Turf quality ratings

Today, I discussed the intricacies of rating plots for turf quality with Dr. Richardson. This is a subjective rating and all raters would rate differently based on the individuals criteria. Since we are working on a bentgrass putting green situation, density and uniformity will be the crucial criteria within turf quality ratings. We also believe that these two characteristics will be the ones that are altered with our treatments.

Just wanted to write out some of the basic rules/thoughts that will help my rating skills.

1. Best to rate plots on cloudy days whenever possible. If I have to rate plots on a sunny day, be sure to stand with the sun to my back (cast shadow toward plots being rated).
2. Don't wear sunglasses when rating plots
3. Go with an initial thought and rating at first glance; Don't over think it!
4. If rating for color it is best to rate this from a distance.

At this point, there are few differences in the treatments because temperatures have not began creeping upward that would help differentiate treatments. We did see some potential differences in plots that were rolled 6 days a week. They appeared slightly less dense when comparing to other rolling treatments. This was a consistent observations in many of the plots. Also, the higher mowing height appeared more "splotchy" due to the increased leaf area. This observation compared to the lower mowing height where turf was relatively tight with higher density and finer leaf texture.

To help better separate plots color, digital images were obtained using the light box. Two images were collected in each plot and data will be averaged for the two images. Once plots are split and traffic treatments are being applied, a single image of each plot will most likely be obtained.

Root analysis

A preliminary root analysis was performed on my research plots around the end of May or first of June. Twelve samples were collected from randomly selected plots. The samples were washed to remove sand and organic matter from the samples. For analysis, two centimeters of turf and thatch material was removed from the top of the sample. The remaining organic matter was removed in a bucket of water. The root samples were separated in a clear dish prior to putting them in the WinRhizo root scanner. Data was obtained from this analysis.

Further root sampling of all plots was performed on June 10 and 11, 2010. Two samples were obtained from each plot using a profile sampler to a depth of 10 cm. Only one sample was obtained from plots previously analyzed in the preliminary sampling. Prior to washing samples a thatch depth measurement was recorded for each sample because the thatch layer is extremely thick. This data may be more useful for the ball mark analysis. Sand and organic matter were removed from each sample by placing the samples in the clipping collection device with an metal mesh to allow sand and organic matter to pass through. All samples were washed on June 11, 2010 requiring approximately 6 hours to wash 96 samples.

Root analysis was performed using the WinRhizo once again. This was a laborious process, but I was able to finish analyzing all samples in approximately 12 hours. Once root material was analyzed, the two samples from each plot were combined and placed in a drying oven for 24 hours at 100 degrees C. Dry weights of roots will be obtained following the drying period.

I will have to work with the data from the txt file in excel to determine what each cell in the Excel file refers to. I feel that overall root length will be the best data. The fine roots of creeping bentgrass were difficult to separate fully, so if multiple roots were stacked on top of each other or in a group, the software believed this was a larger diameter root when it may not have actually been. A second problem was the small amounts of organic matter that were not able to be washed off the roots. These larger particles were analyzed as roots as well. Each sample was similar though, so data should be sufficient for this information.

I believe these roots should be the largest and highest quanity I will be analyzing. I believe that later in the summer, roots will begin diminishing and dying off. Future measurements may result in less root material that may separate more easily.

Ball mark analysis

A preliminary study to determine methods for analyzing ball mark volume and recovery was performed on the NTEP bentgrass putting green. Two ball marks were created in each plot with the golf ball launcher at 40 psi. A red golf ball was placed in each ball mark and digital images were obtained using the newly developed ball lie device. One image was taken in the direction of the balls impact, and a second image was obtained from the opposite side. These images were analyzed to determine the percentage of ball above the canopy. These two values were averaged to determine the percentage of ball above the turf canopy. A single TDR measurement was also recorded for each plot to see if moisture levels affect ball mark size.

Ball marks were not repaired for 3 to 4 hours to allow turf within the ball mark to become injured. Ball marks were repaired with a standard ball mark tool. To determine recovery of ball marks, digital images were obtained with a light box of ball marks 2, 5, and 8 days after creating ball marks. These images will be analyzed using SigmaScan software to determine the time required for ball marks to recover.

Following 8 days of recovery, some of the ball marks appeared to be completely healed, so images will no longer be collected on the test area.

Corrections that should be made for future studies. To ease the time it takes to collect digital images for recovery, I should mark two corders of the shield, so I know exactly where ball marks are and where to place the shield. If dollar spot symptoms are evident, it becomes difficult to distinguish dollar spot symptoms and ball marks. However, ball marks appeared to have darker color in most cultivars compared to dollar spot symptoms.

Dollar spot appears

This morning when I went out to mow the plots at the farm, the SR 1020 was hammered with dollar spot. It appeared to be pretty consistent on all the mowing heights. Since we have not started applying all the treatments, I did not worry with rating the plots for severity. The weather has been warm and humid the last couple of days. We have been having some pretty severe thunderstorms over night and some during day time hours.

We went ahead and sprayed Headway (azoxystrobin + propiconazole) on the green to try and curratively control the small outbreak. The green is kept pretty lean on N compared to many locations, so reduced N may also help give Sclerotinia an edge.

Hopefully this application will whipe it out and we can move forward. This may be a good sign that we will be able to get some data on Dollar spot severity differences if they are visible with our treatments.

Peace out.

