The cause & treatment?

[Crazy4Clems]

Malgorzata, I can check on the others, but I'm sure that Dakoni-RU 1000 on your list is Daconil here in the U.S. It is also widely recommended here as a general purpose fungicide. The active ingredient is Chlorothalonil.

[Paul]

DAKONI-RU 1000
This is the equivalent of the trade name Daconil and contains chlorothalonil
It is not active against powdery mildew (but has protective activity against the wilt fungus)

SAPORORU
It contains the active ingredient triforine. It is active against powdery mildew but it is an old product and resistance to it is common in the powdery mildews.

PANCHYO TF
Sold as Pancho TF outside Japan. It is a mixture of two fungicides, one very recent, which are active against powdery mildew. This is the one to use but you must apply it correctly re timing.

BENRE-TO
This is benlate. There is widespread resistance and is of no value anymore (now banned in most countries on health grounds)

STREPTOMYCIN
This is an antibiotic for bacterial diseases. It has no activity against fungi.

[Malgorzata]

Thank you! I am trying to Google it now. How did Chlorothalonil became te-to-ra-ku-ro-ro-i-n-fu-ta-ro-ni-to-ri-ru?!

[Malgorzata]

Paul, should I cry?!
Ok, I have one preventive and one "working" fungicide so there is hope. When to start the fight? Now? When it cools down? Still 34C during the day. In winter? Do I use once Daconil and next time Pancho TF or do I mix them in the same application? How would you proceed? Thank you!!!!

[Malgorzata]

I really need help with this one. I know how important it is to read the labels (I can't read kanji so I always ask stuff to instruct me how to use certain chemicals). Now I had my husband reread the label on Pancho TF. Apparently there isn't anything about reapplying other than up to two times for fruit and up to 5 times for roses. But how many days in between?!
This is the translation of "How to apply" Pancho TF that I found on the net. Can you find how many days between the sprayings? may be we are missing it? I was told every 5 days or so. For roses every fortnight for three times...
Hope the link works. Translation Thank you!

[Paul]

Originally Posted by Malgorzata How did Chlorothalonil became te-to-ra-ku-ro-ro-i-n-fu-ta-ro-ni-to-ri-ru?!

= tetrachloroisophthalonitrile, the chemical name (chlorothalonil is the common name, Daconil the trade name)

Originally Posted by Malgorzata When to start the fight?

1. Prune when the plants are dormant in winter.
2. Start sprays against powdery mildew in spring when shoots are about 15cm long and temperatures have reached 15°C. I start mine in mid April and apply 3 sprays at 10 day intervals, you may have to apply more. If you need to spray against rose black spot, you can use the same fungicide and the same timing.

Don't worry about using Daconil for wilt, I just mentioned it out of interest as I saw it had activity in a laboratory study. In principle, a spray of dormant plants before they start shooting should prevent spore production which occurs on the old wood. Protective sprays on the new shoots and leaves during spring should prevent them from getting infected by spores. This has not been tested in the field as far as I know.

Daconil will not provide any control of plants that are already infected at the stem base or on underground parts - the infection sites that give rise to typical wilt symptoms.

[Crazy4Clems]

Ah, Paul already responded with the other names. Malgorzata, I'm in a similar zone to you, but in southern U.S. I imagine we have similar humidity, and thus similar fungal issues as well. I start my spray routine at the same time Paul mentioned, but when the plants first break dormancy, I use a 7-day regimen as opposed to 10 days. I also provide 5 sprays rather than 3.

[Malgorzata]

Such informative answers! Thank you 100x100! I would never get to the bottom of this by myself. I do hope Pancho TF will do the job. It looks like I should dispose with the others. It is not just about this one Clematis now. I knew from experience the fungicides available to me in the stores were generally good for nothing after mildew showed up but somehow I am still "surprised" why those "old" (and expensive) chemicals are the only ones available in gardening stores around me. Then Daconil is recommended on every rose lecture I went to followed by "Sapororu". But then here things are very different "up front" and "behind". The "real" secrets are protected and seldom shared with too many.

Paul, THANK YOU! Thank you for sharing your knowledge and taking the time. I really appreciate your help.

Crazy4Clems, so glad you joined our site!

Peer, thank you for pinpointing the problem! What an eye!

Helen, Deborah, thank you for your insight!

It has been a very educational converation for me!
I am so glad that I have for now one "working" fungicide!
...and glad some Clematis Group 3 are still performing beautifully!

[Caramella]

Originally Posted by Paul If you need to spray against rose black spot, you can use the same fungicide and the same timing.

I want to add my thanks to you, Paul! Powdery mildew is not a problem in my garden, but black spot on roses is. I'll follow your directions using a Pancho TF spray next spring (if I can find one).

[peer_nz]

Originally Posted by Crazy4Clems I use a 7-day regimen as opposed to 10 days. I also provide 5 sprays rather than 3.

Using a modern curative fungicide are mostly recommended to use only 3 times in one season and if used late in one season it's adviceable to NOT use it again in start of next season in order to avoid build up resistance to the active ingredients, overuse are our largest problem, it take time to develop new products and proper use make them work longer. So do not overuse or over dose!!!!!!!!!!!!!!!!
I'm just the concerned Nurseryman, Paul are the Plant pathologist so this is his field!