Three plants in my collection are suddenly having their leaves turn brown?

[Sashoke]

I posted a week or so ago that my N. burkei had some sudden and unusual brown leaf on its new growth, I was worried it might be pests but the leaf simply died off and it grew normally since then. Well I thought little of it until today when I noticed three more of my plants have the burned and brown looking leaves...

However their growing conditions have not changed at all and they've otherwise been happy for 2 years here. The majority of my collection is also doing just fine and arent showing any of the same symptoms, even though theyre being grown in the same exact conditions as the other plants. Could anyone help me identify the problem here? My best guess is lack of humidity, that has always been a hard one for windowsill growing, but the humidity hasnt changed or gotten lower recently.. so I dont know. The next obvious answer is too much sun or heat but that isnt the case either, it never gets over 75F and they get only a couple of hours of direct sun every day, and then indirect sun for the rest of it. Just like theyve always gotten for the past 2 years where they've grown normally.

So Im worried it is pests, disease or fungus. What do you all think?

N. ventricosa x arist, distorted growing leaf, brown and black coloration. Rusted looking leaves.

N. robcantleyi x spathulata, very distorted leaf, never unfurled all the way. Distorted looking growing leaf. Burned leaves.

N. ventricosa "red" same symptoms, black distorted growing point, burned leaves.

And to further my confusion, I have tons of other plants right next to these that are not being effected at all and growing healthily.

All plants are being grown on the same southern facing windowsill, they all get about the same amount of sun every day. 2 or so hours of direct sunlight and then shady indirect light for the rest of the day. The humidity is low, hovers around 40 to 50%. Never goes higher than 60 and never lower than 30. Temperatures never get above 75F and are usually around 65-68 at night. I occasionally feed pitchers with osmocote flower and vegetable pellets. I water with nothing but distilled water and all plants are potted in the same 50/50 Perlite Sphagnum mix.


Thank you for any replies!

 

[Plant Heathen]

Two years? Have ever reported them?

 

[Sashoke]

Two years? Have ever reported them?

The N ventricosa "red" is 4-5 years old and has been repotted twice, the N. vent x arist is 3 or 4 years old and has been repotted once. The N. spath x rob is 3 or 4 years too and has never been repotted. Ive been looking to repot it but havent gotten around to it yet. Though I wasnt aware bad soil could cause leaf damage like this? In any case the soil in the other two pots look fine to me, no decomposition, no funny smells.

 

[Plant Heathen]

for me when a leaf starts turning brown/black at the tip it's a sign of not ternogh water. So in my thoughts if the soul is bad or the plant is root bound. The roots may be getting damaged and water isn't being consumed at a regular rate. I'm no Nep expert I'm just getting into them. Just going by basic plant care.

Just my thoughts and my 2 cents

 

[Sashoke]

for me when a leaf starts turning brown/black at the tip it's a sign of not ternogh water. So in my thoughts if the soul is bad or the plant is root bound. The roots may be getting damaged and water isn't being consumed at a regular rate. I'm no Nep expert I'm just getting into them. Just going by basic plant care.

Just my thoughts and my 2 cents

Well, they're most certainly not root bound, the pots they're in are very generous for Nepenthes. Ill get to repotting the spath x rob though, its moss is looking pretty decrepid.


Im wondering if this isnt thrips though? Seems to be all the symptoms, though I havent brought in any new plants and I cant see any thrips with a magnifying glass.

 

[Harow]

I'd say it's both humidity and nighttime temps.
They'll do better in at least 50% humidity all the time and temp drops to high 50s.

 

[Sashoke]

I seem to have caught a leaf right as its beginning to turn crispy.. looks like it starts out splotchy and rusted?

I dont know why the humidity would only just now be causing problems, all the plants here adapted to the lower humidity a long time ago and have done great ever since. Thankfully winter is coming shortly, and its dropping to 60F outside now so im going to be sleeping with my window open I think. It'll let the room cool down easier, see if that helps at all.


