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Help with raspberry problem- disease or fungus?

Posted by Roserobin PNW 8 Canada (My Page) on
Mon, May 16, 05 at 16:18

I have a nice patch of thornless raspberries that have grown and fruited well the past 2 years and sent up new plants. This spring, some of the canes have developed a problem, the leaves turning brown and shriveling, and the cane also looking brown, after flowering and forming unripe fruit. I am afraid it might be spreading to whole patch, so I have removed these canes. Anyone know what might cause this and what the remedy is? Doesn't appear to be a bug that I can see, behaves more like a fungal problem.


Follow-Up Postings:

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RE: Help with raspberry problem- disease or fungus?

I have this problem too in canes I got from my MIL. Hers are still fine. Basically a big stand of raspberries is now gone as a result. One other variety, Willamette, shows some signs of this too. I think different cultivars have degrees of susceptibility to this problem, so I planted a number of different raspberries to see which does best, as I don't like to spray. Maybe someone else knows the particulars of this disease.


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RE: Help with raspberry problem- disease or fungus?

Without seeing the plants it's difficult to make an accurate diagnosis but raspberries are susceptible to verticillium, which has symptoms much like you describe. Removing and destroying the plants is recommended, however replanting with new plants in the same location is risky and excessive disruption of the root zone of adjacent yet unaffected plants also puts them at risk. Best to take a sample of the affected plants, roots and all, to your county extension office for a proper diagnosis. They will advise you how best to proceed


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RE: Help with raspberry problem- disease or fungus?

I don't know the name of the cultivar, I got a package of 4 canes at home depot 3 or 4 years ago, and was surprised and delighted to find it was a thornless variety. It has spread into a reasonable patch and we had a very nice crop the past two years of big tasty raspberries. It sounds like the remedy for this is similar for fungal diseases for roses (dormant spray, sulphur or copper, disease resistant varieties.) There was no sign of any disease before this year, so I didn't think there would be a problem. The canes made lovely new leaves and flowered and formed fruit, but then the leaves started turning brown and withering. Not sure which disease it is, hope I can get it under control...


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RE: Help with raspberry problem- disease or fungus?

It is some type of root-rotting pathogen in your soil; you have the same symptoms and timing as I did; two years, all is fine, and then gradually the patch goes sour.

Once this is in your soil, it takes several to many years for it to go away. I tried re-planting raspberries from my neighbors yard 20 feet away. They were in heavy clay and deep shade, but still fruited. In my yard they died the second year.

It will take a soil treatment to cure this. Some of the State Experimental Stations are working on the problem.


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RE: Help with raspberry problem- disease or fungus?

Gardengal, I must have posted my previous response at the same time as you. It sounds like you think I may need to remove the entire patch and relocate my raspberries.

Someone on the fruit forum posted this link; it may be (I hope)something else, as only the leaves seem to be affected so far, though the canes become brown eventually as well.

Here is a link that might be useful: raspberry diseases


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RE: Help with raspberry problem- disease or fungus?

Phytophthora root rot is a likely cause; it fits the timing and symptoms. Armillaria root rot is another; it is usually accompanied by little mushrooms.


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RE: Help with raspberry problem- disease or fungus?

  • Posted by jean001 z8aPortland, OR (My Page) on
    Fri, May 20, 05 at 1:26

Root rot -- by the fungus Phytophthora -- resides in the soil. The telltale symptom: the fruiting stems die.

A second fungus kills raspberry canes also. In this instance, it's a vascular wilt -- by the fungus Verticillium -- and kills the canes in their first year of growth.

So, I'd say that it's the root rot that is killing Roserobin's plants.

And here's the really bad news:
-- Both the above fungi reside in the soil.
-- No spray is helpful against either disease.
-- No soil treatment is available to get rid of either of these fungi.
-- The fungi will remain in the soil for many years.

The only thing a gardener can do is to plant NEW raspberry plants in a NEW site. Do so in a raised bed -- the extra height assists soil drainage.

Caution: Don't move an apparently "healthy" plant from the affected site to anywhere else in your garden. This because you will also move the disease-causing fungus. Not a good thing.


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RE: Help with raspberry problem- disease or fungus?

Brand new Coho plants I put in this year in an area where no raspberries have grown but infested with blackberry vines, are developing brown areas in the new leaves.:-( This doesn't look like the same problem as the other raspberries.

My other raspberries are:
Willamette
Chilliwack
Newburgh
Amity
Latham
Fall Gold
Meeker

I'm hoping among them are some that will grow well without disease. I have a large stand of Chilliwack
that seems to be OK so far.


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RE: Help with raspberry problem- disease or fungus?

I should mention that black-caps and a variety of thornless blackberries grown in the same spot (as the long-dead red raspberries) for several years have been totally unaffected.


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RE: Help with raspberry problem- disease or fungus?

I agree with Larry and Jean, Phytophthora is the most likely culprit. What kind of soil are they in? I would guess that it's not very well drained. You rarely see Phytophthora in sandy soils with good drainage.


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RE: Help with raspberry problem- disease or fungus?

I put lots of amendments in my berry patch prior to planting--nearly two feet deep with sand, pumice, etc.

Water does not pool there. The Phyto must have been in one of the amendments.

The neighbors raspberries are in heavy clay, deep shade and no care whatsoever, they do fine.

So, red raspberries can be croaked in well-drained soil.


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RE: Help with raspberry problem- disease or fungus?

  • Posted by jean001 z8aPortland, OR (My Page) on
    Fri, May 27, 05 at 1:39

It was said:
"The Phyto must have been in one of the amendments."

Possible.

It can come on the plants, also, particularly if you obtained plants from someone else's garden.

And very likely is that the Phytophthora is widespread in the soil of gardens and landscapes throughout this region.


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RE: Help with raspberry problem- disease or fungus?

anyone care to take a stab at identifying this stuff (aphids?) on my raspberry plants. These are first year plants in New York, for what it's worth.
Treatment suggestions would also be most welcome.

Here is a link that might be useful: look if you dare


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RE: Help with raspberry problem- disease or fungus?

  • Posted by jean001 z8aPortland, OR (My Page) on
    Tue, Jul 12, 05 at 17:56

Midwood,

Difficult to say for certain.

Take a sample to a local large independent garden center or farm store.

Beyond that, a suggestion for you:
When you have a question that's different from the current thread, begin a new thread of your own with your own subject line. That way, you're more likely to get more replies.


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