Addiesue

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.

Addiesue

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.

Addiesue

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.

Firstly I live on a mountain above Honolulu at a height of 1000 ft, our average temperature year round ranges from 78 F - 82F daytime to 72 F at nighttime in the summer, and 72 F - 75 F in the winter daytime, and 70 F to 64 F nighttime in the winter. In our particular location it rains more in the evening and night than in the day; perfect for blackspot. Even some of the so-called very BS resistant varieties get blackspot, although I have a few that get none at all.

I have not grown roses for over 30 years as many persons who live here stated they are too hard to grow in Hawaii; 30 years ago I grew then in the UK. But with a little extra attention in the last 9 months I have had good success with growing roses, being carefully to monitor the moisture of the soil so I do not over or underwater as our rainfall is inconsistent in its amount; and fertilizing primarily with organic fertilizers.

The reason for my comment is to add my experience with blackspot as it relates to Hawaii. Initially, 9 months ago, having no experience with BS, in Hawaii, I prepared and planted both garden and container roses. For a while, 2 months, they did well, and then we received some heavy rains and also some days of torrential rain from a hurricane, which came close to the islands. Then the blackspot monster went into full swing. It looked as if most bushes had been playing strip poker leaf and they all lost!

After having read that it is best to change systemic fungicides (Tebuconazole and Triforine) every second week, so that resistance strains of BS do not develop, I began as follows:

Starting with the Tebuconazole (Bayer Disease Control), with good but not great results, alternating every 3rd week with chlorothalonil (Ortho's Garden Disease Control).

Then I alternated by spraying triforine (Ortho's Rose Pride) for every seventh day for two weeks, then on the third week's seventh day chlorothalonil (Ortho's Garden Disease Control), followed then every seventh day for two weeks with tebuconazole (Bayer Disease Control); this produced much better results but still a little BS.

The following schedule produced the best results, with a near complete elimination of BS, and nice full bushes within 6 weeks to 2 months, by spraying every seventh day:

Week One and Two: Tebuconazole (Bayer Disease Control) - systemic
Week Three and Four: Triforine (Ortho's Rose Pride) - systemic
Every Week: Chlorothalonil (Ortho's Garden Disease Control - protectorant
Then back to the beginning.

One important point is I do add a sticker to all, and I do spray both the top and the bottom of leaves for full coverage. I do believe this makes a difference.

As Chlorothalonil is a protectorant and not a systemic like the others it is highly unlikely that resistance will be built up against it, so spraying weekly is not an issue.

So I believe that that whether Bayer or Ortho is better is sort of mute as it is best if one wishes to avoid BS resistant strains to alternate as the experts suggest, especially here in Hawaii's BS heaven, where there it is always open season for BS.

I am not an expert but can only give you my personal experience.

As regards bees it has been suggested that the Bayer product could have issues but this has not been proven, they suggest it is best to spray early in the morning before they arrive. My own garden is now Bee Central, sometimes in the front garden it sounds a if we have hives out there, great for keeping dog walkers away from our garden, so I think Bayer is OK with bees so long as one sprays either early or after they have left for the day, as suggested by Bayer.

It has also been suggested by some studies that Triforine does not a develop a disease resistant BS, however I like to sit on the side of safety by spraying Bayer very early in the morning, and changing to Triforine on the third and fourth week.

My own personal observation is that Triforine might be slightly better than Tebuconazole, but that might be just something to do with our climate. But spraying weekly in combination with the protectorant chlorothalonil (Ortho's Garden Disease Control) makes the most difference.

I also read by doing this every 10th or 14th day greatly reduces the performance, most agricultural studies say every 5 - 7 days for the best results.

Hope this helps

And yes I know I should have done more research and bought and planted more "Old Rose Varieties" or at least joined and checked with the "Honolulu Rose Society" as to which roses are BS free. I have two varietes that are, one being the local "Lokelani Rose" gets a tiny bit but shrugs it off on its own. The other unknown that gets none at all and is I believe a hybrid tea.

Remember back a few years ago when you couldn't even get a loaf of bread on Sunday shortly befor that one couldn't even cook a loaf of bread on that very same day
my my how fast we have moved along this road
how is it we are so willing to exert more time and efforts on fix all products in our lives in the fast lane than we are in just reflecting.

Look mom theres a new bottle of fix all form a newly dressed snake oil sales man that goes by a differnt name

Ortho is great, if you want to spray every week. It's not a systematic, so it can only last that long. The Bayer formula is systematic and you can go 2-3 weeks between sprays. I used to use Daconil, and while it did a great job, I had to spray weekly and a couple of my roses didn't like it (Double Delight was the main culprit).

With the Bayer, I effectively cut my spraying in at least half (every other week, longer in dry weather) and I don't have any negative reaction.

The issue with Bayer/Bees was with the drench which also included an insecticide, not the fungicide.

My apologies, you are correct and I wrote incorrectly when I stated the Bayer Disease Control may have issues with bees, it does not, as you wrote it is the Bayer Complete Insect Control that does, so no more getting up before dawn for me on Sundays, thank you.

