I have never been able to find the Bayer stuff here either but I use BannerMaxx which is extremely effective and works the same way as Bayer. You have to buy BannerMaxx on line and there is a cheaper product with the identical main ingredient. Ortho Rose Pride formerly Funginex is not as good as Bayer or Banner and costs 2 1/2 times as much per gal. of spray and has to be used more often. I would buy Banner or its' equivalent on line or the Bayer product based on all the favorable recommendations it has received here. Don't waste your time with Ortho.

I agree with Henry. The Ortho triforine product is satisfactory if you start early and use it every week, but will not give complete control under high disease pressure. The effectiveness may be similar to organic remedies such as sulfur and Cornell mixture.

Addiesue, see if your Lowes will order it for you. Or, you should be able to purchase it from Lowes online and select the "In-store pickup" option (free shipping to the store).

If not, then there are a couple of fungicides that have the same active ingredient as Banner Maxx (a systemic): Bonide Infuse and Fertilome Systemic Fungicide. Either of those in combination with mancozeb (Bonide Mancozeb Flowable), which is a surface fungicide, will work just fine. Call the local stores to see if they carry these products.

I'll recommend going ahead and ordering the Bayer online. It costs a lot up front, but my bottle has lasted three years now so you won't run out for a long time. You can also see if one of the local nurseries will order some.

Here is a link to purchase it at Lowe's

Here is a link that might be useful: BAYER ADVANCED Disease Control

Thanks decobug...I ordered 3 bottles this evening. Hopefully my roses will snap back. I appreciate everyone's input.

Addiesue

I guess I'm confused. Bayer's product claims to KILL existing blackspot spores? Not only prevent them, but kill them if they show up? Has this claim been verified? Do the spots disappear from the leaves?......Also the active ingredient in Bayer is 2.9% Tebuconzole. Is this a different name for Propiconazole which is the active ingredient in Banner Maxx or is it a different chemical? Banner Maxx has 14.3% of its active ingredient while Bayer has only 2.9%. Does that translate into using more of the Bayer product? In the end that would mean that the Bayer product wasn't as cost effective as Banner Maxx (or its cheaper generic form Honor Guard) as a preventative....I get the big whoop about Bayer if in fact it does KILL active infections, but after years of spraying as a preventative I really have a hard time believing that claim. I hope someone has some answers to my questions.

Maryl,

Generally, fungicides don't kill dormant spores, except for certain disinfectant products that aren't useful in the garden.

Surface-protectant fungicides such as mancozeb, Compass, and Daconil kill the spore as it germinates and attempts to penetrate the leaf surface.

Modern systemic fungicides such as Banner and Bayer are both surface-protective and potentially curative, depending on the fungus and the host plant. I have read research about Bayer and blackspot which found that tebuconazole is only 85% effective as a surface protectant (preventative). However, it is highly effective as a curative, able to destroy the fungal body already established within the leaf.

Spots don't disappear, but the fungus stops functioning and the leaf survives, providing it has not been too badly damaged already. Infections 10 days old were arrested by tebuconazole applied at that time.

Propiconazole (Banner) may well do the same thing, but hasn't been studied as much.

What Rosemania has been saying about their recommended fungicides is backwards wrong. Mancozeb is a surface-protectant or preventative fungicide that only kills spores when they are actively germinating on the leaf. Banner is a systemic with probable curative activity, as well as some preventative action.

Banner and Bayer are different chemicals from the same family. The package of Bayer sold at garden centers has been diluted in order to get the "Caution" label rather than something stronger. Therefore you have to use more of it per gallon of water. However, Bayer costs only 31 cents per gallon of spray mix.

To find the research I referred to, search: tebuconazole diplocarpon bonn. It is a PhD dissertation. There is also a journal article based on it.

Gee thanks Michael. I usually don't have outbreaks of B.S. because I spray when appropriate, but occasionally life happens and it blows up in my face. When that happened a few years ago I was told that for active infections to combine Mancozeb with BM when I sprayed. I'm thinking that's still good advice? Also since Mancozeb is not in the same class of fungicides as BM, you double whammy the protective power without building up resistance. I need to run a sick cat to the vets so I need to go. I appreciate any more input you care to give.......Maryl

Mancozeb and Compass are very effective preventatives (as is Daconil, if weather permits). It is good practice to combine or rotate them with Banner/Bayer to guard against resistance developing. However, from what I understand, Rosemania's "3 x 3" mancozeb treatment makes no sense, and you would be better off just to spray the combo. I'm sure that would be the case with Bayer.

