B.v.Vittata shoot damage. What's causing this problem?

[Agrobambu]

Bamboo people
I am with a new problem with my "vittatas".
http://www.bamboocraft.net/bamboo/data/518/thumbs/359Vittata_disease1.jpg
Bambusa vulgaris `Vittata' (http://www.bamboocraft.net/bamboo/showphoto.php?photo=880)

Last Dec/20 I saw a little spot in some culms of my bamboos.One week after this spot had +/- 2 x5 inches covered with a sheath ( the sheath was detached).
Under the sheath it had a dark color brown with a yellow powder, characteristic of a fungus.
http://www.bamboocraft.net/bamboo/data/518/thumbs/359Vittata_disease_3.jpg
Photo #2 (http://www.bamboocraft.net/bamboo/showphoto.php?photo=882)

http://www.bamboocraft.net/bamboo/data/518/thumbs/359Bamboo_-_Vittata_dese_6718C.jpg
Photo #3 (http://www.bamboocraft.net/bamboo/showphoto.php?photo=881)

At this time here in south of Brazil it is very hot 25ºC at night and near 40ºC under strong sunny days. No rain about 45 days. The ground its very dry. It is difficult to water the area where the bamboos are. One or twice a week I do it. I don't know if this dry period has some influence in this case.
Some culms are not infected yet and have new sprouts comming at this time
I'm afraid that they may become infected.
http://www.bamboocraft.net/bamboo/data/518/thumbs/359Vittata_Disease_4.jpg
Photo #4 (http://www.bamboocraft.net/bamboo/showphoto.php?photo=883) - How to prevent this?
I have a group of others bamboos species and I can see the same case at the
D.giganteus culms too, including they are with sprouts coming.
If someone had this experience and know what to do please contact with the forum or email me (bamboofount@terra.com.br).
The pics above have near 2 weeks.
Joseene/Brazil

[Mark Meckes]

Just to be sure... can you double check to see if there are any scratches or any markings on the surface of the culm that may have been caused by any animal trying to get at the shoot when it was emerging?

You would also see some evidence of tears and scratches on the sheath that protected the shoot, if this were the case.

Somewhere to start...

Mark

[Agrobambu]

Mark
Thanks, about your suggestion. I know you mean, but I saw this poles growing up perfectly looking day by day since they are sprouts and I'm sure this problem have a another origin. This problem we can see including at the higher part of the poles were before the culm was perfect.
This weekend(jan/16) I was looking better and the situation is getting worst. I 'm afraid to lose all culms ( the oldies with 2 1/2 years and the new ones are emerging now).
Have you seen this before? If someone read this post and knows something about this stain (pics), please contact me here or directly to my email. (bamboofount@terra.com.br)

[Mark Meckes]

Have you checked the source of the parent plant where you got the starts for your plants, to see if they also have the problem?

I would also suggest that you contact your local/regional agricultural office for assistance.
Email them a link to this thread, so that they can see the pics you have provided.

Mark