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View Full Version : Grey Spot, WTF!?


Florida Gardener
11-18-2009, 12:43 AM
This has been out of control since September down here in S. Florida. My best account that had fresh sod laid in may and has been fertilized twice since then and has looked picture perfect and has also been sprayed by a spray company 2 weeks ago had a little patch with it while I was over the other day. I'm getting really tired of this disease!

greendoctor
11-18-2009, 01:56 AM
I once had a bad experience with gray leaf spot on st augustine. It was my fault on top of that. I was growing in a lawn from sprigs. It was being irrigated twice a day, in the shade. Weather conditions at that time were hot and humid. I also put down almost a lb of N from urea to try and hurry the grow in. Gray leaf spot. It did not go away until the lawn was sprayed with Insignia, followed by 3336, followed by Eagle EW. All at 14 day intervals. That lawn never had gray leaf spot again. Since that time, I fertilize that lawn with potassium nitrate and micronutrients. No more urea. I have no idea what your spray company is using, but if I had to guess it would be propiconazole, which is the cheapest fungicide and also the least effective against gray leaf spot. I also have to look hard at how common lawn fertilizers are all urea based.

Florida Gardener
11-18-2009, 08:21 AM
Green

The area of emergence is in full sun, and has been getting watered 2x/week. The weather has been high of 80-84 the past 2 weeks with very low humidity.
Not sure what my spray company is using, but another of my customer's that they take care of had a small emergence as well( one of the neighbors has it bad 2 doors down) and they came back to treat and it is completely gone.

txgrassguy
11-18-2009, 09:45 AM
How did you identify the Grey Leaf spot?
Through a soil sample or from the technicians diagnosis?
I ask as Helminthorsporium Leaf Spot may also be a factor.
Regardless both diseases are exasperated by excess N fertility levels and poor/compacted soil conditions.
Green offers a pretty good chemical control however I'd suggest an aggressive hollow core aerification with core clean up prior to additional control measures to alleviate the most common stressor to the site.
Micro-nutrients are the most commonly overlooked control to assure a healthy turf site - and when coupled with an aggressive aerification and raking program wherein extensive bagging of clippings occur essentially all the stressors common to St. Augustine can be eliminated.
Doesn't do well for the spray company profits though.

Florida Gardener
11-18-2009, 10:39 AM
By what the company told me and the signs matched the UF literature......Chlorotic patches of St. Augustine throughout the yard. Is the other disease similar to grey spot??

This new sod was put down in May. My Lesco guy told me to fertilize after the 1st 6 weeks and then again 6 weeks from that point with the 15-0-15 dialed back a few notches(#16 instead of #19). The lawn looked PERFECT. It still does, except what appears to be grey spot popped up about a week ago. The company sprayed on the 4th and they are going back this week to control the disease. I just hit it with the 15-0-15 this week at the #16 setting. This isn't too much N, is it??

All I know is this has been popping up everywhere the past 2 months down here. We haven't had steady rain since August either. In fact, since September, it has been pretty dry.

txgrassguy
11-18-2009, 05:33 PM
First of all have you calibrated your spreader - those number settings are meant to be a starting point. Walking speed, variances in spreaders and material will all cause a difference between the set points and what is actually happening.
From what you are saying about the amount of fert, what is the formulation and source of the Nitrogen?
Stressed turf, including newly laid sod, should be fertilized very judiciously. Also without seeing the coverage of the irrigation system the salts in synthetic urea can easily stress the turf even beyond what Obama is doing to our economy.
A good tip is to use the activated bio-sludge fertilizers like Milorginite when applying fert to new turf. No salts, a great ash content once the material breaks down and it is almost impossible to over apply - plus this stuff is great for microbial populations.

ted putnam
11-19-2009, 12:04 AM
Especially when environmental factors, whatever they might be are cause for increased possibility of disease, you have to get out of the mindset that you are there to apply fert because its been 6 weeks. You are there to do what's best for the lawn at that time. Applying standard fert to St Aug that has much leaf spot in it at all is like throwing gasoline on a fire if those environmental factors persist. Some you can control, some you can't. Make sure the fire is completely out so you aren't just fanning the flames.

Florida Gardener
11-19-2009, 12:22 AM
I'm not just fertilizing b/c it has been 6 weeks. The lawn has been perfect(and still is) minus the very small area of the fungus. My Lesco dealer told me that the sod needs to root in and establish itself those first three months and that the 15-0-15 would help it do so. He told me to not apply as I normally would and to dial the spreader setting back. His recommendations worked GREAT. It has been 3 months since I last fertilized and gave the lawn a round before winter to go until early spring. Even on this round I dialed the spreader to the setting it has been for the first two apps.

ted putnam
11-19-2009, 08:37 AM
I'm not just fertilizing b/c it has been 6 weeks. The lawn has been perfect(and still is) minus the very small area of the fungus. My Lesco dealer told me that the sod needs to root in and establish itself those first three months and that the 15-0-15 would help it do so. He told me to not apply as I normally would and to dial the spreader setting back. His recommendations worked GREAT. It has been 3 months since I last fertilized and gave the lawn a round before winter to go until early spring. Even on this round I dialed the spreader to the setting it has been for the first two apps.