I agree Ortho RosePride Disease Control (Triforine) works very well, however it is a systemic, but not a full systemic like Bayer's, it is classified as a local systemic, I believe but am not sure, that the Ortho Product stops BS new infection, and can clear infection that is not older than 5 to 10 days. Whereas it seems the Bayer product does this as well as destroying older existing infections.

Here are three web addresses that might be of interest:

"http://plant-disease.ippc.orst.edu/articles.cfm?article_id=14"

"http://edis.ifas.ufl.edu/pdffiles/PP/PP26800.pdf"

"http://www.frac.info/frac/index.htm"

The last one above might interest you it is the Fungicide Resistance Action Committee's website, the PDFs are a little out of my league but may be of interest to you or others that might have a strong science background.

Frankly I am not sure what the difference is between a local and a regular systemic, maybe you could help me there.

I did notice that the Bayer product and the Ortho product while having different active ingredients both are listed as class 3 fungicides, would this present a problem as regards the BS becoming strain resistant to both? Captan fungicide seems to be from group M4 and seems to be effective from what I read, any opinion on this?

Frankly I would like to use sulphur but the heat and intermittent rain preclude its use.

The nursery where I buy the roses uses copper based product but it seems very ineffective.

Thank you for your reply and I hope either you, or someone, might be able to clarify the above points/questions.

Sorry one more thought. I noticed you live in GA, we use to live in GA outside Atlanta, on the North West side, about 28 years ago. We loved it, great weather, mostly not too hot or too cold, for eight months of the year. With the world climate changing is it still the same? We had a beautiful garden with a stream running through the back, and so many green trees.

If we still lived there I agree with you that I might be able to get away with spraying once every two to three weeks. But here in Hawaii no way, as we have high humidity, high temperatures, and most importantly high UV, nearly most of the time. While one of these issues may not cause rampant BS the combination is something akin to a deadly cocktail.

If I fail to use Chlorothalonil (Ortho's Garden Disease Control) the protectorant, weekly, when it rains on some bushes, but not all, I can literally see the black spot develop before my eyes in a matter of hours.

So as I stated I think the program I use is only needed for Hawaii and other areas of the world with similar climates close to the same latitude. Your program obviously works well for you and I am sure if I ever moved back to GA, SC, or NC I would use your program.

2. I used the Ortho triforine fungicide exclusively for maybe 8 years. With faithful weekly spraying, I would get partial defoliation of typical hybrid teas-- maybe the lower 12" of canes within 5 months. Bad girls like Angel Face would lose more leaves than that. I switched to sulfur for the next 10 years because it was nearly as effective as triforine but safer. This year I've used Bayer exclusively with obviously better results than I got with Ortho. Many HTs haven't lost any leaves.

3. If you are looking for a rotation/tank mix partner for a class 3 systemic, there are the strobilurins such as Compass from Rosemania. This is a persistent surface-protectant fungicide with a novel mode of action. It is considered safer than chlorothalonil or mancozeb. According to the great German blackspot study, it is very effective in preventing successful germination.

Thank you for the explanation it was very clear.

I have not noticed any leaf loss with Triforine, however Compass does sound, from reading online after you suggested it, to be very effective and longer lasting.

Leaf drop was noted for Triforine in this study:

"http://www.ag.auburn.edu/aaes/communications/circulars/circular329.pdf"

The only issue is the initial outlay; Ortho's Rose Pride Triforine is about $20 including tax here in Hawaii, working out to be about $0.625 per produced gallon. Compass is around $240, working out to be around the same $0.622 per produced gallon. But it seems from reading Compass is a superior product.

If I go with Compass, the cost will work out to be less expensive, if used as a preventative - the same if used as a curative, as I will only need to use it once every 14 days versus once every 7 days, the real cost will actually be half of my calculated $0.62 per produced gallon, or $0.31.

My only concern is this, at the following link. What is your opinion on the maximum number of sprays yearly?

"http://www.apsnet.org/education/AdvancedPlantPath/Topics/Strobilurin/top.htm"

Would it be better to rotate among three, Bayer Disease Control, Ortho Rose Pride Triforine, and Compass to make sure there is no resistance build up?

It seems from reading Compass is much more effective than Heritage on roses, do you think my assumption correct? And do you have any opinion on Captan 50 WP, although Farmoz in Australia recommend no more than 5 applications per year?

"http://www.farmoz.com.au/Bulletin/FARMOZ/Captan_Bulletin.pdf"

On a lighter note we are now enduring "Kona Winds" in Honolulu which blows volcanic vog over the islands. This comes from the Big Island of Hawaii's volcanoe of Kilauea, this happens about 14+ days of each year. The Vog contains Sulphuric Acid a natural blackspot preventative. Of course if it lasts too long we cannot even see the roses.

Your insight as always is just great.

Thank you.

I think I found the study you mentioned here:

"http://deposit.ddb.de/cgi-bin/dokserv?idn=975616277&dok_var=d1&dok_ext=pdf&filename=975616277.pdf"

Please let me know if I am wrong.

It seems that Compass is best used as a preventative being not as good a curative if one looks at page 85 in this dissertation for Trifloxystrobin.

