Rust on my blueberries?

Would anyone have an idea of what is causing the leaves to do this ? Maybe rust?

I believe I’m seeing deficiencies in Copper, Zinc (Bacterial spot) and Iron (Chlorosis).

In my experience, foliar treatment is the most effective way to halt the progression. I would use Iron EDDHA and Zinc, Copper EDTA. Some manufacturers sell a single bag of all three plus a few other micronutrients in dehydrated form. Blueberries can be sensitive – do not overdose!


Thanks Richard! Would you have any idea where I might find some of that ?

I’d say there is some disease. But this time of yr that’s probably normal in your climate. There’s also iron deficiency caused by media pH being too high. The plants are also nitrogen deficient. If these are in-ground then I’d apply a tablespoon of ammonium sulfate dissolved in 5 gal of water to each plant about every two weeks. That will supply nitrogen and lower pH. If in pots it’s another story.

The wet weather you’ve been having causes foliar issues and leaches out the nitrogen.

What’s the pH of your soil?

My soil samples I sent to LSU in Feb. came back with a PH of 5.3 . And yes, they’re in ground and have had tons of water with that recent weather.

At that pH you should be OK. I’d apply the AS some now and more next spring. Your plants appear to be lacking in foliage and new growth. But that could be only a partial view. On second look the bottom picture shows some good looking, dark green foliage.

I’ll have to pick up some more ammonium sulfate , but I do have some soil acidifier + Iron I can give them. The PH has probably came up over time.

They are widely available from agricultural suppliers.

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Septoria Leaf Spot or Anthracnose may be causing those problems.
Here is something from North Carolina State about those things.
The third photo does look somewhat like an iron deficiency issue. Brady

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Copper and Zinc.

Could be copper and zinc, along with iron and maybe other micros. But one doesn’t cure that by applying chelated nutrients multiple times every yr. It’s solved by correcting the pH to ~4.5. At the correct pH level there will be no micronutrient issues even on a nutrient poor media like bark fines or spaghnum peat moss.

Here’s what my blues look like at correct pH in pots with nutrient poor media and mainly just nitrogen as fertilizer.

This plant is 6ft by 6ft in a 12 gal pot and 7 yrs old.

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I’m going to take a soil sample today and send it off Tuesday. That way I can take the guess work out of it.
Instead of getting the basic test , I’ll opt for the full test.
I’m going to guess that the PH has came up a lot from 5.3 .

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Another point, It’s during the wet spells that iron deficiency symptoms spike. Our plants can look great in summer. But give us a good rainy spell, 4-6 inches in a month, and the new growth often turns almost white with iron def.

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I see your point. Once I get the soil results I’ll post them for your thoughts.
That blueberry plant pic you posted looks great!! Looks like a sweetcrisp.

You’re right fruitnut, here’s a pic I just took of some sweetcrisp , and you can see the new growth is extremely light .

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Nice greenhouse :smiley:

Looks like a Star to me. And by my expert estimate, it is 10+ years old!

I agree the pH must be correct. I did not propose applying chelated nutrients multiple times every yr. Rather, once the condition is present foliar spray is very effective halting the progression. Cure? – no.

Just got the soil sample results back. What do y’all think? I understand the PH but that’s about it!:thinking:

Looks good for blueberry. All I’d do is apply enough nitrogen to get the growth you need. At 4.7 pH I think you could use ammonium sulfate. But if you don’t want to lower the pH use urea or an organic source.

On second thought I should ask what have you done so far to lower pH? And what is the native pH?