Sorry, I misread. If you are fertilizing and another company is spraying( which to me is recipe for disaster) your schedules need to jive or it can end up being a case of a dog chasing his tail. As far as rates. Like someone else said, calibration is the key. Numbers are merely a reference point. I'm not sure if Daconil is still available but it is a great fungicide for solving the leaf spot problem. Good Luck

txgrassguy
11-19-2009, 09:14 AM
Not to beat a dead horse but those spreader settings are there to assist in calibrating to ensure accurate applications.
In the future I'd suggest pulling a soil sample first to acquire the recommended inputs and apply accordingly.
High levels of quickly available salt based N sources on stressed St. Augustine is a sure recipe for pathogen problems.
Especially when one considers how slow St. Augustine is to recover from injury.
Catch cans are available for the Lesco spreader to aid in calibration or you can use what my crews do - a 7 mil thick garbage bag. It sure isn't pretty but it works.

Florida Gardener
11-19-2009, 09:14 AM
No problem Ted.

I really want to get licensed so I can spray. This company told me they have helped people get licensed before(it's a mom/pop company) and I am hoping they will do the same for me. I am in contact with them as far as the properties that are mine that they service so I know when they are going and if I am about to fertilize and there is an issue on the lawn I discuss with them to see if everything is fine for me to do so.

Florida Gardener
11-19-2009, 09:48 AM
txgrass

Can you explain to me what the settings mean then?? I have a Lesco rotary. For example, what does #16 actual mean??

The grass is not stressed at all from what I know. I have been cutting it at 4"
all summer and it has been looking beautiful. Yes, there has been some broadleaf emergence, but the spray company has been taking care of that. Since the sod was laid down in May, this has been the first spotting of fungus. We had a very hot, humid, and wet summer as well.

Landscape Poet
11-19-2009, 10:08 AM
Diamond - I noticed you said when you said you were laying new turf, Lesco rep told you to use 15-0-15 to help establish roots? May i suggest this product SULPO MAG (http://www.lesco.com/NoCompression/GetData.aspx?Type=ProdResource&ID=3343&.pdf).

I think you will find this product is a better alternative to establishing St. Augustine in areas or during times/conditions in which fungus could result. With 10% Magnesium - it will help do the job and is a element which has been shown to help prevent fungus. Now this will not give you the green you are going to get with the N products, so if you are seeking that Green, I would suggest putting down Tech Mag along with the the sulpo mag. Here (http://www.lesco.com/NoCompression/GetData.aspx?Type=ProdResource&ID=2910&.pdf) is link.


As far as the fungus - it has been a hell of a year for it. My first bought was in Feb this year and it has continued to show its face all the way up until last week. With their being well over 350 different types of fungus, it is hard to perform a correct diagnosis without lab result. I use Armada a majority of the time for treatment. It seems to have performed best for me, so this may be something you may want to look at.


I feel that the two applications above are about as safe and will give your new turf, even existing, a great dose of nutrients, without the potential of creating a excess amount of N in the soil, thus sparking a fungus outbreak?
How does everybody else feel different about this?

txgrassguy
11-19-2009, 04:37 PM
The settings on the Lesco rotary spreader are a guide to use when utilizing granular materials of a constant prill size. Pretty much a Lesco 15-5-10 with 10%Fe requires a number 15 IF you walk a certain speed, overlap a specific distance and can maintain it for the duration of the application.
Remember though that ground speed varies, prill size is not always constant for a number of reasons, and not every spreader is the same.
So, once you know what your application rate is supposed to be and you have the granular material to apply, simply calibrate your spreader accordingly.
Who knows that number 15 setting might actually be a 10 or an 18 resulting in under or over applications.
Don't sweat it as once you gain the experience, calibration is easy and teaches you to pay attention to the different granular materials and their respective prill sizes.

Florida Gardener
11-19-2009, 04:41 PM
Mike-Thanks for the info. The sod has been doing awesome and still is. Just a small outbreak of the fungus. I will look into those products for the future.

Tx-Can you explain that to me in lamen's terms please?

olive123
11-19-2009, 04:57 PM
i am not convinced you are dealing with grey leaf spot. I think they are misdiagnosing your problem. Could you send a pic? "Chlorotic patches" doesnt sound like GLS to me.
There is leaf spotting and scorching, not chlorosis.

