Thursday, 23 February 2017

More sand with solid tine aeration?

I came across this on twitter this morning.

And then this rely:

This got me thinking about what I have noticed on my course. For the past few years we haven't been pulling a core and I also noticed that we were able to get about 30% more sand into our greens at aeration time but never really though much of it as it relates to solid vs core aeration.

I think that when we core, it is difficult to get the entire plug removed. This leaves some of the holes still partially filled with soil/sand and reduces the amount of sand we can get into the hole. Getting a good core is dependant on a lot of factors. Getting a good tine penetration is dependent on a lot less.

When we solid tine, we get a more consistent depth because we are not leaving behind any material, we are simply smashing the tine in and spreading the soil apart. We can then get a more reliable hole depth, and therefore, more sand into our profile.

Wednesday, 22 February 2017

Recovering from winter damage with GP and MLSN

You might have heard that my course has suffered some winter kill and I'm sure some of you have some questions about why this happened relating to GP and the MLSN as well as how I plan on recovering from it using the GP and MLSN.

So is my dead grass a result of the MLSN or GP?

If I was the only course to have winter damage I might think so. Even so, I do talk about some pretty extreme practices that could lead to winter death of my grass.

Is winter use of primo the reason my grass died? Probably not

I have talked about how I limit potassium going into winter as inspired by this research.


While this is interesting stuff and something that I am trying, Doug and others have made it clear that by limiting potassium during the fall can decrease the winter hardiness of poa annua. Poa annua is the predominant grass species on my putting greens so obviously it would be a bad idea to limit K during the fall as this would lead to bad things happening.
Low K hasn't hurt the poa on this sunny green. Last fungicide was late September and it's still virtually clean after 6 weeks of snow cover.
So while I have been playing around with limiting my potassium in the fall, it is only on greens that have a mixed stand of bentgrass and poa, and on greens that typically never see damage in the winter months. The greens that have a history of damage, received potassium fertilizer with every application last fall in order to hopefully reduce the chances of winter death. Even with this supplemental potassium fertilizer last fall, the greens died.

As we all know, sometimes no matter what we do, mother nature wins and our grass loses. As described in my post to my membership, the real issue on the damaged greens is shade.

This green sees little sun during the winter
Greens that receive adequate sun have no problems even though they endured the same freeze thaw and ice events as the other greens. The shade also makes the ice issues worse on the already weakened grass. While there is no way for me to determine if the damage was made worse by the way I fertilize my grass, I highly doubt it as the grass that receives enough sunlight is in the best condition I have ever seen it despite not receiving fall potassium.

Adequate sun, good grass, and no potassium in the fall.

So no, I don't think the MLSN or GP had anything to do with my winter damage on my course. There are other courses in the area that fertilize differently and they also saw damage on their greens, again, in shaded areas.

So what about recovery? Well this isn't the first time I will have to recover my greens while using the GP and MLSN. The first winter after I adopted the MLSN and GP my greens also suffered similar hardships. At this time I was seriously questioning the MLSN and GP but decided that the science still made sense to me and that I would stick with it. In the end, the greens recovered nicely and I continued to use the MLSN and GP to fertilize my grass.

So what did I do the last time and what am I going to do this time? One of the great things about social media and the internet is the ability to share what works and what doesn't work. I know what I did last time and it worked and I have talked with many others about what they have tried for recovery in the spring. One thing that particularly stuck with me was a conversation with Bill Kreuser about his research done on methods to accelerate winter recovery. Basically, no matter what they tried, be it increased fertilizer or various covers, "it becomes increasingly apparent that timing of spring seeding and air temperatures following seeding are fundamental factors affecting the success of re-establishing putting greens." While this is only one study, I would agree based on my previous experience recovering from winter damage.

The last time I had winter damage I used the growth potential as a guide, but increased rates to hopefully get increased recovery. I more or less applied double the fertilizer that the growth potential recommended. For the first 4 months of 2013, that amounted to just over 1g nitrogen/m2 (~0.25#/1000). This was still well below the rates that I used to apply nitrogen during that time of the year.