Plots are established and began mowing

I began mowing my plots at the farm on May 4, 2010. Initially, I only mowed the plots that would be maintained at 0.100 and 0.125 at 0.125 inches. The 0.156 plots were not mowed the first two days to allow them to increase in height, but were first mowed on Thursday May 6, 2010. The mowing heights of the 0.100 plots were slowly decreased throughout the past 0 days. Today, May 12, 2010 was the first time these plots were mowed at 0.100. I will mow them at these heights for a day or two before beginning rolling treatments. Rolling treatments are going to consist of rolling plots 0, 3, or 6 times per week.

The mowing treatments are going pretty well. One issue that may arise in the future is the need for some type of movable mat to turn the mower on. At this point, I am turning the mower in the alleyways, but it seems this may wear them out quickly, especially in the summer months when temperatures become higher. At this point, I am considering ordering walk away mats for this purpose.

Things are going to be picking up quickly now, so post will probably become more frequent if this methods seem to be successful.

New Device to measure ball mark volume

The previous post explains the techniques used to photograph golf balls within a ball mark created by the golf ball launcher. The original ball lie device designed to measure ball lie on various grasses at fairway heights was not conducive for capturing images of the golf ball in the ball mark. The base holding the camera is raised slightly, so images appear to cut off a portion of the ball. Our original thought was to raise the back end of the platform to create an angle that would capture the entire ball without losing the depth of ball in the ground. As the back end of the device was raised more ball was cut from the picture.

To solve this issue, photographs were taken with the camera set on the ground with care to have the camera 10-1/4 inches from the back of the ball lie device. The approriate focal length is imperative based on previous preliminary studies.

A new device will be created that will allow the camera to be fixed in a position flatter on the putting surface to ensure the entire ball can be photographed.

More to come as studies continue.

Ball Mark Volume Preliminary Study

Today, we worked with the digital imaging analysis to determine if we can distinguish differences in ball mark volume using digital images. Ball marks were greated in the putting green at various air pressures. A ball mark was created at 30, 40 50, 60, and 70 psi of pressure. At 30 psi we got a small impression that was hardly noticable. At 50, 60, and 70 psi, we were able to get much larger ball marks, but the shape of the mark was interesting. At 50 and 60 psi the ball marks were more conical. I assume this result is from the ball bouncing out of the mark. The ball basically plugged in the ball mark at 70 psi.

Two balls were fired high into the air to create ball marks from the ball descending due to gravity. The two ball marks were captured with the digital camera to correlate those ball marks to the ones shot into the green at the various psi's listed. Based solely on visual camparisons, the ball mark at 40 psi appeared most similar to the ones created with the ball landing on the green from high arching golf balls.

Studies may need to be performed to measure ball marks using the ball lie system on actual golf shots landing on a green. We also need to determine or find the terminal velocity of a golf ball striking a green from a golf shot. The one aspect of a golf shot that was not incorporated at this point is backspin created when hitting a golf shot into the green.

Two digital images were captured with a red golf ball sitting in the ball mark created. The control (ball sitting on the green) and subsequent pressures were photographed corresponding to photographs bmvdia1-bmvdia12. Photographs bmvdia13-bmvdia16 were taken of the two golf balls launched high into the air to determine the size of those ball marks. The last four pictures need to be compared to the previous photographs to determine the optimum psi to fire golf balls at the green.

Pictures will be analyzed using software tomorrow to determine what differences occurred.

General information and objectives of research

I am starting this blog to keep up with my PhD research. This is going to be my way of keeping up with what I do and learn throughout my years at the University of Arkansas in Fayetteville. For my research, I am going to work on determining the physiological effects of low mowing, rolling, and foot traffic on creeping bentgrass putting greens in the transition zone.

We are going to look at the basics for turf research to differentiate treatments. We will also be measuring photosynthesis and respiration of plots experiencing the various treatment combinations. To go along with photosynthesis and respiration, we are planning on extracting, identifying, and quantifying individual carbohydrate fractions within the putting green. One of the parts that is really exciting, is the ball mark resistance and recovery. Those are the objectives I will be trying to figure out and measure throughout the next few years.

I am planning on just keeping up with what I am doing on a regular basis, so I can use this as a tool to remember things in the future when I need them. If this looks like an enjoyable topic to you, feel free to read posts in the future.

Ball mark volume study

I was trying to quantify ball mark volume by using our digital imaging analysis setup. SigmaScan software is used to pick out red pixels of a golf ball to determine golf ball lie, green color, or establishment of various grasses. A small side study was performed recently to correlate digital imaging analysis and the volume or size of a ball mark. A golf ball was slowly depressed deeper and deeper into a clay block so measurements and photographs could be obtained at various depths. The clay was a brown/red color, so the macro normally used for ball lie measurements was counting the clay as red pixels.

In order to not count the clay, we had to adjust the hue and saturation description within the software. To adjust numbers and determine the correct settings for different pictures:

1. Open an image in SigmaScan.

2. Under the image menu button, click on...

3. When the color range appears, you can move the rectangle to various portions of the box to change the hue (actual color in spectrum) and saturation (brightness/dullness of color) setting.

4. Run those settings with the image to see what all the program is picking out with the given values.

5. When you get a setting that works well, write it down, and alter the settings in the macro.

6. Run the batch analysis and work with the data in the Excel file.

This was information I learned today while trying to analyze the photographs.