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View Full Version : Fungus Control....let it go and reseed?


Teach123
07-16-2012, 07:47 PM
After much research, an agronomist, entomologist, I finally think I have figured out what has been the culprit in my turf for 3 straight years. To make a long story short, there is a fungal problem (leaf spot melting out) Occurs in the same spots year after year. Question: I know Heritage and Compass have shown good control, but do I treat now as a curative? Or just rake out in Fall and reseed with good disease resistant cultivars via NTEP. Then use Heritage or the like in Spring (2 week intervals) as a preventative.

I do know fungicides are $$$$$, but I also know I should alternate back and forth between a couple so that the fungus doesn't build up immunity. Would using a high-priced like Heritage/Compass and a low priced like Spectracide work??

In addition, I am going to resist the temptation to dump N on the turf in spring and put the bulk of my fert down this fall. I think this cultural practice, coupled with a preventative fungicide should work.

Ideas??

RigglePLC
07-16-2012, 08:18 PM
Melting out is seldom a problem during hot weather. Get a second opinion. Be sure it matches the pictures like these:
http://www.google.com/url?sa=t&rct=j&q=melting%20out%20turf%20grass&source=web&cd=3&ved=0CFYQFjAC&url=http%3A%2F%2Fwww.plantpath.iastate.edu%2Ffiles%2FSUL13.pdf&ei=fa0EUMjBAcmorQG7u4zUCA&usg=AFQjCNFd79ZVfdpBO700llzYEkPVmE0BAA&cad=rja

The best control is to overseed with newer more disease-resistant bluegrass varieties. Avoid Parade and Newport--and all cheap seed. Include top quality perennial ryegrass if you wish--it comes up quicker and is not susceptible to melting out.

Be sure you are not looking at red thread or brown patch disease.

Teach123
07-16-2012, 08:34 PM
Riggle: The site you posted was the exact one where I found the address for Iowa State's disease identification center. I sent them a sample, and even though I am not a Iowa resident, they emailed me their findings and will send a follow up written evaluation.

As far as seed...not gonna do PRG again. I'm going with 100% KBG. I will visit NTEPs site to see which ones show good disease resistance. I think the rye is what has the disease right now. The elite KBG seems to be doing great.

DA Quality Lawn & YS
07-17-2012, 12:26 AM
Make sure it is not Necrotic Ring Spot. If it is, you will not want to reseed with KBG, or at least non-disease resistant KBG. And plan on a multiple year process to simply reduce the effects of the fungus. Far as I can tell, it can't be eliminated totally, I have tried almost everything.

Smallaxe
07-17-2012, 08:01 AM
... In addition, I am going to resist the temptation to dump N on the turf in spring and put the bulk of my fert down this fall. I think this cultural practice, coupled with a preventative fungicide should work.

Ideas??

A lot of cool-season grass experts(midwest extension offices) agree that this cultural practice is best, for a number of reasons... in the case of fungus, it makes sense, becuz rapid watery growth is more subject to all kinds of disease problems...
Personally, I'll startup fertilizer once things cool off in Aug,if the rains start then again in early Oct for a winterizer...

Teach123
07-17-2012, 09:30 AM
A lot of cool-season grass experts(midwest extension offices) agree that this cultural practice is best, for a number of reasons... in the case of fungus, it makes sense, becuz rapid watery growth is more subject to all kinds of disease problems...
Personally, I'll startup fertilizer once things cool off in Aug,if the rains start then again in early Oct for a winterizer...

Smallaxe, In the near future, I do want to hear about your Milo routine. I assume you are still using it. I think I am going to go mostly organic next year. I have soil sample pending (should get the results today or soon). I have recently made a homemade soil conditioner which is very similar to Aerify Plus and Kelp Help and I hope to make any soil amendments organically. Although, some calcitic lime may be the quickest way to sweeten the soil.

As far as Milo, I know people have used it as various rates with success. I was thinking maybe bag rate on the first of each month. Again, hate to have disease issues, but the turf has to eat right?