If I understand the dissertation correctly, it has great value in the rotation of systemics. Bayer's product and Triforine, it appears from other articles, are superior as a curative.

The only issue I see is that as it is a systemic it cannot be used weekly or bi-weekly as a preventative without a break, which Chlorothalonil can be as it is a non-systemic and is not known to have issues with resistance build up, so one might still want to use Chlorothalonil weekly if one wanted near 97% to 100% relieve from BS.

A more ideal weekly rotation might look something like this:

Week 1. Bayer Advanced Disease Control - Tebuconazole - systemic
Week 2. Compass - Trifloxystrobin - systemic
Week 3. Ortho's RosePride Disease Control - Triforin - systemic

Repeating the cycle at week 1.

In addition every week: Ortho's Garden Disease Control - Chlorothalonil - non-systemic preventative (Or am I doubling up?)

It could be that I do not understand this completely being a rank amateur when it comes to fungicide. What would you opinion be on these thoughts?

This old study might interest you, the writer really liked Triforine but could no longer use it; presumably they had used if too often and a resistant strain developed:

"http://www.chasehorticulturalresearch.com/pdfs/rose.pdf"

Thank you.

In order that the BS does not develop a resistant strain I added a week 4, using Captan a class M4 Fungicide, non-systemic.

It would then look like this:

Week 1. Bayer Advanced Disease Control - Tebuconazole - systemic - Class 3
Week 2. Compass - Trifloxystrobin - systemic - Group 11
Week 3. Ortho's RosePride Disease Control - Triforin - systemic - Class 3
Week 4. Captan 50 WP - hydroxyquinoline - non-systemic Class M4

Repeating the cycle at week 1.

In addition every week: Ortho's Garden Disease Control - Chlorothalonil - non-systemic preventative
- Group M5

The advantage of this is that it results in no more than 13 sprayings of each per year.

Any opinions,

Thank you.

To prevent resistance, you only need use two chemicals with different MOA, for example chlorothalonil and tebuconazole.

I have never used captan, which was already passé when I started in 1976. I wouldn't recommend it.

If I were using Compass, I would tank-mix it with tebuconazole and apply it every two weeks. It is not really a systemic but a persistent surface-protectant that binds to the leaf's surface layer so it doesn't wash off. It is probably safer for you and the plants than chlorothalonil but much more expensive.

Thank you for the above ideas.

I think I will try the tebuconazole each week for two weeks and then chlorothalonil for one week then back to tebuconazole as this seems to be the least expensive. Failing that I will go with the Compass method.

If there are any issues I will advise.

The trade winds are finally back with a light wind, enough to blow the vog away, thank goodness.

Blackspot is a huge issue here, at least in the early summer and fall (although that is probably anthracnose). I've found that the Bayer can last 2 weeks in the most intense BS periods. I also use it about once a month in the winter, as someone reported that it would help keep the blackspot away in early spring.

Unfortunately I've only been to Hawaii once, so I don't can't compare the conditions. I'd say you are probably equal to our most intense humid periods but for a longer time. But it gets a lot hotter here and we don't have the nice on shore breezes you have to cool us off.

Thank you for your post.

You are correct I may have anthracnose as well. As the temperature rarely goes above 82 F at our location, and never above 86 F even on the rare occasion when the trade winds stop, I am wondering whether this is good or bad; could it be that very high temperatures actually kill off these disease? If so you are luckier than me.

It seems from reading, but not experience, Compass does a good job on both these diseases. I am not sure whether it is our temperature, humidity, uv, or when the rain comes, being off and on either all day or all night for more than six hours, or a combination of all of the above that cause these diseases to be ever prevalent. I have tried spraying every 14 days but it causes these diseases to multiply. Every 7 days keeps them under control and comes close to eliminating them. For those of you that live in Hawaii this schedule may vary drier areas like Kaimuki, St. Louis Heights, Ewa Beach, etc., you might get away with 14 days cycles. In Manoa, the wet side of Waimea on the Big Island, and parts of Hilo I would think every 7 days.

Although I will buy Compass, I am beginning to be believe that my obvious best solution is to keep on trying different roses until I find ones that are resistant to these diseases, at present I only have one that is fully resistant, it never gets anything - sadly I do not know its name but it is either a tea or hybrid tea, and one local rose which gets them in a mild way but shrugs the diseases off. This I think will ultimately be less expensive than spraying and certainly less time consuming.

Interestingly I get very little to no bug issues in either the container or garden grown roses, thank goodness. And if I do a good jet of water spray appears to be the best cure.

A classic case maybe of different schedules for different places, that might be why most labels read spraying 7 to 14 days apart, my personal expereience seems to bear this out, oh if I could go 14 days. I agree with you that 14 days should work out but "Proof is in the pudding" and it seems I have a very soggy pudding.

It is fun to watch the tourists scatter around Waikiki, and other beaches; the locals know it will soon pass and sit it out, as the sun and wind will dry you of quickly. If you live higher up, as we do, it stays wetter for longer, possibly because it is cooler, being 78 F versus say 84 F.

I do not know whether or not this makes the BS, etc. more prevalent, but just a thought.