I'm sorry to say I'm in ignorance of what Rosmania has to say about a spray schedule (3x3), and apparently that's a good thing. Since I normally have no problems with BS because of my preventative spray schedule I haven't paid much attention to the new kid on the block-Bayer. BTW I spray with Fungunex (Orthos Rose Pride) until the hot weather arrives as it is very effective against PM (as well as BS). Not so Banner Maxx, but don't know about the Bayer product. Thanks Michael for all your information. The killing power of Bayer was news to me and I appreciate it.

Mary, nothing will get rid of the existing spots on leaves. You will have to remove those leaves if they bother you. But it will stop the fungus that is already on other leaves but isn't showing yet.

Addiesue,
We bought ours from Star Nursery....if you google it, I think it's either in New Mexico or Arizona....can't remember. We used it very successfully for a few years. It does say that it actually KILLS EXISTING B/S. I believe it....it was great, but we found out that in NYS it's illegal to use (tebuconazole). Wish it were legal here, as it worked very well for us.
Phyl

There is research that shows how tebuconazole (Bayer) and propiconazole (Banner) act as a preventative. There is NO research that indicates that either kills fungal cells. The exact way they work is well known and has been explained here. Members of this family of fungicides seem to maintain their effectiveness longer and better than other alternatives tested and it has been suggested that this is due to their greater systemic capability.

Thanks everyone for your input. Atleast I feel like there is hope now.

Addiesue

I stand corrected, Henry....sorry! I hadn't taken the time to read all that had been posted, instead skimmed over the posts and just gave my less-informed 2 cents.
Hope your roses are great this year, Addiesue!
:0) Phyl

The fungus is not just"cells," rather it is an organism with a structure. I have posted links to microphotographs showing how tebuconazole breaks up the fungal body within the leaf so it is not able to do further damage. Of course, no fungicide could repair damage that has already been done to the systems within the leaf. And of course it does not erase the spots on the leaf surface.

Here is the abstract of the paper sent to me by Henry Kuska. It is available on line only if you buy it from the publisher. I cannot repost the complete paper he sent me other than to print and mail copies. I have read it carefully and it explains how two types of fungicides work and why triazoles apparently have a much longer lasting effect. My understanding is that triazoles do not break up the formed fungal body but rather prevent it from forming by inhibiting a vital component of the cell membrane. Thus the cell membranes are collapsed prior to formation but the action of fully formed fungal cells is irreversible. Damage already done runs to its' conclusion but further damage is prevented.

Here is a link that might be useful: Efficacy of triazoles....in controling blackspot of roses

"Triazoles ...allowed germination of some of the D. rosae conida...but germinated conida did not establish infection or lead to symptom development. This can be explained by the fact that during the initial phase of infection, fungi sensitive to sterol inhibitors contain enough ergosterol in the germinating spores to produce germ tubes and infection structures and to penetrate into the host tissue. When the fungus has depleted its' ergosterol and has absorbed...the fungicide from the plant tissue, the effect of the chemical becomes obvious...the uptake of the chemical inhibits the production of ergosterol (vital in stabilizing the cell membranes in the fungi) by the fungus and the fungus is killed by the depletion of the sterol building blocks necessary for the cell membrane. Application of triazoles early in the development of D. rosae led to almost complete inhibition of symptom development. Their application at the onset of symptom development arrested further symptom development giving significant reduction in symptom severity. This indicated that triazoles degraded fungal structures in the host tissues in such a way that further growth was inhibited."

whatever. It works.

Yes. The first 3 sentences refer to the protective or preventative function when the fungicide was applied before infection with the fungus. The spore germinates and penetrates the leaf where it "is killed" by action of the fungicide. Apparently this is a stage later than when the surface-protectant fungicides like mancozeb and Daconil do their work-- when the germ tube encounters the fungicide on the surface of the leaf.

