Not HVX symptoms

Hank Zumach · Post by **Hank Zumach** » Jun 18, 2008 1:59 pm

Hi--I'm thought some of you might be interested to see the photos of plants that I just tested for HVX, using the new test strips. The results were negative, which was a nice surprise to me because the plants showed the same kind of spotting that indicates HVX. The first photo is of Sum & Substance and the second is from Roy's Pink. Does anyone know what might be causing these spots?

Hank Zumach

Hank Zumach · Post by **Hank Zumach** » Jun 18, 2008 2:01 pm

I guess I've been lurking too long and don't know how to add a photo anymore.

Here is the photo of Roy's Pink

Post by **Chris_W** » Jun 18, 2008 2:58 pm

HI Hank!

Nice to see you

The first picture might be from frost damage. If wet ice crystals settle on a leaf it can cause that kind of damage - wet ice is 32 degrees. Not enough to completely "burn" through but enough to cause light spotting.

The second picture really looks like some kind of virus. It isn't HVX, as the test strip indicated, but there are many other types of virus in hostas, and this unfortunately is a different one from HVX. Maybe tobacco rattle virus, or tomato ringspot virus? You might need to pay to have it checked for all types of viruses to find out which it is, but the prognosis is the same - pitch it to prevent it from spreading.

If you did get it tested you could send the other to double check. The University of Minnesota would test them for me last year by electron microscopy if I paid enough. Not sure how much they are charging this year for that, but this way they can screen for all viruses, not just HVX.

Sorry to be a downer, but good to see you

Chris

Carol W · Post by **Carol W** » Jun 18, 2008 7:57 pm

Hank,
Last year late fall I used this http://www.extension.iastate.edu/news/2 ... 071502.htm
And not only did they test for HXV but for 4 or 5 other hosta virus including 2 of those Chris mentioned tobacco rattle virus and tomato ringspot virus. Within a few weeks they called me to let me know that the plant was clear of the other hosta virus except HVX and they were waiting on the HVX test to be completed. The result were 100% yet but they were almost sure it would test 100% positive. Later when the whole testing was complete I received a letter from them with the complete testing results and yes it was positive for HVX.

Hank Zumach · Post by **Hank Zumach** » Jun 19, 2008 11:24 am

Thanks for the comments. The Sum & Substance is 14 years old and in its location for most of that time. Roy's Pink was a gift in 2002 and has been in its location since then. They are about 50 feet away from each other. There are no other plants of any genera near them that have any symptoms. If a virus is involved, how could the plants have become infected?

If the Roy's Pink plant has tobacco rattle virus, which is spread through nematodes, could I stop any spreading by using disyston in the area?

I did a google search but its hard to understand what can be done to combat the tobacco rattle virus.

Post by **Chris_W** » Jun 19, 2008 11:41 am

Hi Hank,

I don't think Roy's Pink has a virus, but it would need further testing to be certain.

Viruses can spread by quite a few different ways - weeds can even carry viruses and then insects like aphids can spread some of them.

I would strongly recommend contacting the University of Minnesota Plant Disease Clinic:

http://pdc.umn.edu/

Chris

Hank Zumach · Post by **Hank Zumach** » Jun 19, 2008 12:00 pm

HI Chris--I just called the UM lab and they charge $37 per sample to have a electron microscopy test done. Right now I'm inclined to destroy the Roy's Pink (it has a lot of other spotting on other leaves that I didn't try to photograph).

The S & S is 14 years old and I'm really reluctant to destroy it. I probably will wait to see if the symptoms start to show up on other leaves and then decide what to do.

Thanks for your help.

kontyx · Post by **kontyx** » Jun 19, 2008 1:55 pm

As for the Roy's Pink, my money is on TRV (Tobacco Rattle Virus). I have seen a few samples come through our testing lab with identical symptoms test positive for TRV. On the other hand though, if I had to make a second guess then it would be ArMV (Arabis Mosaic Virus).

Rosenzobel · Post by **Rosenzobel** » Jun 20, 2008 2:04 am

I guess it is tobacco rattle virus- I also have got a plant with symptoms like that- the bad thing is- i can´t find any good pictures with TRV infected plants in the net!....i found hundrets of HVX photos but only 4 or 5 photos with tobacco rattle...

Has anybody got some more photos of that desease and what to do when 1 Hopsta has got the virus?? I also think that my Epimediums has got the virus too....;-(

greetz

kontyx · Post by **kontyx** » Jun 20, 2008 11:54 am

Here is a picture that i scanned. These leaves tested positive for TRV in real time-PCR. If you want a closer shot of the symptoms, just let me know.

Kas · Post by **Kas** » Jun 20, 2008 12:37 pm

A couple of years back I had several with weird looking spots like that. I sent them to Dr. Lockhart and they all came back negative for any virus. And they were scary looking! The next year they looked just fine. Go figure.

Kas

Rosenzobel · Post by **Rosenzobel** » Jun 20, 2008 12:49 pm

thakn u so much for the photos- looks a bit different to my plant:

but i guess my one also has giot TRV...;-(...Now , that the leaves are bigger some more of them show very small symptoms like the one on my pics above....
So- what to do???

if you have got a closer shot- it would be great!!...thank u again!
greetz mel

Ginger · Post by **Ginger** » Jun 20, 2008 1:01 pm

That yellow spot looks like sunburn to me

Ginger

thehostagourmet · Post by **thehostagourmet** » Jun 20, 2008 2:09 pm

I agree with Ginger. It looks like sunburn to me too. Are there more leaveswith the same symptom?

kontyx · Post by **kontyx** » Jun 20, 2008 2:18 pm

here is a close up of the symptoms.

Hallson Gardens

Not HVX symptoms

Not HVX symptoms

Virus?