Monday, 20 June 2016

What shape is your grass?

Turfgrass management is a constant battle. Grass vs disease, grass vs weeds, and even grass vs grass. Sometimes it's obvious who is winning the battle but sometimes the victorious organism is less obvious.

This week while looking over some old pictures of the moss disease on my practice green (the moss is all gone by the way) I noticed something that I think could be useful for turf managers to quickly gauge which plant is winning and which is losing. Take a look at the following pic of poa taking over silvery thread moss with the help of some sort of fungi.

It looks very similar to the next picture with is Microdochium nivale totally destroying my approaches a few years back.

 And this picture of cyanobacteria thinning poa on my greens.

In all these cases the organism that is winning the battle has a round shape. In the first picture the grass is winning, and in the next two the grass is losing and the fungi/bacteria/algae are winning. Obviously if the conditions are favorable for disease development the disease appears round. This is especially true for patch disease which grow in size.

So great, disease is round. Whoopdy doo.

Where this observation becomes useful is when you are managing one grass species over another or when you want to know if the grass, or a patch of clover is winning the fight. Instead of waiting years to find out we can use the shape of the plant growing on the ground to tell us who is winning. This way we can either keep our management practices the same, or make changes to see if we can alter the conditions to favor the desirable species more.

Another way of looking at it is to look at the border between the two competing organisms. The convex border is winning and the concave is losing.

Take the never-ending battle of poa vs bentgrass. It's really hard to tell just by looking at a turf stand which species is winning the battle. If you look at the shape of the grass on the green you can easily tell which plant is spreading and which plant is being grown over.

The following picture is of my 8th green which is a mixed stand of poa and bent. As you can see the darker bentgrass is in round shaped patches and the poa is not in any clearly defined shape.

Here's a pic of my 4th green from 2011 with small patches of bentgrass just starting to take hold. They are round too. This was taken when I first noticed bentgrass making a comeback on my greens and was one of my first blog posts ever. This was what inspired me to start overseeding bent into my greens. If the bentgrass was doing good I wanted it to be everywhere in case my poa really started to die.

Here is bentgrass taking over on my 5th green. Notice the shape of the edges of the bentgrass patches. A quick glance shows that the bentgrass is clearly winning this fight. And they said you couldn't grow bentgrass on the Coast....

So this is probably no news to you. Way to state the obvious Jason! But I had never thought of this simple and probably very obvious observation in this way and I think that it will really help me easily and quickly evaluate my practices in the future when it comes seeing which organism is winning the battle.

Saturday, 18 June 2016

Moss Disease Revisited

This week on twitter I saw an interesting tweet.

This triggered my memory of the moss disease I had on my greens a few years ago. I wrote about that in a post in 2013. The reason I hadn't thought much about this interesting moss disease was that for the most part the moss on my greens is gone.

What did I spray?

Well in 2012 I sprayed Kocide 2000. It worked but was pretty harsh on my turf and the moss quickly came back.

In 2014 I sprayed quicksilver but left my upper practice green unsprayed to see what would happen with the serious moss disease infestation. Also, this spray wasn't successful with most of the moss coming back shortly after my 3 successive applications.

In 2013 my upper practice green looked like this.

Today it looks like this and I have not sprayed anything on it between the pics in 2013 and today to try and kill the moss.

There is literally no moss on this green whatsoever.

So if I didn't spray anything, what happened?

The moss was diseased. Yes, even moss gets disease. You can see the brown moss in between the moss/grass interface.

It's almost like the grass is growing in as fast as whatever is killing the moss is spreading.

I've learned a lot about moss over the years. I have a hunch it is less tolerant to traffic than grass is and might not tolerate frequent mowing. I also use pin locations to target moss infestations with golfer traffic. This might be one positive side of those troublesome Adizero golf shoes! So I'm thinking, no, the moss is on the ridges on your greens not because it's dry, it's because you don't put any pin locations on the slopes so very little golfer traffic is focused on these parts of your greens. This year we've also rolled our greens 115 times and it's mid June...?

Triplex tire marks have less moss. Does traffic impact moss? It takes an extreme case to visualize.

Since the old days when moss was an almost constant problem on my greens I have completely changed the way I fertilize my greens. Where I used to withhold nitrogen in August (when moss seems to really take over at my location) I now apply the majority of my nitrogen fertilizer in the Summer. This is based off the growth potential model and has been universally positive for my operation. Not only that, but it has also allowed me to cut my annual fertilizer rates in half and still see improvements in turfgrass quality.