Alternatively, does anyone think this could be caused by too little light? The only plants experiencing this are higher up on the shelves where they get less light. Theyve vined so far up the window they're at the very tippy top where barely any sun gets to them. The lower leaves of the plants arent doing it (Where there is plenty of light) and the N. ventricosa red has a healthy basal growing.

 

[SFLguy]

Take a magnifying glass and look to see if you have any bugs like mites

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[Sashoke]

Take a magnifying glass and look to see if you have any bugs like mites

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I have and couldnt see anything, and I was using a fairly powerful loupe.

 

[Sashoke]

I think this might be a new growth point?

 

[elgecko]

Looks like it might be thrips.

I'd spray with rubbing alcohol once a week for a few weeks and maybe get a systemic pest spray.

 

[Applulz]

Yeah this is probably some kind of pest problem. I had the exact same symptoms a few months ago with my N. robcantleyi x spathulata and observed small white mites creeping around the plant sometimes.

I solved the problem by moving the impacted plant outdoors (I live near a nature reservation in Florida) and within a few weeks it started growing fine again; it even sprouted a basal shoot! I am assuming because whatever it was got eaten by the indigenous wildlife that now infest the plant instead. It is incredible how much stuff CPs will catch down here. I actually made the switch from growing sarrencia to nepenthes specifically because my sarrencia would always topple over from the sheer volume of prey and spew half digested bugs all over the place. Gross.







Here it is after being moved outdoors. It had the huge leaf jump right before the mites got to it, but is now looking like it is doing well.

 

[Sashoke]

Looks like it might be thrips.

I'd spray with rubbing alcohol once a week for a few weeks and maybe get a systemic pest spray.

Would rubbing alcohol actually be effective vs thrips? How heavily should I dillute it and how much should I spray on the plant? Do I let it dry off or wipe it off after ect..?




As far as systematics go, would orthene work? https://www.amazon.com/gp/product/B008ISRH02/ref=ox_sc_act_title_1?smid=A1L0J6J9ZYHA6P&psc=1

Ive never had pests before so im new to this issue.

 

[Sashoke]

Moved the shelf today these plants were growing on so I could get a better look at the underside of their leaves, and yep.. looks like thrips.

It also seems the ventricosas growth point has completely withered.. this is very unfortunate. If im lucky enough it might sprout a new one, otherwise looks like im relying on its basal

 

[elgecko]

To be honest, I'm not sure just rubbing alcohol will work on thrips, never tried it. I used it for aphids & scale.
Thrips I also use a systemic pest spray.... maybe next time I'll just try the rubbing alcohol. I don't like systemic pest sprays.

Use 70% rubbing alcohol. Anything higher the alcohol evaporates too fast and wont kill the pests. Spray plant completely.... you are done. Repeat weekly for a few weeks.

 

[Sashoke]

To be honest, I'm not sure just rubbing alcohol will work on thrips, never tried it. I used it for aphids & scale.
Thrips I also use a systemic pest spray.... maybe next time I'll just try the rubbing alcohol. I don't like systemic pest sprays.

Use 70% rubbing alcohol. Anything higher the alcohol evaporates too fast and wont kill the pests. Spray plant completely.... you are done. Repeat weekly for a few weeks.

Should I spray on the soil too? Ill probably try this to atleast slow them down until I can buy the systematic.

 

[Sashoke]

As I wait for Osmocote in the mail I guess ill keep updating this thread as the situation develops. Maybe it will ring a bell for someone who knows what it is more definitivley.

 

[Sashoke]

Well, I've treated with Orthene twice over the span of two weeks as directed and the problem is still persisting on my N. burkei, the other plants effected all lost growth points but have put out new growth points lower on their vines, excluding spath x rob, which isnt looking good. It is still unclear whether the plants that put out new growth points are cured or not, time will tell. N. burkei is still putting out sickly leaves that wont unfurl though. It has not lost its growth point, making it seem like it is the most resilient of the effected plants despite also not showing any progress in treatment.


I repotted all effected plants and their roots looked healthy as could be, no funny smells or black necrotic growth.


Any more ideas what it could be? Maybe some disease or viral infection?