View Full Version : Need help on Dollar Spot

Quail Creek LC
07-18-2004, 07:31 PM
Guys, I have a few yards that are starting to get dollar spot. We have been real wet here all summer. Now the heat is starting to come up along with the humidity. Yes I am a certified commercial applicator and this is my first year. What do most of you do for dollar spot? Any help would be great. Just to let you know, the lawn has not been irragated this year and is just now starting to show stess of low moisture. Sould I have them turn the sprinker system on? Will this promote more of the fungus to grow, or will it help out. I also heard it could be lacking Nitrogen. Should I fert again. Thanks in advance.

07-18-2004, 08:15 PM
Try to encourage proper watering practices (water deeply and infrequently, only in the morning not the evening.) Fertilize to encourage growth. Minimize turf stress.

07-18-2004, 10:16 PM
Dollar spot tells you, as the observer, that the yard is experiencing a N deficiency...

Quail Creek LC
07-18-2004, 11:19 PM
I've also read some things that say that it is to high in Nitrogen and some say that I may be lacking Nitrogen. All the research that I have done on this subject has gotten me confused. Thats why I'm asking you experienced guys, cause experience to me is what counts and not what you always read.

07-18-2004, 11:25 PM
Dollar spot can be worse in lawns low in nitrogen. You want to encourage growth at this point. It can be pretty unsightly but the lawn will recover.

07-19-2004, 08:00 AM
Fert with high content N content soluable fertilizer - then apply daconil weatherstik or a daconil equivilant. Snap that dollar spot out of the turf with-in three or four days. Deep, infrequent watering is better than no watering at all - so turn on the irrigation system

07-19-2004, 10:59 AM
SWD, he's a new guy. He doesn't any old jugs of non-restricted Daconil like you and I, LOL.

Quail, I assume this is residential. Over the last several years the number of fungicides you can use on home lawns has been dramatically reduced. Besides, the general recommendation for residential turf with DS is to improve cultural practices (Esp. irrigation timing and fertilization), not to apply fungicides. I have had only one occasion in last 5 years where a fungicide was used, and that was a lawn not on a fert program, hammered by DS (on river, in late July), and had to look good within 3 weeks. Don't panic about a little DS, you can find it in every lawn once you know how to look.

Here's an educator's discussion of turf diseases: http://www.btny.purdue.edu/Pubs/#turf . There is a dollar spot bulletin there, along with most other diseases you will encounter.

07-19-2004, 03:29 PM
Good advise groundkprs

I think we in lc get too excited about disease on residential turf! If properly fert, and following the rest of the correct culture pratices, disease shouldn't be a problem! I'm not saying you won't have any, but not severe enough for treatment!

Generally dollars spot is more of a problem on turf seeking nitrogen!

Quail Creek LC
07-19-2004, 03:37 PM
Thanks for all the info guys. The lawn is not in to bad of shape, it just makes me a little nervous! I'm new and still learning. I'm doing this all on my own and have nobody to look to for advise. I've been just mowing for the last 10 years and just now started to get into the fert/chem aspect of it. I'll hit it with some N and hit the water hard and see if it comes out of it.

07-19-2004, 05:23 PM
a much bigger factor in disease activity over fertility is temps. and dampness.

when i was at URI (university of RI) studing turf management (ok, i didnt study much) but anyway we were taught how activity like dollor spot and red thread were due to poor fertility, more specificly lack of N.

20 years ago when i stated working at chemlawn we were applying 5 lbs N per season on a four step program. and seen the typical amount of disease activity. (thats a lot of N...yes?)

we now apply 5 lbs N to many lawns per season and the dollor spot- red thread activity is there.(still getting more N than a lawn generally needs)

ever notice how lawns with .automatic irrigation systems generally have the most disease activity? Most systems are not used properly. Then we have to account for the air temps.

Now I agree with something like dollor spot a supplimental feeding and proper watering will grow it out. I'm just saying the text books teaching of lack of N....i donno, not in my 20+ years of experience

07-19-2004, 06:21 PM
So a lawn gets 5 lbs of n/m per season, but if most of it is quick release, then the turf may still be hurting for n, especially in summer, because most of n should beavailablefor fall, and some what winter months of the year for cool season turf!