The last 3 sentences refer to the "curative" function when the fungicide was applied 3-10 days after infection by the fungus. Tebuconazole "degraded fungal structures" and stopped their growth. If applied 3 days after infection, it prevented the development of spots; if applied 10 days after infection when spots were already visible, it stopped the development of the fungal body and allowed the leaf to survive.

The article is based on the pHD dissertation by Gachomo which I think is on the open web.

Here is a link that might be useful: blackspot research

Just out of curiosity I got out my book 'Diseases & Pests of Ornamental Plants 5th edition' by Pascal P. Pirone. Under the subject of B.S. and roses this is what is stated ..."While the powdery mildew fungus threads are almost entirely superficial, the threads (mycelium) of the black spot fungus are mostly under the protecting cuticle, so that fungicides cannot kill the fungus without destroying the leaf." Apparently we've moved on in modern chemistry since Mr. Pirone's 5th edition. No wonder I get confused.....

This may be semantics. What is clear is that triazoles stop D. rosae dead in its' tracks with tebuconazole being the better of the two tested. There is no further expression of symptoms. Spots on foliage are not cleared up but there are no new ones and damage doesn't get worse. This is pretty good. Is this curative or preventative? I guess it doesn't matter. The authors also believe that triazoles are very systemic which is extremely important for effectiveness. The other class of fungicides in the study had strong initial effectiveness but it didn't last. It also seems apparent that trying to prevent D. rosae by spraying to kill the D. rosae conida before they can germinate is far less worthwhile than using a systemic which prevents damage even after germination has occurred and in addition you don't have to worry about covering all surfaces. The implication? If you have a severe outbreak don't bother with Mancozeb...spray tebuconazole as the most effective way to stop the outbreak of symptoms and prevent further damage. I have one last question which is are the various triazoles more or less equal in effectiveness? The study suggests they aren't since tebuconazole had more lasting effectiveness than the other triazole tested. It is a ringing endorsement for tebuconazole (Bayer) but not necessarily for others such as propiconazole (BannerMaxx). Based on this I may actually switch to Bayer.

Henry, the other systemic fungicide in the study was the chemical sold as Immunox. It's too bad we don't yet (so far as I know) have a comparative study of propiconazole and tebuconazole vs. blackspot, but we do have gardeners' experiences that both are highly effective. One difference is that Bayer may be used at 7-day intervals if needed. This may mean that it is less prone to growth-regulating effects, but a comparative study on roses is wanting.

Thanks all. I didn't have much luck with tebuconazole the first time I tried it, but I will try a controlled study in my own yard, compared with mancozeb/propiconazole.

This may be semantics. What is clear is that triazoles stop D. rosae dead in its' tracks with tebuconazole being the better of the two tested. There is no further expression of symptoms. Spots on foliage are not cleared up but there are no new ones and damage doesn't get worse. This is pretty good. Is this curative or preventative? I guess it doesn't matter. The authors also believe that triazoles are very systemic which is extremely important for effectiveness. The other class of fungicides in the study had strong initial effectiveness but it didn't last. It also seems apparent that trying to prevent D. rosae by spraying to kill the D. rosae conida before they can germinate is far less worthwhile than using a systemic which prevents damage even after germination has occurred and in addition you don't have to worry about covering all surfaces. The implication? If you have a severe outbreak don't bother with Mancozeb...spray tebuconazole as the most effective way to stop the outbreak of symptoms and prevent further damage. I have one last question which is are the various triazoles more or less equal in effectiveness? The study suggests they aren't since tebuconazole had more lasting effectiveness than the other triazole tested. It is a ringing endorsement for tebuconazole (Bayer) but not necessarily for others such as propiconazole (BannerMaxx). Based on this I may actually switch to Bayer.

Spectricide manufactures Immunox. It's main active ingredient is Myclobutanil....Yes, I do believe that with all the above information If I ever have a bad BS infection I might try the Bayer product over using the standard Mancozeb/Fungunex or Mancozeb/Banner Maxx forumula...Maybe there will come a day when we don't have to spray preventatively at all, only if we see an active infection. As human beings we certainly don't take antibiotics all the time just in case a germ happens to come along.

okay, but aren't we killing our bees with all this stuff??

No. Fungicide is not an insecticide.

There were no bees harmed in the making of this thread.