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White Pine Blister Rust #841018

Asked July 17, 2023, 9:52 AM EDT

I have a home in Glen Arbor with plenty of White Pine Trees on our site. We have had to take out a few small trees which turned brown and now a few branches on some of the larger trees are turning brown. My tree service said we have White Pine Blister Rust and has proposed quite an expensive and extensive root nutrient proposal to take care of this. When I read about it - it doesn't sound like there are really any cures. #1 - how do I know that is what our trees have? #2 - Are there any cures or treatments to stop it from spreading? #3 Any evidence that a root nutrient program would help prevent this disease? Thank you.

Leelanau County Michigan

Expert Response

Hello and thank you for your question. Could you please attach some pictures of the trees so that our experts can help identify possible solutions to your problem?

Thanks,
An Ask Extension Expert Replied July 17, 2023, 11:02 AM EDT
I already trimmed off all the dead and yellow branches so they all just look like healthy white pines- I won’t be there until Wed but I’ll send photos then

Sent from my iPhone

On Jul 17, 2023, at 11:03 AM, Ask Extension <<personal data hidden>> wrote:


The Question Asker Replied July 17, 2023, 11:07 AM EDT
Please send photos as soon as you can, Pat.
Thanks,
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Here are the photos

The Question Asker Replied July 21, 2023, 10:57 AM EDT

#1 - how do I know that is what our trees have? 

There are many possible causes for branches dying, from environmental stress to insects and diseases. You will want to carefully examine the transition areas between living and dead needles on branches, looking for signs of insects or cankers. A good explanation of what to look for in the case of blister rust is available here: https://www.canr.msu.edu/news/white_pine_blister_rust_damage_showing_up

#2 - Are there any cures or treatments to stop it from spreading?

For white pine blister rust (which I'm not at all convinced you have), removal of infected branches and elimination of ribes (alternate host) is pretty much the most you can do. The use of fungicides on smaller trees can help, but it requires a regular spray program, and is not practical for larger trees. It is also nearly impossible to spray the entire tree, including all needle and branch surfaces. There are a few trunk-injectable products, but they do not perform as well as the spray products. Although most infections occur within the lower third of the canopy, the entire tree has to be sprayed, or the infection will likely jump higher in the tree. The sprays would also need to be repeated a minimum of four times per year, indefinitely. If the trunk becomes infected, there is no cure for your tree. Fungicides cannot cure any infection; they can only prevent the spread. This is true even of systemic fungicides. The infection will eventually spread around the entire trunk, and everything above the canker will die. 

#3 Any evidence that a root nutrient program would help prevent this disease?

No. You could apply a low dose of nitrogen fertilizer (1 lb N / 1000 sq ft) to give the trees a bit of a boost, but I would not recommend a deep feed or other extensive program. These trees are adapted to nutrient poor sites. If you apply nitrogen, slow release is preferred. Organic sources should be applied in late winter, but inorganic sources should be applied in late spring after the first flush of growth. 

You could consider getting a soil test, which would let you know the soil pH (acidic for pines) and whether there are any nutrients lacking: https://homesoiltest.msu.edu/.

Thank you for contacting Ask Extension! Replied July 25, 2023, 11:07 PM EDT

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