations to make about this. The standard method seemed pretty good to me until I started making the daily calculations.

The daily soil water balance at Sapporo from 2013 to 2016

One can calculate a water budget for a particular location to get an estimate of how much irrigation water is required. This article from the Green Section Record describes those calculations.

If one considers the depth of the rootzone, and then steps day by day through the year, the irrigation water requirement can be calculated as part of the daily soil water balance.


I downloaded data for Sapporo for the past few years. Since the ground is covered in snow during the winter, I'll just show the daily water balance from 1 April to 31 October. This is for a simulated 10 cm rootzone with a field capacity of 23% and irrigation applied to keep the soil from dropping below 10%. That will be something like a golf course putting green. The blue line shows the soil water content. The black circles show the irrigation events. Interesting stuff.





Dog's footprint and grass susceptibility to this disease

I don't like turf diseases. If there is any fun in them, for me, it lies in only two things. First, is it a particularly well-named disease? Second, how awful are the symptoms?

I enjoy learning disease names and finding those that have the most interesting names. Nothing against brown patch and yellow patch, but those are pretty bland. Dollar spot is more interesting, and elephant's footprint even more so.

Then there are the symptoms. All turf diseases, if left unchecked, can make some hideous symptoms. In their standard form, however, I find some to be more hideous than others. Yellow patch, anthracnose, red thread -- often present, but sometimes only visible to those actually looking for symptoms. Compare to a disease like large patch, which in its standard manifestation is monstrous.

Using those criteria of interesting names and hideous symptoms, one of my favorite diseases is inu no ashiato -- dog's footprint. The name is interesting, and the symptoms are moderately hideous. I was glad to see this new article by Tomaso-Peterson et al. about Curvularia malina sp. nov. inciting a new disease of warm-season turfgrasses in the southeastern United States. From the introduction:

A foliar disease of these warm-season turfgrasses is often observed following prolonged or significant precipitation events such as tropical storms and hurricanes. The disease manifests as distinct chocolate brown to black spots (2–15 cm diam) that appear on Cynodon dactylon or Zoysia matrella putting greens, fairways, and tee boxes. Under high disease pressure the dark spots may coalesce to form large, irregular areas of blighted turfgrass.

"Is this the same as dog's footprint," I wondered?

A Curvularia leaf blight affecting Zoysia spp. in Japan, referred to as dog footprint, shares symptomology to that observed on C. dactylon and Z. matrella in the southeastern United States ... Based on these reports, our hypothesis is that the sterile fungus associated with Curvularia blight and causing similar symptoms in stands of C. dactylon and Z. matrella in the southeastern United States is a novel species of Curvularia.

The species was identified as Curvularia malina.

To date, C. dactylon and Z. matrella are the only golf course grasses from which C. malina has been isolated. Disease epidemics on Z. matrella appear to be more severe than on C. dactylon based on visual field observations. The disease is most prevalent in the spring and fall, which are normally characterized by moderate temperatures and ample precipitation. Symptoms may persist into the summer if prevailing environmental conditions remain favorable and the turfgrass experiences stress from intensive management practices.

So far so good. Dog's footprint is more severe on Z. matrella in Asia than on C. dactylon. However, in Asia the disease is most prevalent in summer, or in conditions characterized by warm temperatures and ample precipitation.

Based on the results of our research, C. malina induces disease symptoms in warm-season turfgrasses similar to those associated with Curvularia leaf blight.

It seems dog's footprint is caused by C. malina. Manilagrass (Zoysia matrella) can get lots of diseases, but in a tropical environment, this species is infected by few diseases, with the most common being dog's footprint.

Here is dog's footprint on manilagrass at Hilo in March.

This is at Okinawa in August.

This is at Manila in August.

This is at Shizuoka in July.

Those are pretty typical symptoms. And they are all on a monostand of one type of manilagrass.

I've noticed that some manilagrass varieties are often showing dog's footprint symptoms, and other varieties rarely do. I usually see this at two different locations in the same town. For example, lots of dog's footprint at site X, and then an hour later at site Y, a slightly different type of manilagrass has no dog's footprint.

Last July, I saw this at one location, on a golf course fairway with a mixed stand of different Z. matrella (korai) varieties and with some patches of C. dactylon.

On one variety of korai, lots of dog's footprint. On the Cynodon and other variety of korai, none.