07-19-2004, 06:43 PM
timturf, i just stated facts as i have experienced them over 20 years.

I realize that many on this site feel they know more than everyone else. This may or maynot be the case here (in regards to your response to my experience) and quite frankly i really dont care.

I mentioned 5 # N....but never mentioned the source of that N (oh, I did mention Chemlawn, so that may be where you figured all quick release, but back then chemlawn was using LTRN (liquid timed release N) very slow as a matter o fact)

we never apply any fert with less than 40 % so called slow release. lawn disease, like dollor spot, is still active when the air temps are favorable and moisture are favorable. Both temps and moisture (whether from nature or man ie improper watering) are a bigger player in disease activity.

No reason to argue the point, the point is valid.

07-20-2004, 07:42 AM
There are several over the counter fungicides that would work for quail creek.
As far as not applying vs applying - when I have a customer absolutely demanding the best turf conditions possible and paying for it, I will apply a fungicide to augment my cultural program when needed.
My experience with university/extension circulars is that they are too general to be of any real assistance. Perhaps to a homeowner, at some base level.

Pilgrims' Pride
07-21-2004, 08:17 AM
Of course temperature and dampness are key factors in fungal problems.
Right on TSM!
Don't you guys notice exactly when these problems come up?
When temps are warmer and there is plenty of moisture and usually some humidity.
Fungal problems seem to always show up in the irrigated lawns.
Homeowners just seem to be experts and either over water or on the other end they "just sprinkle for about 15 minutes every day"
As far as fertility, I have seen dollar spot and red thread show up in both well fed and hungry turf.
But it's always when conditions are right.

As far as treating,
I think fungicides are a band-aid for a cut that isn't going to heal.
What I mean is why use a fungicide if the problem can and should be corrected by making some simple changes and advising the customer on what to expect?
Fungicides aren't cheap and until conditions change all we are doing for the most part is suppressing a problem until it runs its course.

My first approach is to feed the turf and advise the customer on proper watering.
I will also discuss the present weather conditions and explain how they can encourage these troubles.

Then, I will discuss fungicides and suggest that they be used as a last resort.

07-21-2004, 01:57 PM
TSM, I think you have very valid points, and I myself have seen these diseases show up on lawns regardless of fert. levels whenever the environment is right. My point was that by encouraging growth the lawn will recover faster once the conditions DS go away.

07-21-2004, 02:50 PM
Originally posted by turfsurfer
TSM, I think you have very valid points, and I myself have seen these diseases show up on lawns regardless of fert. levels whenever the environment is right. My point was that by encouraging growth the lawn will recover faster once the conditions DS go away.

understood, and agreed

Pilgrim also has points i agree with. fungicides are like taking asprin for a stressful headache. If you stay in a stressful mode you will need to take more asprin in 4-6hours. Apply a fungicide and if conditions persist (whether nature causes the conditions or the homeowner with poor watering practices) you will be back out there with more fungicides....very time consuming for an applicator and frustrating for the homeowner.

Generally the only time we apply fungicides is if we're looking at pythium (even then we might recommend letting it run its course then reseed) or something in the family of patch diseases.

07-21-2004, 09:51 PM
The problem with most applicators, and especially with clients, is when thet see a disease problem in turf, they immediately think of how to cure it NOW. If you are selling instantaneous gratification, haul out the fungicides and make some bucks.

But you can find dollar spot in practically every home lawn this time of year. Remember the disease triangle: a susceptable host, presence of the pathogen, and proper environmental conditions for the pathogen to become active. I have never seen a lawn in which I could not find some dollar spot this time of year. You cannot control the spread of pathogens or the environmental conditions, and all grasses are susceptable to some problems.

The real answer is cultural practices. By having a long-term healthy turf stand, you reduce the susceptability to visible damages. We had a bad winter for snow mold here. I expected ryegrass and bentgrass to show damages, and they did - a lot. But weak bluegrass lawns also were hammered - lawns that I am working on to recover from past poor cultural practices, mostly over-irrigation resulting in heavy thatch. Healthy bluegrass with long term good cultural care was hardly affected.

