Michigan State University
Due to the recent harsh winter and new bentgrass varieties that have come into the market, a study currently underway at the Hancock Turfgrass Research Center at Michigan State University has become quite timely and relevant. Pure Distinction creeping bentgrass was seeded into a bare soil profile last August with the intent of using four factors (nitrogen fertilizer rate, mowing height, PGR use, and verticutting) to discover the fastest way to get a plot of turf capable of withstanding putting green traffic. Although the following observations are preliminary, we hope that those interested may find them useful.
As of May
29, 2014, only the nitrogen fertilization and mowing height regimens have been
implemented long enough to notice any treatment differences. The
most striking contrast is between the fertilizer
rates. Rates of 0.05, 0.10, and 0.15 lb N/1000 ft2 are sprayed
(initiated Sept. 2013) weekly. The photographs below reveal that the plots
receiving 0.10 lb N/1000 ft2 and 0.15 lb N/1000 ft2 of
fertilizer are much farther along than the plots receiving 0.05 lb N per week.
The differences between the two higher rates are currently harder to
differentiate, but the highest (0.15 lb N/1000 ft2) rate did seem to
grow in significantly faster initially than either of the other two rates. The
warm air and soil temperatures during the past couple of
weeks have given most of the 0.10 lb N/1000 ft2 plots a chance to
catch up to the highest rate, but the lowest rate plots still have
significantly less coverage than the others.
Pure Distinction 5/5/14.
|Pure Distinction 5/25/14. Darker green areas are 0.10 & 0.15 lb N/1000 ft2 rates and thin areas are the 0.05 lb N/1000 ft2 rate.|
Mowing was initiated last fall and resumed this year on April 30, 2014 yielded minimal clippings until the second week in May due to cold soil and air temperatures. Half of the plots were originally being mowed at 0.200” and the other half at 0.150”, with each height being reduced by 0.05” each week until a height of 0.125” is reached. Mowing heights are currently at 0.190” and 0.140”. Plots being mowed at the lower height are growing in more densely than areas at the higher cut, even though they look similar from a standing distance due to longer, more lateral growing leaves on the higher cut turf (see Figures 4-7).
Mowing height 0.190”. 5/30/14. Notice there are quite a few areas where the leaves are sprawling outward instead of standing up.
|Mowing height 0.140” 5/30/14. When compared to the higher mowing cuts the grass blades are more upright and less sprawling.|
The verticutting regimen was initiated on May 28, 2014. At the time this post was written, the cutting was too new to see any differences between plots. The PGR applications will began the week of June 1, 2014.