Treatment for Need Blight (Dothistroma)

[doipac]

Greetings folks,

I’ll start by saying that I’m a big fan of needle blight, which I’ve had the privilege of studying over the past 3–4 years. This “blessing” wiped out my entire collection of pines one by one—everything from JBP, JRP, JWP, Nigra, Mugo, Sylvestris, Peuce… you name it.
Without going into too much detail, I can say I’ve learned a lot. In fact, I could probably write a damn book about it. If anyone needs help with identification or some prevention advices, I'm here for you.

The only thing I haven’t been able to figure out is how to treat it effectively. And by that, I mean the right fungicide—not the safety measures and prevention steps, which I’ve already been following.
As those familiar with blight know, copper fungicides are ineffective against it, and I haven’t been able to find a proper treatment since the EU has restricted most of the alternatives for broader use.
I know this is a serious and widespread issue, and I’m sure those with larger pine collections have faced it as well. If anyone is able to share a solution, I would be deeply grateful.
Since this is a sensitive topic, I’d also welcome private messages—even anonymous ones.

Thanks a lot!

 

[The Barber]

I was going to chime in with the gauntlet of fungicides we use here in the states...but I would wager most are banned there now. Hopefully someone from the UK will chime in with some help.

 

[Wires_Guy_wires]

There is none.
Once you notice the infection, you can kill the surrounding mycelium but the spore-forming body has already enough energy to grow and reproduce stored in some truffle-like structures.
I think the best analogy is that you have an amputated foot in the fridge that starts rotting. You can take all the antibiotics you want, but that's not going to prevent something that is no longer connected to your body from spoiling.
Soapy water can make the hydrophobic spores hydrophilic, and wash them down.

The key is prevention.
I'm pretty against broad spectrum antibiotics, but more so the users who use it carelessly and spray it on everything for everything. But I am also a human being that cherishes things that sometimes require some extra protection. If that means importing antibiotics from China or elsewhere because they are banned here, I will. I just make sure they do what they should, and that I'm not accidentally making a more resistant strain of fungus in the process. For a time, microbiology was my bread and butter so I'm usually quite motivated at finding out of the box solutions. But I acknowledge that sometimes you need the big guns.

For needle blights, I haven't been able to find anything, other than ramping up the mycorrhizal community and hoping that they supply the plants with ample antibiotics to prevent it all together. And it seems to be working in my case.

If you can share your location, I might be able to send you some soil samples containing the fungus that prevents it in my plants. I water overhead all year around and my pines have about ten to twenty affected needles (if any), but no more than that. And I haven't been doing anything preventative for about 5 years now. The fungus is picky, it requires some forest soil and some leaf litter (about a tablespoon) and akadama (two tablespoons, probably for minerals) to get going, but once it takes hold it will colonize the pot quite rapidly.. In about a season. From there you should be able to "graft" it into other pots.

Other than that, yeah.. No, I don't really have a clue.
But needle blights wiping out your entire stock do hint towards a larger issue. Even in poor health nature patches, we see that it almost never kills a whole plant. Maybe your water source is the issue, or you're re-using something that you shouldn't.

I'm also arriving at a point where I'm starting to believe in some immune system priming for plants; expose them to light amounts of pathogens or breakdown products of pathogens to set the plants up for defense. For instance by adding a little bit of needle mulch to the soil. When you think about it: once those needles drop, something can and will eat that fungal body, as is the law of nature. Having that specific mystery organism inside your soil already might cause it to flourish and set your plant up with the proverbial turrets.
They say that for every organism, there are a couple hundred viruses. I believe it's the same when it comes to organisms in relation to fungi, bacteria and archea and even amoebas and such. Something at some point made a living out of eating it. It's up to us to find them and make sure they thrive as a commensal organism.

I have tried a bunch of illegal antifungals in the past and I can wholeheartedly say that because of the physiology of a pine needle and the fungus itself, there is no cure in the sense that you can heal a needle back to normal. Amputate the affected needles below the bands, and you can keep a part of the needle for photosynthesis and recovery, while at the same time limiting re-infection. Dip the cut needles in soapy water before burning or discarding them and keep the soil alive as a biome instead of a medium. I discovered my mystery mycelium by accident, I did not identify it nor do I plan to do so. But it seems to be transferable. That means it's widespread throughout mainland Europe.. It has to be. Go dig around in the woods, look for grey colored mycelium that's fluffy and likes dry patches of soil. Any wild pine stand should probably have some near the root base of young trees.
Whatever it produces, it's helping.

PS. I reject the notion that mycorrhizae are non-transferable. Any mycologist who says so, does not understand biodiversity and evolution and I'm willing to debate them.

 

[johnl445]

I was going to chime in with the gauntlet of fungicides we use here in the states...but I would wager most are banned there now. Hopefully someone from the UK will chime in with some help.

Actually, I’m in the US. I’d love to learn what fungicides you recommend for needle blight. I’m sure there’s a rotation needed to avoid the tree developing resistance to fungicides.

 

[bwaynef]

I responded to another thread today about Dothistroma. Phyton 27 (& 35) list it among the pathogens it (they) control.

 

[Bonsai Nut]

As those familiar with blight know, copper fungicides are ineffective against it

I have never heard this before - in fact, topical fungicides including copper are listed here in the US as being highly effective against it. You obviously can't cure infected needles, but you can keep new needles from getting infected. It is important to treat trees in the spring before they are heavily infected.

Mancozeb is probably the most popular non-copper topical anti-fungal that is specifically listed as being effective against Dothistroma... though I'm not sure it is available for sale in Europe.

https://www.fs.usda.gov/foresthealth/docs/fidls/FIDL-143-DothistromaofPines.pdf

 

[The Barber]

Actually, I’m in the US. I’d love to learn what fungicides you recommend for needle blight. I’m sure there’s a rotation needed to avoid the tree developing resistance to fungicides.

This may sound like a lot, but I have never seen needle cast on any trees in my friend's pines, and he has a lot of them. Kentucky is very humid, and most people here constantly have to battle it. This is the regiment he uses that I'm

Sprinkle Cleary's granules on soil in March (it is safe for mycoriza in the soil). Liquid copper when cool in April and September, then Mancozeb 2 weeks later after copper, then Phyton 35 mixed with seaweed and superthrive and a little all purpose fertilizer, then 2 weeks later Clearys 3336 mixed with a little seaweed and super thrive and gen purpose fertilizer 2 weeks later, then Daconil 2 weeks later not mixed with anything then start over at mancozeb until last copper spray in cooler part of late September. Then lime sulphur spray late October. Nothing until spring and start over.

 

[bwaynef]

Mancozeb is probably the most popular non-copper topical anti-fungal that is specifically listed as being effective against Dothistroma... though I'm not sure it is available for sale in Europe.

https://www.fs.usda.gov/foresthealth/docs/fidls/FIDL-143-DothistromaofPines.pdf

The label below for mancozeb doesn't have the word "Dothistroma" in it.

Mancozeb Label​

DoMyOwn
https://www.domyown.com › msds › Mancozeb-L...

 

[doipac]

Thanks everyone for your posts. Was actually able to find Mancozeb in Serbia, so I think it's safe for now.