Pythium
07-17-2012, 11:47 AM
If you do choose the fungicide route..be sure to switch chemical families labeled for the disease to prevent resistance. Resitance issues usually arise after several (like all you use) repeat applications. Heritage and compass are both strobilurins same family very similar modes of action. OSU has a great chart on chemical families http://turfdisease.osu.edu/publications/turfgrass-fungicide-table-updated downloadable pdf

Teach123
07-17-2012, 11:56 AM
If you do choose the fungicide route..be sure to switch chemical families labeled for the disease to prevent resistance. Resitance issues usually arise after several (like all you use) repeat applications. Heritage and compass are both strobilurins same family very similar modes of action. OSU has a great chart on chemical families http://turfdisease.osu.edu/publications/turfgrass-fungicide-table-updated downloadable pdf

Thanks for the link. I was told to stay away from the DMIs for some reason..I don't remember where I read that. Maybe from a study i read from Purdue regarding leaf spot. I believe the same study said Heritage had best results. So I guess I'll go with that and choose one from another family. Again, thanks for the link.

Pythium
07-17-2012, 12:06 PM
DMIs can have growth regulating effects and other undesirable side effects if used incorrectly. Not sure if melting out is on their labels or not. High rate of resistance too, but so does heritage.
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Teach123
07-17-2012, 12:23 PM
DMIs can have growth regulating effects and other undesirable side effects if used incorrectly. Not sure if melting out is on their labels or not. High rate of resistance too, but so does heritage.
Posted via Mobile Device

Let me ask you this...Would applying at a curative right now be effective to save what healthy turf I have? Or is damage done so to speak. I mean, using good cultural practices now (i.e no N, watering to keep good turf, etc...) to wait it out until topdressing and reseeding this fall. My thought is that the disease attacked the non-elite KBG cultivars from previous sod and PRG that was there. The elite disease resistant cultivars of KBG are probably what is left. I seeded that last fall, but I think the PRG that was in the mix took over.

Thoughts??

Pythium
07-17-2012, 01:04 PM
I wouldn't do a fungicide now. Why not the disease wipe out the less resistant turfs? Then since you are seeding anyway, seed your elite kbgs into the areas killed by the disease. Watch the area next year and at when conditions favor disease development apply your fungicide. Resistance doesn't mean immune. I like heritage because of the 21-28 day residual.
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RigglePLC
07-17-2012, 01:43 PM
Melting out does not attack perennial ryegrass. Take careful look at the information on red thread disease, (a common problem on ryegrass). Particulary if nights are warm and humid. I think Heritage fungicide works nicely on red thread.

http://www.extension.purdue.edu/extmedia/BP/BP-104-W.pdf

For red thread keep the fertility level fairly high, avoid watering after 5 pm, and try to change watering to three times per week only more deeply. The goal is to reduce the leaf-wetness time per week and to reduce the overall average humidity.

Teach123
07-17-2012, 02:15 PM
Melting out does not attack perennial ryegrass. Take careful look at the information on red thread disease, (a common problem on ryegrass). Particulary if nights are warm and humid. I think Heritage fungicide works nicely on red thread.

http://www.extension.purdue.edu/extmedia/BP/BP-104-W.pdf

For red thread keep the fertility level fairly high, avoid watering after 5 pm, and try to change watering to three times per week only more deeply. The goal is to reduce the leaf-wetness time per week and to reduce the overall average humidity.

Thanks Riggle! Whatever it is, the elite KBG did not suffer the same fungal issue. Like Pythium said above, I think whatever species got the disease will be raked out this Fall and the spots will be topdressed and seeded with the same resistant KBG as is in there now. Award, Freedom, Midnight, and Bedazzled. This coupled with the cultural practices you suggest should alleviate the issue a little year by year.

Smallaxe
07-17-2012, 02:30 PM
Smallaxe, In the near future, I do want to hear about your Milo routine. I assume you are still using it. I think I am going to go mostly organic next year. I have soil sample pending (should get the results today or soon). I have recently made a homemade soil conditioner which is very similar to Aerify Plus and Kelp Help and I hope to make any soil amendments organically. Although, some calcitic lime may be the quickest way to sweeten the soil.

