Browning leaves

plethora87June 13, 2011

Hello,

This is my first go-around with a canna. Is this the dreaded virus?


Thank you for reporting this comment. Undo
mantis__oh

Could just be rust. What sun conditions is the canna grown under? What do the newest leaves look like?

    Bookmark   June 15, 2011 at 7:27PM
Thank you for reporting this comment. Undo
plethora87

Hey mantis,

4 hours of sun per day. The newer leaves are okay but it seems to be getting worse overall.

Do you think I should remove the affected leaves?

    Bookmark   June 15, 2011 at 8:15PM
Thank you for reporting this comment. Undo
mantis__oh

I would remove the affected leaves. Seems like rust to me. Try spraying with something like Daconil. I had a Shenandoah that did the same last year. Four hours isn't much.

    Bookmark   June 16, 2011 at 9:24AM
Thank you for reporting this comment. Undo
canna2grow

One of problems is I could not determine where the canna is growing. This is often important because certain pathogens are more prevalent in specific zones. The necrotic symptoms appear to me to be more closely aligned with a bacteria leaf disease (specifically-bacteria leaf spot).
These symptoms could be the result of a virus infection but does not appear to be either CaYMV or CaYSV.
Canna rust (fungal) is most prevalent in the Southern areas of the U.S. but can occur further north but most often in late summer and the fall season. Rust always begins on the lower side of the leaf surface with the onset of red postulates. Rust is typically easy to diagnose by observing the underside of the leaf prior to necrosis.
If possible, it would be better if your plant received more hours of sun and prevent overhead watering late in the day. Wet foliage for extended time will augment the onset of both bacterial and fungal disease.
I cannot personally rule out any of the three possibilities.

Kent

    Bookmark   June 16, 2011 at 10:14PM
Thank you for reporting this comment. Undo
plethora87

Hey folks,

It's being grown in Northern Virginia. I don't have a spot with more sun available.

I'm surprised by all of this because the leaves have barely been wet at all over the last month and a half -- it has hardly rained, and when I water I don't wet the leaves.

    Bookmark   June 17, 2011 at 6:34AM
Thank you for reporting this comment. Undo
canna2grow

Plethora87,
I don't believe any of us can give you a definitive answer but even though you have had little rain or do not water the foliage the photo indicates that the lower leaves seem to be the most affected? Do you have dew in the mornings? If so, the lower leaves will be the last to dry. Your limited availability of sun would contribute to the possibility of the lower leaves remaining damp longer.
Do a search for "bacterial leaf spot" and compare the damage to your plants. Bacterial leaf spot is more commonly seen in field grown cannas where the soil splashes or is blown onto the plants lower leaf surface but it can be transmitted in other ways. It is not typically seen in container grown stock unless the foliage remains wet for extended hours. I have seen it in greenhouse seedlings and small cannas where the water collects in the whorl. I have observed this condition often in the field (growing in the dirt).
We still can not rule out rust, virus or even a combination of these problems.
Best of luck,

Kent

    Bookmark   June 19, 2011 at 1:41AM
Thank you for reporting this comment. Undo
plethora87

Thanks Kent! Very much appreciated. I removed the affected leaves and sprayed Daconil so we'll see what happens. I'll be more vigilant about keeping things dry as well.

    Bookmark   June 19, 2011 at 8:14AM
Sign Up to comment
More Discussions
Leaf rollers
I had one canna this year that had leaf rollers in...
goldenbuckeye
Looking for unusual cannas
especially with variegated leaves...have lots of tropicals...
Frank Flanagan
storage of cannas over winter
I have have over 50 cannas that were dug up winter...
notenoughtimepegster
canna fermentation to make ethanol
I have read that some farms are using canna rhizomes. Does...
dirtaddshp
Seedlings : Canna Musafolia 'Grande'
Just wanted to give a feedback. I enjoy sowing cannas....
sleuthtl73
© 2015 Houzz Inc. Houzz® The new way to design your home™