I had some good growth rate data and knew when I could expect the grass to grow. I also knew that pushing growth when it was cold was a waste of time and would only cause issues when it finally warmed up. I was patient and by May 1st the greens were back in good condition.

What about the MLSN?

I don't have the luxury of soil testing often or in many spots each year due to cost so I took what I knew and used to ensure that my grass had the nutrients that it needed. I decided to play it safe as I couldn't do a test at that time and applied the fertilizer in a ratio that was found in the plan. This would result in some minor over application of some nutrients that I already had in my soil, but when I finally did do a soil test in June, I would be able to adjust and make up the savings at that time.

That's the thing about MLSN. It is simple and allows me to make some assumptions to get me through periods of unknowns until I can again do a soil test. I applied slightly higher amounts of K and P and Ca than I would normally apply, but at the end of the year I was right back on track with applying only what the plant could use.

This year I don't plan on doing anything different.

I applied a light application of a granular slow release fertilizer blend that I had lying around (first granular fertilizer on greens since 2013), and will continue my regular fertilizer program of liquid fertilizer applications that are light and frequent. I will again soil test this Spring and will make adjustments to my nutrient quantities at that time to limit any waste.

I have also decided to use this opportunity to get some more bentgrass established on my greens. The last time we had winter damage I threw down some bentgrass seed and it filled in nicely. Those areas today are still damaged, but playable as there is enough bentgrass to fill in the voids left by the dead poa.
bentgrass seeded in when greens were damaged in 2013

I am also doing tests to see if I can use winter play on frosty greens to selectively kill poa annua from my greens with bentgrass. Stay tuned for the results of that!

Tuesday, 14 February 2017

Dollar Spot IPM

Ok, so this is going to be a long one, but if you struggle with dollar spot and want to maybe reduce its impact on your grass and budget I promise it will be worth your time.

Last week while at the 2017 Golf Industry Show I was a presenter at a panel discussion called "Successful Low-input Turf Management: Is it practical?" One of the things I discussed was how the growth potential formula got my nitrogen rates on track and helped reduce the impact that dollar spot had on my course. After this talk and my release of the slides on my blog (linked above) I had a few people reach out with their similar dollar spot success. Of course I asked to see their fertilizer records and by no surprise to me, during times of typical dollar spot disease pressure, they were applying their highest rates of nitrogen (among other things).

During my presentation on the growth potential and the MLSN I urged participants to take their growth potential nitrogen use recommendations and compare it to what they were currently doing on their course. I outlined the importance of proper amounts of nitrogen on dollar spot (which is the most costly disease to control in N.American golf) and asked them to see if maybe the growth potential model would recommend a nitrogen rate that would reduce the impact of this costly and devastating disease.

dollarspot tweet.pngOne of my favorite tweets of 2016 was this on the left. It clearly shows the impact nitrogen has on dollar spot. Note the date of this tweet, mid September. I don't know about you, but that is when my course gets absolutely destroyed with dollar spot and it looks like the other plots are also getting hit pretty bad.

At 5.4gN/m2/month (1.2lbs/1000 sq ft) I don't know many people that would use that high of a rate. The growth potential formula recommends a maximum monthly nitrogen rate of about 3gN/m2 (0.7lbs N/1000 sq ft).

If we apply the grammar of greenkeeping to these rates they suggest that they are applying a log% of 94% more than the growth potential for Madison Wisconsin in September.

The great thing about this blog, and social media is that you can throw out an idea and inspire others to reach out and share their experiences with you. This is exactly what happened last week. A superintendent from the Toronto area reached out saying that he had "no Dollar Spot on fairways where other clubs in the area struggle with the disease." Included with the email was his fertilizer records for fairways. I asked when they typically had the worst dollar spot and the answer was September just like it is for me.

Here are the nitrogen rates. One thing jumps out at me, the increased nitrogen rate for September.