This disease is ubiquitous on susceptible varieties in East and Southeast Asia. Finding varieties that are less susceptible seems quite possible.

"Anyone who's played golf in Japan will know that many clubs have two greens on each hole"

Selection_101Fred Varcoe wrote about putting greens on Japanese golf courses in the August 2016 issue of Euro Biz Japan. The article, Know your greens (pdf, 3 MB), includes some quotes from me about bentgrass, korai, and how balls roll on putting greens.

For more about the two green system in Japan, see:

And kind of on this same topic, but of more general interest, see Paul Jansen's post on The Japanese Golf Experience.  You'll see more than just grass: breakfast beer, tiny hotel rooms, hot springs, cold springs, blue balls, green tea, and a volcanic eruption.

Shiny app shows the temperature and sunshine combination for 11 cities in Japan


I made a Shiny app with climatological normals data from the Japan Meteorological Agency to show the combination of sunshine and temperature at 11 locations.

@naturalgolf_D asked "What kind of situation is Japan?" With these data, I think it is interesting to compare different locations of interest, and a Shiny app is an easy way to do that.

Six more Shiny apps from ATC are here.

Clipping volume variation from green to green

Ryo Ishikawa won the KBC Augusta tournament at Keya GC in Fukuoka this week. Before the tournament started, he was so struck by the green conditions that he wrote about it on his website.


During the tournament, he putted well, with 27 putts Thursday, 26 Friday, 24 Saturday, and 26 Sunday. He had no three putts and 41 one putts on these korai greens during the tournament.

The greenkeeping staff at Keya GC measure the volume of clippings from 12 greens when the greens are mown. I shared some photos of this process, and some of the results during the tournament this year, in these messages:

I wondered how the clipping volume at Keya GC during the tournament this year compared to other courses. I also wondered if the variation in clipping volume from green to green during the tournament was different from clipping volume variability during a regular week.

To do that, I looked at clipping volume from 7 consecutive days in which greens were mown. Data from Keya during tournament week in 2016 are in the chart below, along with data from the last 7 mowing days at Keya during July 2016, and data from earlier this year from two different courses with cool-season grass.


As far as consistency in the volume of clippings, the tournament data looks impressive. I would expect that this consistency in clipping volume would result in more consistent ball roll on the greens during a tournament compared to everyday play.

I wanted to look also at the variability in clipping volume from green to green on a particular day. Is the variability in clipping volume from green to green lower during the tournament maintenance? To do that, I calculated the coefficient of variation (cv) for these same data. The cv is the standard deviation (σ) divided by the mean (μ).


I like that the cv during the tournament week was on a downward trend. I don't see a huge difference in the overall cv -- the mean cv for these dates is 0.31 for C3 grass #1, 0.37 for C3 grass #2, 0.32 for Keya at KBC Augusta 2016, and 0.32 for Keya during the last 7 mows of July.

One might speculate that greens with the same growing environment and the same soil and the same grass would have a lower cv. The cv shown here may represent some indication of the microclimate effect on growth across a property.

Something you don't see every day

Next week is the KBC Augusta (KBCオーガスタ) tournament at Keya Golf Club in Japan.

This is a rare event -- a professional golf tournament played on korai (Zoysia matrella) greens.

For more about this grass and these type of greens, see:

I may share a few photos and observations from the tournament. If I do, I'll use the #KBCオーガスタ hashtag. You can also find out more about this grass and its maintenance at the Keya Golf Club Turfgrass Maintenance page or by following Keya GC superintendent Andrew McDaniel.

Is it normal to be cloudy like this?

2016-07-17 10.23.40

On July 17, I was in the Tokyo area with Jim Brosnan. The daily light integral (DLI) in Tokyo on July 17 was 14.2 mol/m2. Jim asked me if it was exceptionally cloudy that day. Not really, I answered. I told him that the such cloudiness was normal.

Now that July 2016 is over, I looked at the DLI for every day in July at Tokyo and also at Batesville, Arkansas. Both are at about 35.7°N latitude, so the day lengths will be identical.

The lowest DLI at Batesville in July was 22.8 mol/m2 on July 29. In Tokyo, there were 10 days in July with a DLI less than 22.8 mol/m2, including 5 days with a DLI less than 10 mol/m2. In that context, the cloudiness on July 17 was not exceptional.

To see more, check out the average hourly PPFD and DLI values for Tokyo in this chart and for Batesville in this one.