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Suitable fungicide - blackspot signs and preventative action


HugoMorse
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I just wondered what the most suitable fungicide is to deal with black spot. Doing a search in this forum, I have seen that other people have asked the same question, but it has not really been answered. Is there any active ingredient that is more effective than others?

Black spot can affect VFT's when there is excess humidity. Unfortunately, one of my plants is infected. With the weather being very wet and humid, I want to try and nip it in the bud (no pun intended) before it affects too many leaves.

Just to advise, the signs are:

Newly forming traps turning black before they develop

Black spots appearing on leaves (i.e. in the center)

The leaves go black around the edges

This can spread to the white leaf base and affect the rhizome but is not fatal. The problem area can be cut out and the infection controlled.

This can be a common problem to terrarium growning due to the closed environment.

The ways to try and control it are (other than fungicide):

Increase ventilation

Reduce watering and allow the tray to dry out

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No, I am not certain, but everything I have read points towards it. It seems to occur in a very humid environment or from excess water.

Brad identified it as being black spot in Varun's thread (see the last post);

http://www.cpukforum.com/forum/viewtopic.p...ight=blackening

The other threads I was refering too are:

http://www.cpukforum.com/forum/viewtopic.p...ight=blackening

http://www.cpukforum.com/forum/viewtopic.p...ight=blackening

There are some others too, and there seems to be a similar mode of thought on the Terraforums. Other research seems to suggest the same.

The problem started to occur because I have had to water the plants more due to using Supersphag. I found that by letting the plants dry out before watering, the Supersphag was aborsbing water away from the roots of the plants and causing wilting of the traps and teeth. I only realised what was causing it from Brad's analysis of a problem some one was experiencing. I had originally though it was from too low humidty.

Supersphag is an excellent potting medium as it is so light and non-messy to work with and ideal for VFT's, but separate a piece and it dries within a minute, so has some major dissadvantages.

I may repot in the good ol' peat moss and water less, but would like recommendations on fungicides first.

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I have only ever experienced it with maintaining a higher level of water in the tray and from much higher humidity.

My plants all have a top covering of live sphagnum moss and I have never seen them affected by a fungal disease otherwise.

I will increase the ventilation this weekend, allow the plants to dry out and isolate the affected plant for some TLC.

On one of the affected leaves a black spot appeared in the center and has softened the tissue while not killing the trap. The area then began to grow, darkening as it spread. THe center rotted and the remaining leaf then blackens and dies. The spot can appear almost anywhere on the leaf but follows the same pattern. I have seen it affect the whitish base but not proven fatal to the plant.

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Black spot is fungal. It has motile spores supposedly. It thrives in humid and moist conditions. It spreads circumferentially within the leaf. It can cause triangular shaped spots too, which appear to have a vascular distribution. It can kill the plant when it gets right down to the actual growing point and allowed to fester.

A poor form of treatment (which I use) is to clip off all the infected appearing tissue, then wash very thoroughly in tap water, repot into new pot and new substrate mix, and semi quarantine from rest of collection.

The only way to know if this was successful is that first, the plant recovers, and second, the next bout of rainy, dreary moist weather does not reactivate the dormant disease.

Black spot is somewhat different from typical leaf blackening. It is most often apparent well before a trap on the leaf has even matured, so young leaves will have it. Black spot can and will attack any part of the inflorescence too.

Cut off the black parts. If the infection gets low down and out of control unpot and cut off the black parts.

Black spot and aphids are tops on my list of worst VFT pests.

Good luck,

Brad

Ventura California

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Black rot vs Black spot

My above post is regarding Black Spot, which I believe is a fungal disease.

Black Rot is due to any number of conditions which affect the VFT roots, from heat to toxins, including lack of root zone oxygen, and even transplant shock.

Black rot or Black spot seems like it’s a good time to repot.

Brad

Ventura California

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Hi Brad,

Thanks for your comments. Looking at past threads, it does seem a common problem.

Some questions:

Would a fungicide help to kill the spores?

What symptoms occur with black rot?

Vash,

No, that is not black spot. I will try and take a few photo's tomorrow so people can see what it looks like.

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Vash,

Your VFT lesions look somewhat similar, but not quite what I believe is Black Spot. Yours do look like some type of infection. But Black Spot is charcoal black, yours appears to be dark brown. Also Black Spot, if I remember correctly, has central retraction of the lesion, yours seem to be smooth shallow ulcers. Also I believe Black Spot involves the full thickness of the leaf, I cannot tell if yours are full thickness in the photos. When Black Spot gets going it attacks the younger leaves. As these infected traps develop you will see the black spots on the mature traps, but it does not usually attack the mature traps. It is apparent before the trap is mature, then the trap matures with the lesion already present.

“What symptoms occur with black rot? “

Black Rot is caused by specific fungal or bacterial infections, which results in typical Black Spots, so I call it Black Spot Disease. I use the term of Black Rot for the typical death of a shocked rotting VFT.

Black Spot is charcoal black. (see end note if you care)

Black Spot has retraction in the lesion, often central retraction.

Black Spot involves full leaf thickness.

Black Spot can have appearance of vascular distribution lesion (triangular shape).

Black Spot lesions begin on newly forming leaves and inflorescences.

Black Spot at least initially start as small less than 1mm black spots that slowly enlarge to 5mm or so very slowly.

Black Spot lesions remain small size until they coalesce and attack overwhelmingly at the growth point.

“Would a fungicide help to kill the spores?”

A fungicide should be helpful in fighting this disease, if it is caused by a fungus. I am not sure if it kills the spores or just kills the fungus itself. The disease could be caused by a bacteria however, then the fungicide would be useless.

Brad

Ventura California

End note: The Black Spot lesions seem to eventually form a brownish center, maybe this is spore formation. The brownish area occurs in the area of retraction. Otherwise the Black Spot lesions are charcoal black.

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Hugo, I don't know if you have access to it, but NEEM is supposed to take care of Black Spot in VFTs. I had it as well and the NEEM seemed to have taken care of it. I read somewhere that black spot occurs on apple trees and rose bushes and I have both of them within 300 feet of my plants. Don't know if that is where it came from but just wanted to give my experience. Hope it helps!

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Hi guys,

I don't think my VFT had a case of black spot or other infections.

My problem was having changing conditions for roots. Initially the media was only 3 inches of peat + perlite. Then 2 inches of perlite. So as Brad suggested..it was toxicity with water that is left over in the perlite layer.

This is the same VFT : the B52. its growing traps like crazy now:

THIS WAS WHEN I just repotted: about 2 months ago:

img2240dq4.jpg

By vraev at 2007-05-02

20 days ago:

554283496_09e7743338_o.jpg

THIS WAS 10 days ago:

743967621_fd40d660ba.jpg

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yeah! I find it really robust. Infact maybe faster than any other cultivar like the typical or dentate or red dragon.

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