No Dollar spot Toronto N g/m2

But I want to know how that relates to the growth potential for that specific climate and how much he is deviating from it. Again using the grammar of greenkeeping.

average Temp TorontoGrowth PotentialGP fert g/m2No DS Toronto N g/m2Log %

If you look at the last column you will see how far he deviates from growth potential. Wow, way over in September which is the time that they typically have the worst disease and actually lower during the rest of the year.  I wonder if he was applying nitrogen closer to the gp all summer long if he could use less nitrogen in September and maybe avoid the negative consequences of such a high nitrogen rate such as increased growth and mowing?

While the study in Madison was at 94% over the GP, the super in Toronto only needed 60% over to get success.



Our golf courses aren't science experiments which often set out to measure the impact of one variable on a plot of grass. We have many variables that we can throw at this bastard disease and when it comes to IPM, I highly suggest you throw as many variables as you can to get the best results :) This reliance on only one variable is a big problem and something will address in an upcoming blog series.

What the hell else do we know about dollar spot?

I know that it hates rolling and guess what? I love rolling. So maybe the growth potential formula combined with rolling will give you the results you need?
I love rolling
It also doesn't like ferrous sulfate as was outlined in this study. And guess what the super in Toronto was doing?

No Dollar spot Toronto N g/m2No Dollar Spot Toronto Fe g/m2

He uses iron too (more per month than I use per year). So he is hitting dollar spot with multiple variables! How do those rates compare to growth potential? I don't have to do the math that they are astronomically higher than what the GP and MLSN would suggest. My soils have about 269ppm of iron which turns out to be about a 500 year supply!

In this case he is using iron not for plant nutrition, but for pest control. Be careful, at the high iron rates in the referenced study above, it reduced turfgrass quality. Here's another article about iron and dollar spot.

Last September I required the first synthetic pesticide application for dollar spot in a long time. If I was rolling and using the growth potential why did dollar spot get out of hand?
After the fungicide, pressure was high!

Well there's the possibility that that the golf gods were tired of my arrogance or maybe it is because I was applying less nitrogen than the growth potential formula recommended instead of a log% of 94% or 60% more.  I had some theories last fall about why but it probably had to do with luck and nitrogen rates. I simply wasn't applying enough because I forgot about dollar spot after a few years of success and was pushing my luck in the name of fast greens for an important upcoming tournament that you definitely shouldn't aerate the week before (like someone else did a few years back).

I also wasn't applying as much iron as I had in the past. Maybe that's why? Next year I will continue light iron apps through the summer as in previous years to try and get me through without a pesticide application.

I get twitchy about nitrogen in September because of fusarium on my greens. Generally, high nitrogen makes this disease worse so I start cutting back big time in late Summer. I had been seeing the disease all summer and probably should have pushed my nitrogen rates a bit higher in the summer to reduce the disease buildup so that I could reduce the rates in the late summer when I got hammered (with disease not like in the picture below).

So this is another example from another course that isn't mine in an area that probably gets way worse dollar spot as some would have me believe, but trust me, we get dollar spot here too.
 dollar spot isn't just for you grass killers on the East Coast.
dollar spot.jpg
To push this a bit further I want to understand why these high nitrogen rates are reducing the severity of the dollar spot. Is it the nitrogen directly? Is it simply the plant outgrowing the damage caused by the disease? Or does it have something to do with the biology in the soil or a combination of all three? While I have no direct evidence myself, I do have some educated guesses as to why these high nitrogen rates are impacting this disease and this could better help turf managers reduce the impacts of this troublesome disease if the high nitrogen rates simply aren't enough to keep the disease under control.

Personally, I think it's the biology but don't worry, it's not in a vague hippy dippy sort of way.

The first time I learned about how the soil biology might impact dollar spot was in a rolling study by Dr. Thom Nokolai. In the study which showed that rolling had a significant impact on dollar spot, they found that there were also elevated levels of  bacteria and actinomycetes in the soil. Go to 5:00 in the following video for his explanation.