As far as Milo, I know people have used it as various rates with success. I was thinking maybe bag rate on the first of each month. Again, hate to have disease issues, but the turf has to eat right?

I schedule the Milorganite just prior to and just after, the heat of summer... It is more expensive than synferts, but it only releases when water is available so it is not going to add stress to the overheated grasses, during this critical time(at least that is the claim)
This year I had the milo on the turf in May becuz the color was fading and the iron really made a good color before everything began heat dormancy... :)

grassman177
07-17-2012, 05:22 PM
I wouldn't do a fungicide now. Why not the disease wipe out the less resistant turfs? Then since you are seeding anyway, seed your elite kbgs into the areas killed by the disease. Watch the area next year and at when conditions favor disease development apply your fungicide. Resistance doesn't mean immune. I like heritage because of the 21-28 day residual.
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depends on if they are willing to let it all die or not, i spray if i think i can save it, cuz why not? i have planted many dif varieties over the years, in melting out and necrotic ring spot areas, with none of them ever truely out performing the others, so fungicide is a must.

so, depends on many things. i have let grass die though as in your suggestion and had great results switching varities and avoiding the issues in subsequent years. you never know till you try i guess

Teach123
07-18-2012, 11:02 AM
depends on if they are willing to let it all die or not, i spray if i think i can save it, cuz why not? i have planted many dif varieties over the years, in melting out and necrotic ring spot areas, with none of them ever truely out performing the others, so fungicide is a must.

so, depends on many things. i have let grass die though as in your suggestion and had great results switching varities and avoiding the issues in subsequent years. you never know till you try i guess

Its the chance I take...sighhh. Let me ask you this. If I did go ahead and pick up some Heritage or Compass, would doing a few apps now only raise the likelihood of some resistance next Spring Early Summer? I am going to try the NO N policy next spring, but also want to do the fungicides as a prevent throughout the growing season next spring. As Pythuim suggests, gotta do fungicides from two different families and could get expensive if I have to keep getting new products. Thoughts??

grassman177
07-18-2012, 02:47 PM
i dont think you will get resistance that fast, no.

no N in spring is a good one, i like it but it is not a fail safe by any means.

Smallaxe
07-19-2012, 04:59 AM
For a preventative I've heard a lot about cornmeal being used... it is also used as a fertilizer...

Teach123
07-19-2012, 08:01 AM
For a preventative I've heard a lot about cornmeal being used... it is also used as a fertilizer...

That's what I have been reading. I bought a couple books about organic lawn programs. The problem, and the book explains this, is that organic stuff can be hit or miss for the first few years. Kinda gotta let things play out and see what was effective. That's hard to do when it seems you one one shot in the spring produce a summer long good stand of turf.

Smallaxe
07-19-2012, 09:25 AM
That's what I have been reading. I bought a couple books about organic lawn programs. The problem, and the book explains this, is that organic stuff can be hit or miss for the first few years. Kinda gotta let things play out and see what was effective. That's hard to do when it seems you one one shot in the spring produce a summer long good stand of turf.

It certainly won't hurt to try, and since it is a fertilizer it shouldn't be added too early in the season... it does have to decay for the nutrients to recycle and it may very well be, that it is the microbrial activity of the decaying process, that outcompetes the pathogens...

Also I would look at the current cultural practices that may cause the problem to begin with...

Teach123
07-19-2012, 09:51 AM
It certainly won't hurt to try, and since it is a fertilizer it shouldn't be added too early in the season... it does have to decay for the nutrients to recycle and it may very well be, that it is the microbrial activity of the decaying process, that outcompetes the pathogens...

Also I would look at the current cultural practices that may cause the problem to begin with...

Oh, I have no doubt in my mind that my cultural practices, especially those regarding N, have led to this problem. Turf maintenance consists of dealing with lots of variables. The "no N in Spring rule" is a variable I haven't controlled. Hence, this stupid leafspot each year. You have Scotts/Ortho out there selling people (myself included the past few years) Halts w/Fert. in March. At the bag rate you are applying almost a lb. of N with the Pre-m. A pound!