Stress I find is one of the biggest factors. What cultivar of st. Aug is it. That is probabally the biggest puzzle piece.
In Sfla we are STILL battling chinch bugs. Its been a tough year. If you have been getting GLS over and over again there is something wrong. A couple treatments with thiophanate-methyl should control it.
Never over nitrify or over water. 15-0-15 is a good choice (i like to use 13-3-13)make sure you hit it before next summer with 9-2-24. This will help develop a health root system for the rigors of a long hot summer.

Florida Gardener
11-19-2009, 05:16 PM
Olive

I will get a pic tomorrow. They didn't say GLS, I am. I could be wrong, but it looks like the UF description.

It is Floratam. The "fungus" hasn't been persistent, it just popped up about a week ago.

The 15-0-15 has worked great thus far. It is plenty of N and has the 1:1 N/K ratio. In some of my yards I started to use the 8-2-12-4 Palm Fert. as recommended by Broschat and Elliot(The Palm guru's at UF). I went to the 2 day Palm seminar about a month ago and they said to use this all around for yards where there are palms either not in landscaping beds or where the palms are in beds right near the turf. Brochat said that K is always battling N and a palm with K def. needs more K than N. Adding either the 1:1 or something with greater N than K will further induce the def. They said the 8-2-12-4 is the best to use due to the right amount and type of micros and it doesn't have too much of one nutrient in relation to the others. Too much K and not enough Mg will cause a Mg def. Fe and Mn battle each other as well. That class was well worth $300.

Sorry to get off topic guys. I really appreciate everyone's willingness to help. Some guys on this site raise their nose to people.

Landscape Poet
11-19-2009, 06:09 PM
In Sfla we are STILL battling chinch bugs. Its been a tough year.

Still here in Central FL too, just had a customer that did not want to invest in protection loose roughly 8000 square feet in their backyard.
I really could not blame them as they bought their house at the end of September and the lawn had been treated by builder right before they bought with Bifen XTS. In Mid October they got nailed. Needless to say I think after getting the sod estimate, they are feeling that it would of been a wise investment.

olive123
11-19-2009, 06:50 PM
i was at the seminar too. Best I have ever been to. I would guess something else is going on in that yard

Florida Gardener
11-19-2009, 11:04 PM
olive, what's your name?

Landscape Poet
11-20-2009, 01:13 AM
I agree with Palm Fertilizer - it is one of the few INEXPENSIVE fertilizers out there. It is funny how this guys who make it can add micro's but all to often "Quality" fertilizer from Lesco does not have Micros in it.
Diamond - and well for that fact all other FL guys - I suggest checking out HOWARDS FERTILIZER here in Orlando. The make blends which usually contain a good blend of micro's in every batch and are not real high in N. They make quality fertilizer - well some - they make some Sh*tty ones two like everyone else, but some have really good blends with no fillers - they replace fill room with Micros.
Another alternative, if you are a Lesco guy, is to use Iron Plus from Lesco. A little more expensive but if you want a really GREEN yard, this is a good choice. With the amount of Iron in it though - I would suggest one annual application, not more, just enough to get a good mix of micro's in with your regular feedings. Here you go click on this IRONPLUS http://www.lesco.com/NoCompression/GetData.aspx?Type=ProdResource&ID=6375&.pdf

RMA
11-20-2009, 12:19 PM
New to this site and very happy ive found it!!!!!!! I also spray lawns on the west coast of Florida.. Ive had my dealings of gray leaf spot, seems to be everywere some lawns worse then other.. To put my 2 cents in, #1 cause of fungus is duel mower Blades, be sure whoever is mowing they are keeping shape blades on your turf. NEVER!! apply nitrogen while Gray leaf or any fungus is present all you will do is spread the fungus rapidly. Ive had great results with the chemical EAGLE, apply to dry turf and do not water in!!! 2 treatments 2 weeks apart.. Apply only your pesticides and Micronutrients until the turf grows the fungus out.

olive123
11-20-2009, 06:32 PM
eagle is a very good product however it is one of those to be well known for fungi to develop resistance to. I like to switch em up.

RMA
11-20-2009, 06:49 PM
I haven't ran it that yet but I consider myself still very new to the industry! I will keep that in mind while applying eagle thanks for your input.
Rob
Posted via Mobile Device

greendoctor
11-21-2009, 01:56 AM
eagle is a very good product however it is one of those to be well known for fungi to develop resistance to. I like to switch em up.

That is why lawns with known fungal issues are on a rotation. The other reason is that the FQPA limits the number of applications to an individual site per year. In another time, there was no such thing as no more than 2 applications of a product per year. Idiots. What if the growing season is 365 days?

