Daconil on spruce?

[WNC Bonsai]

So recently I was watching a Ryan Neil video on YouTube (BSOP Spring Fundamentals) and in his discussin of fungicides he was adamant that Daconil should never be used on spruce and instead suggested using Mancozeb for needle cast. However in looking at a number of websites, and a lot of them ag and university sites, they readily suggested using Daconil on spruce. Even the label lists it for use on pines, Douglas fir, and spruce. So now I am a little confused, why was Ryan Neil so adamant about not using it in spruce? Has anyone had any problems using it on spruce? I have a coulpe Norway spruce and one Col. blue spruce that I need to treat soon and don’t want to mess them up.

 

[0soyoung]

Branches are largely autonomous, so you could spray the end of one and see if whatever you are contemplating applying to the entire tree is trouble or not.

However, most fungicides work only on specific pathogens and therein may lie the reason. You might want to peruse this document (Daconyl = chlorothalonil). There is possibly something similar from the Ag department in North Carolina that reviews fungal pathogens specific to your area.

 

[Wires_Guy_wires]

The type of needle cast that affects spruce is not the same as in pines. Needle cast seems to be a general name for fungal pathogens affecting needles in conifers.
Pines are affected by cyclaneusma, spruce are affected by both rhizosphaera as well as stigmina needle cast (at least, that's what a quick google search threw up). All three are different fungi with different genetic make ups. This means that they might evade the mode of action of daconil due to them not having the 'code' that becomes dysfunctional by the chlorothalonil. For antibiotics to work, a pathogen has to have some mechanism that gets disturbed by said antibiotic. If that's not the case, it's just chemically contaminated water you're spraying on your trees.

 

[PiñonJ]

So recently I was watching a Ryan Neil video on YouTube (BSOP Spring Fundamentals) and in his discussin of fungicides he was adamant that Daconil should never be used on spruce and instead suggested using Mancozeb for needle cast. However in looking at a number of websites, and a lot of them ag and university sites, they readily suggested using Daconil on spruce. Even the label lists it for use on pines, Douglas fir, and spruce. So now I am a little confused, why was Ryan Neil so adamant about not using it in spruce? Has anyone had any problems using it on spruce? I have a coulpe Norway spruce and one Col. blue spruce that I need to treat soon and don’t want to mess them up.

He stopped using it on spruce a few years ago because they changed the formula so that it doesn’t wash off (I think the additive is called Weather Stick). This resulted in phytotoxicity to the needles.

 

[WNC Bonsai]

He stopped using it on spruce a few years ago because they changed the formula so that it doesn’t wash off (I think the additive is called Weather Stick). This resulted in phytotoxicity to the needles.

Thanks, now that makes sense. He was quite empharic about using Mancozeb instead of Daconil so I figured there was a specific impact he had seen from using it on spruce. I now own bottles of both amd am about to do the prophylactic spring applications once this cold spell passes and the buds start to move. I wonder why there is a phytotoxic effect on spruce but not other confiers? Also I thought Daconil with Westherstick was only available for use in nurseries and the red bottle variety available to consumers does not contain Weatherstick. I just read the EPA approved label for the Weatherstick variety and it does warn DO NOT APPLY to Blue Spruce.

 

[PiñonJ]

Maybe he had the nursery variety, I don’t know. If you’re a Mirai Live member, that would be a good question for the forum Q+A.

 

[WNC Bonsai]

Maybe he had the nursery variety, I don’t know. If you’re a Mirai Live member, that would be a good question for the forum Q+A.

Sorry, but my pockets aren’t that deep!

 

[coh]

Maybe he had the nursery variety, I don’t know. If you’re a Mirai Live member, that would be a good question for the forum Q+A.

I asked about that during a Q&A when I was a tier 3 member. I use a version of "daconil" called "fungonil" (by bonide) which has the same active ingredient (chlorothalonil) but doesn't appear to
have the same spreader/sticker. He wasn't familiar with the product but suggested testing it on a branch or stock plant to see if there is any toxicity. I've used it on pines, junipers, elms without any
problems. Don't think I've had to use it on spruce.

 

[PiñonJ]

I asked about that during a Q&A when I was a tier 3 member. I use a version of "daconil" called "fungonil" (by bonide) which has the same active ingredient (chlorothalonil) but doesn't appear to
have the same spreader/sticker. He wasn't familiar with the product but suggested testing it on a branch or stock plant to see if there is any toxicity. I've used it on pines, junipers, elms without any
problems. Don't think I've had to use it on spruce.

While living in a dry climate can be hard on trees, one great thing about it is that I’ve never had a need for fungicide!

 

[WNC Bonsai]

The main difference between Daconil and Fungonil seems to be in the concentration of propylene glycol in it. Daconil has about 70% and Fungonil <5%. Both have the same anount of chlorothalonil 29.6%. Not sure what it does in this case but it is used in some paint to extend drying times and also prevents chemicals applied to skin from pulling moisture out of the skin so maybe that is its intended purpose on plant tissues too.

 

[coh]

The main difference between Daconil and Fungonil seems to be in the concentration of propylene glycol in it. Daconil has about 70% and Fungonil <5%. Both have the same anount of chlorothalonil 29.6%. Not sure what it does in this case but it is used in some paint to extend drying times and also prevents chemicals applied to skin from pulling moisture out of the skin so maybe that is its intended purpose on plant tissues too.

There appear to be a number of daconil-type products and I don't know exactly which one Ryan was using. I know he mentioned "Weather stik". Some of those have higher concentrations of the active ingredient, over 50%. I looked at some of the labels and they consider the amount of other ingredients (such as propylene glycol) to be "proprietary" so they don't tell you anything other than it is in there.

I think in the end, it is incumbent on the user to test any particular chemical on part of a plant or a stock/sacrifice plant to see how it responds. Probably a good idea to do the same whenever a new container is purchased as formulations sometimes change (I think that is what happened with the weather stik product), and cross-contamination can occur. Read up on the problems with benlate from about 25 years ago if you want a horror story related to fungicides!

 

[WNC Bonsai]

Yes, and the Weatherstick variety has 54% chlorothionil. The other sitcky part is a trade secret. So maybe it was the extra strength or maybe it was whatever the Weatherstick is or the effect it has on spruce. I would imagine that no matter the chlorothionil concentration it will be reduced when diluted in water for application. Which comes back to the Weatherstick action or activity.

 

[Mike Hennigan]

Ryan Neil has said specifically that it is the added “weatherstik” component that is problematic for spruce. As said by previous posters you should be able to find daconil by some brand name that does not contain “weatherstik” and you should be good to use it on spruce. Just make sure it doesn’t have that additive.

 

[WNC Bonsai]

Thanks Mike for that clarification. Must be some nasty stuff. I will try out the plain old red bottle Daconil I got at Lowes on one isolated branch just to see whether it does any damage. The label specifically includes needle cast on pines, Doug fir, and SPRUCE among the conifers diseases it is listed to treat.