There has been much debate on this site regarding how people feel about Scotts. IMHO...I think they know a great deal about lawn care, but also know that people want green grass quickly. They are also making tons of money off people that must buy their disease control, weed control, and seed after lawns go to crap because of high synthetic N. Maybe others have had no issues..who knows.

I just want my soil test results so I can start amending organically. I can already hear my lawn thanking me. It knows relief is on its way :)

grassman177
07-19-2012, 01:53 PM
excellent attitude and idea for amendments and soil tests.

good luck

Teach123
07-19-2012, 02:18 PM
excellent attitude and idea for amendments and soil tests.

good luck

Thanks Grassman! I am a teacher with summers off and have taken up lawn care as a hobby. It interests me to no end. And it keeps me busy and out in the sun without being lazy. :)

grassman177
07-19-2012, 02:24 PM
awesome. you sound like you are def researching, and gaining knowledge, might turn pro one day, lol

Teach123
07-19-2012, 02:33 PM
awesome. you sound like you are def researching, and gaining knowledge, might turn pro one day, lol

Yep, doing lots of research. At the moment, contradicting myself as I look at studies based on chemical control of Poa Triv. Maybe I'll start the organic thing after the chemical-filled reno I am going to have to do this fall. Going pro...no one would hire me if they saw my current stand of turf. It aint pretty :)

ChiTownAmateur
07-19-2012, 04:45 PM
I think your quest to go organic or be more organic should be put on hold pending a successful and relatively disease free lawn. If you can get the lawn in good shape with a minimum of chemicals, that is a better step forward than trying to go organic and starting over several more times.

I think you may also overanalyze this a bit. Keep in mind that this spring and summer have been off the charts in temperature and lack of rainfall. Even if you water, normal watering practices have not been sufficient this year.

The grasses begin the transition to dormancy pretty quickly in our areas because they aren't designed for 90-100 degrees and sunny every day, let alone without rain. During the transition in and out of dormancy, it becomes more succeptible to disease because it is weaker during those times.

I would use a systemic broad fungicide and irrigate it quite a bit soon afterwards (right away with granules, as soon as allowed on the label if using a spray). As one of the folks says above, why not save what you can? Regardless of what is saved or not, you overseed with an ideal mixture of KBGs or a combo of those with some rye and hearty fine fescues. Any seed used should be very high quality.

Don't overmanage nature, let it take it's course and adapt to it more than trying to go the other way and artificially manage your lawn. There's no shame in putting down an app or two of fungicide next spring as a preventative. The goal is to establish a hearty lush lawn that doesn't need any help in the long term. If the short term requires some nurturing then do it.

In the long run, once you get to that point then I would consider the switch to organic. Otherwise, you'll never figure out what is and isn't working because there are too many variables.

RigglePLC
07-21-2012, 02:18 PM
If the problem is red thread, rust or dollarspot--low fertility makes it worse. Brown patch is stimulated by high fertility levels, at least in hot weather. Gray leaf spot on the ryegrass parts of the mixture is a possibility. Nitrogen should be maintained at adequate levels, but applied in cool (not hot) weather.
http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&sqi=2&ved=0CF8QFjAA&url=http%3A%2F%2Fohioline.osu.edu%2Fhyg-fact%2F3000%2Fpdf%2F3083.pdf&ei=7vEKUOrbCcKnrQGtxJCxCg&usg=AFQjCNHJ6ooVrRPBlh8n1t3eV_Zy6RfFpg

Smallaxe
07-22-2012, 09:22 AM
Riggle makes a good point... too much N you get disease... too little N, and you get more diease... fertile soil is better than spiking N every few weeks...

That's the major difference between a natural(organic) grassland and typical synfert grasslands or lawns... however, I don't know of much in organic ferts that supply adequate N in the autumn, w/out a lot of money...

I believe the strategy for going from synthetic to organic is to building a fertile soil and adding less and less N for the same results or often times, better results... organic lawn care has fallen into disrepute becuz there is the mandate of accepting a lower quality turf for more money...

The way to look at it is: A fertile soil can uphold healthy plants with less input... JMO... :)