The same holds true for all diseases. If the turf is healthy - good rooting, no excess fert or irrig, soil not compacted, and numerous other cultural conditions we can control - the pest pressure (weeds, insects, diseases) will generally be slight on such properties.

James Cormier
07-21-2004, 10:58 PM
One thing I didnt see anyone say.....core aeration.....

Soprano's are on, I love HBO on demand....I give my 2 cents thursday...oh wait Ill be at the sox's double header.....friday morning then

07-22-2004, 02:32 AM
But, James, is aeration the answer to every lawn problem? It is a good answer for many lawns, but how dense and often do you aerate? Is one pass good enough - or is 2, 3, or 4 passes what this lawn needs? And is it aerated once a year - or twice, or 3 times? Are there lawns that just don't ever need aeration?

07-22-2004, 08:32 AM
Good post groundkprs

James Cormier
07-22-2004, 11:17 AM
Originally posted by GroundKprs
But, James, is aeration the answer to every lawn problem? It is a good answer for many lawns, but how dense and often do you aerate? Is one pass good enough - or is 2, 3, or 4 passes what this lawn needs? And is it aerated once a year - or twice, or 3 times? Are there lawns that just don't ever need aeration?

It may not be the "answer" to all lawn problems, but it very well maybe the answer to this problem.

There was a whole bunch of posts about, amount of N, fungi treatments & watering times but no one brought up aeration, and just how important it is to keeping many diseases from being a problem.

My biggest problem I face ( most calls to my office ) from current customers is red thread, by far majority of customers with this problem always say core aeration is too expensive, but then they don't care what a fungi treatment costs.

Because they type in red thread in google and it tells them to apply a fungi.

All my customers that are on a core aeration program as well as a fert program dont have this problem, or really dont have any disease problems, granted these are customers that dont care about costs and leave all turf related issues to me, so Im in control of all cultural practices.

07-23-2004, 09:36 AM
Dollar spot has been widespread in North Georgia this year. Even with lawns that are on scheduled fert programs, it has appeared. Almost every Bermuda lawn I mow has seen it lately.

We've had some extended wet periods where higher than normal rainfall at times has leached the nutrients at a faster rate. Couple that with cloudy and wet conditions, and the dollar spot takes off.

Adequate N combined with the hotter weather will generally be enough to cure the problem.

Core areation provides a more healthy turf overall, but I don't see the connection in how it could help resist dollar spot. The only cultural issue that prevents it is proper watering and adequate N.

07-23-2004, 10:46 AM
OK, James, aeration is a good cultural practice in many areas. I have a problem with the idea that it is necessary for a healthy lawn. If I understand your area, you are dealing with rather old soils, of fairly consistent makeup, so you can make a blanket statement like that. This may not be the case for someone else in a different part of the country. My soils are relatively new, being at the edge of the last glacial advance. I have seen one part of property all clay and another part pure sand in the glacial till areas. Go a few miles south and you're in pure clay in the outwash plains. Muck soils trucked in as topsoil in new construction cause individual headaches.

I aerate from never, up to 3 times a year, depending on what the particular lawn needs. I attack thatch buildup with twice annual, 4-pass aerations for 2-4 years - have actually salvaged a lawn with a 1-3/4 inch thatch layer that way. 100 miles SE of me, where they plant in pure clay, premium lawns are aerated 3-4 times a year.

People need to understand that turf looks like it does in the few inches above ground because of the environment underground. Aeration is a great correction for compaction, but it is just one cultural practice to enhance turf health and quality. Reducing compaction may not be what a particular lawn needs. There is a whole range of cultural controls we can use to benefit a given turf.

TurfU, you are wrong- irrig & fert are important in DS control, but are not the only things. Use of all cultural practices to enhance the overall health and vigor of a turf stand will increase that stand's resistence to all pests. Aeration is a good cultural tool, but far from the only one you need. Try it some time: aerate only half of a problem property over a 3-5 year period, and compare the turf vigor and pest activity on the two parts. And there is no cultural practice to PREVENT dollar spot - you are increasing resistance and recovery by your cultural practices.