So elevated bacteria might mean more competition with the fungi which are responsible for most of the disease that cause turf damage including dollar spot.

Last summer I came across something interesting in a disease update where they say "There is evidence that hydrogen dioxide can aggravate a dollar spot outbreak by reducing natural competitors to the Sclerotinia homoeocarpa mycelium." This was hammered home last week as I sat in on the "Turfgrass Talkshow" at the Golf Industry Show where Thom interviewed David Bataller who is the superintendent for the PGA Catalunya Resort in Spain. In his interview he explained how he used hydrogen peroxide to dissolve soil organic matter on his greens. (yes, you heard that right, I highly suggest you look into this because it's awesome). David explained that there was virtually no negative impacts except "it made dollar spot worse."

I wasn't surprised to hear that and was actually expecting it based on what I already thought which was that hydrogen peroxide was also vaporizing the soil bacteria ( and insects and and and...) which gave the upper hand to the dollar spot fungi. Again, I'm just putting two and two together here, I haven't seen any data on this.

Ok so if soil bacteria and in particular, higher levels of bacteria, are important to dollar spot reduction, why is applying relatively high amounts of nitrogen reducing this disease? Because no matter what some will have you believe, "the overall effect of fertilizer applications is to markedly increase microbial numbers and activity in soil through increased plant growth." No, we probably don't need to add biology directly to the soil, we can do it indirectly and I would argue, more naturally!

So no, my "salty" fertilizer isn't killing the soil.

Am I right about this? Probably, but sadly there is no proof of it that I am aware of for my specific situation ;)

There are things out there that on their own will control dollar spot. Costly fungicide, nitrogen that will lead to increased growth, or iron that can burn the grass. The important thing is to know how each of these things can impact the disease and be sure to use them together to get the desired results.

So if you have trouble with dollar spot or are facing increased environmental restrictions for pesticide use (like they are in Europe) or simply cannot afford pesticides and would like better grass, I would make the following recommendations to reduce the impact of dollar spot on your course:

  1. Know what the growth potential is for your site and ensure that you don't limit nitrogen use during periods of high disease pressure. Be open to applying up to 1.5-2x the GP if conditions require but also be aware of the consequences of this (more growth, more mowing, likely more fusarium).
  2. Take a multi pronged approach, look into iron sulfate and rolling but again, also understand the impacts that these will have on your grass.
  3. Avoid things that will impact soil bacteria negatively. What is that? I don't know but I probably wouldn't use hydrogen peroxide.
Is there more to this that I think? Most certainly. It will require a balancing act and some finesse and lots of observation and reflection but either way, I bet it will result in a substantial savings or increased turf quality with little negative impacts on play.

And hey, more microbes ;)

Thanks to everyone who has reached out to me in the past. It helps me learn new things and refine my strategy so that I can share it with everyone here.

Wednesday, 8 February 2017

GIS Job Board Presentation

Today I did a presentation on Job Boards on the trade show floor at GIS. While there are many good paid versions, the free home-made versions can offer a lot of features that even the paid versions can't. Even if you still feel like the paid versions are best, I hope this presentation will help you look for features that matter to your operation and result in increased productivity instead of a needlessly complicated solution to a simple problem.

Here's a link to my job board so that you can make a copy and try it out for yourself.

For a list of all my job board related posts click this link.

And check out my presentation below.

Monday, 6 February 2017

How reduced fertilizer has benefited my golf course.

Today I was honored to be a part of the EIFG panel discussion at the Golf Industry Show. My presentation was about how reduced fertilizer has benefited my golf course as I have implemented the MLSN soil guidelines and used the growth potential formula.

Obviously the biggest impact of using less fertilizer is that you spend less money buying fertilizer. This is just the tip of the iceberg though. I have seen impacts such as less weeds, disease and fuel use. When I think of it, there have actually been no negative impacts.

Check it out below.