Change of mindset

Since 2014 I have basically ignored moss everywhere on my course. My limited success with Quicksilver and relative reluctance to use a herbicide on my greens left me without much in the way of chemical controls. I also changed the way I thought about weeds and started focusing on the desirable species instead of the pest. So far this has worked out great! It's not just a pipedream haha. Basically I've really focused on grass plant health and it has paid off. Forget the moss, grow good grass!

Less Fungicide

If the pathogen that was killing the moss was a fungi, then it is probably controlled by some of the broad spectrum fungicides we use on turf to control turf fungal pests. Over the years I've made some progress to reduce the fungicide use on my course. For some reasons (I have no clue why) the upper putting green requires almost no fungicide. Maybe this is why the moss disease was allowed to go crazy on the moss?

So there you have it. I kind of hate how hippy dippy this all seems. "Change the way your fertilize, use less fungicide, roll more maaaan, let nature do the work." It really does sound a bit idealistic for my liking but what can I say?

Sunday, 12 June 2016

Do you even IPM?

Integrated Pest Management (IPM) isn't a new concept. It might actually be one of the oldest ways turf managers have dealt with certain pests, but in recent times we have been able to rely less and less on IPM practices as amazing new pest control products come to market. These new products essentially allow us to do almost anything to our grass regardless of what the pest pressure is.

Integrated pest management (IPM), also known as integrated pest control (IPC) is a broad-based approach that integrates practices for economic control of pests. IPM aims to suppress pest populations below the economic injury level (EIL) Source: Wikipedia

Now even with these highly effective pest control products we still need to use IPM to some extent to help get through periods of extreme disease pressure. Raising the heights of cut, water management, and fertilizer practices can all help when used in conjunction with effective pest control products. There's no product that will allow you to do anything to grass with no consequences but with a broad IPM plan you can possibly get by with cheaper products and products that have a lower environmental impact. With good IPM we can also reduce the need for preventative pesticide applications and can stretch our pesticide application intervals. This is key to be able to see the benefits of IPM on your golf course.

There's no point in IPM unless you can keep the grass healthy and playable
I often share some of the practices that I have found to work for me but get the response that it doesn't give good enough control to keep pests below the EIL. Of course every site is different but I also question the use of IPM practices if they don't make a measurable difference.

For example, I used to drag dew off the greens in the winter to "reduce disease pressure" of fusarium. It turns out that dew (or rain) has very little to do with how bad fusarium is in the winter in my part of the world. I wasn't seeing any impact from this time consuming practice so I dropped it. I made a change and I saved time and money.

Another example was how we used to water greens last each night to reduce the period of leaf wetness in an effort to reduce disease. Again, I saw no real impact on disease so switched to watering greens first thing each night which made it much easier for me to manage poa greens during stressful drought conditions. I made a change and conditions improved.

ISR products like Civitas and phosphite will also leave you disappointed if you use them like traditional pesticides. You will see the maximum benefit of these products if you use them in conjunction with good and broad IPM practices.

So if you employ IPM practices you need to ask yourself a few things. Does it increase the quality of my playing surfaces? Does it reduce the need for corrective or preventative pesticide applications? If it doesn't, the IPM product or practice you are using is probably a waste of time and money.

Rolling and hand watering are very important parts of my IPM plan
It's no secret that I have had a lot of success this winter/spring managing fusarium. I continue to be surprised each and every day at how little disease there is on my putting greens. No matter what the weather throws at us they continue to be disease free for some reason. I was recently asked why we had so little disease this year. Of course, a lot of it is probably luck. For some reason I have been able to make decisions that are correct over and over. This doesn't happen very often especially when dealing with nature!

This day saw temperatures reach 37C! That's hot for our poa but it managed just fine.
The other reason is that every single aspect of my maintenance plan revolves around disease management. From mowing, rolling, fertilizer rates and types, irrigation, plant growth regulators, traditional pesticides and ISR products. As fusarium is our most costly and potentially damaging turf pest we throw everything we have at it to try and lessen its impact on our operation. We don't just employ the odd practice here and there, every single thing is geared towards fusarium reduction while still maintaining quality playing surfaces for golf.

Since changing to this approach we have been able to make huge reductions in costs and environmental impact and huge increases in turfgrass quality. Now that's what I call IPM!

In an upcoming post I will share in detail my approach to managing fusarium patch at my course.