RigglePLC
11-21-2009, 09:50 AM
Eagle (myclobutinol) is in the fungicide resistance Group 3. According to Frag. (Fungicide Resistance Action Group). Do not rotate to another Group 3 fungicide. After two applications you should switch, perhaps to a to a strobin type, Qol group, or an old standby like Chipco as a rotation.

Landscape Poet
11-24-2009, 11:53 PM
New to this site and very happy ive found it!!!!!!! I also spray lawns on the west coast of Florida.. Ive had my dealings of gray leaf spot, seems to be everywere some lawns worse then other.. To put my 2 cents in, #1 cause of fungus is duel mower Blades, be sure whoever is mowing they are keeping shape blades on your turf. NEVER!! apply nitrogen while Gray leaf or any fungus is present all you will do is spread the fungus rapidly. Ive had great results with the chemical EAGLE, apply to dry turf and do not water in!!! 2 treatments 2 weeks apart.. Apply only your pesticides and Micronutrients until the turf grows the fungus out.

Mower Blades are the #1 cause - REALLY???? - I hope you are not telling your customers that your spray that! Although it is true that lawn equipment can spread it, so can kids running through the lawn, THE WIND etc etc. I hope you are not freaking people out about this and then they are questioning if their LCO is spreading this like we are some kind of prostitutes!

IMHO -Number 1 issue that causes fungus of any type- environmental conditions #2 - cultural practices (like watering at 5 in the evening and then letting it sit overnight until it drys/watering to much in our humid FL environment) #3 Micro's missing from the soil or a imbalance in them.

One other thought - while it is true that you can grow the fungus out - it is still not a guarantee that the fungus is gone - fungus spores generally have the ability to stay active in the soil for at least three years if I remember correct!

As others have said - changing the program up is the best practice - but yes Eagle is a good product

andyslawncare
11-25-2009, 12:53 AM
Why are they irrigating two times a week? Don't you get enough rain there in FL anyway? All you need is one inch per week. What is their irrigation timer set to? It needs to dry quickly! Also, Nitrogen in St. Augustine with fungus is a horrible idea! Don't DO IT! You should top dress and definitely aerate if it hasn't been done this year.

greendoctor
11-25-2009, 01:03 AM
Eagle (myclobutinol) is in the fungicide resistance Group 3. According to Frag. (Fungicide Resistance Action Group). Do not rotate to another Group 3 fungicide. After two applications you should switch, perhaps to a to a strobin type, Qol group, or an old standby like Chipco as a rotation.

Speaking of FQPA, no Chipco or Vinclozolin on residential turf. It is a scary thought that the only fungicides available are DMI, strobins, thiophanate methyl(probably next) and Prostar.

Landscape Poet
11-25-2009, 01:16 AM
Why are they irrigating two times a week? Don't you get enough rain there in FL anyway? All you need is one inch per week. What is their irrigation timer set to? It needs to dry quickly! Also, Nitrogen in St. Augustine with fungus is a horrible idea! Don't DO IT! You should top dress and definitely aerate if it hasn't been done this year.

No, contrary to popular belief, we do not always get enough rain here! 50 inches or so here in Central FL annually, but periods are very dry!
It is common to irrigate twice a week in FL during summer because of the heat. Some will set to give 1/2 inch each cycle. During winter it is once a week and adjusted to 1 inch.

And you are correct that putting N on fungus is not a good idea, it is kind of like putting lighter fluid on the grill, if you do it just sit back and watch it get out of control

greendoctor
11-25-2009, 01:21 AM
Because of the limitations imposed by the FQPA, cultural practices are key to controlling most, if not all turf diseases on residential turf. I do not like dull lawn mowers either. It is hard to quantify, but that represents an additional stress, something the grass must expend energy dealing with, which should be directed at resisting disease. Other stresses are nutritional issues and soil chemistry problems. Lastly, I also agree with an inch of water from rainfall, with additional water from irrigation to total an inch per week. On this last one, terms of service my customers agree to is that I have control over the irrigation system. As long as they have the right to call me and ask what is happening to their lawn, I have the right to set the irrigation schedule and correct any coverage issues in their lawn. In the parts of the island that are away from the coast and less sandy, most lawns are watered only once a week. Due to the low ET from the higher humidity, I am often putting down less than an inch of water. A full inch would stay soaked for almost a month. Most homeowners either overwater or underwater their lawns if left to their own devices. In the dry parts of the island, you need to put down an inch per week in increments. No cheating, that will show up as dead grass. Finally, absolutely no watering at night or after 3 PM. Grass that has water on it after 3 PM stays wet all night.