Apparent drosera blight - any ideas?

[sykosarah]

How do you introduce springtails without them all being eaten? I tried that today (realizing the reason why my Venus flytrap never had any fungus appear even though I didn't wash the medium was probably because of them) placing five or six of them in a pot, and an hour later they all got caught by the seedlings (which gives me an evil sort of pleasure but defeated the purpose of carefully setting them in the pot).

[jdallas]

Hi Carter,

The last time a saw symptoms like this on our plants is when we sprayed a tray of D. adelae with Gibberellic acid to try and boost growth. They turned white at new growth like that, then died. CP don't respond to it the way regular plants do since their nutrient uptake is so different. Have you been using any Gibberellic acid for seeds or any other purpose, or the powder in the vicinity of these plants?

Jeff

[sflynn]

I had something like this happen to a bunch of my D.capillaris's, the plants just slowly dwindled away. Never found out what it was, though it could of been mineral build up in the soil.
Did you try repotting one plant in fresh media to see if it helped?

[incidencematrix]

Hi, all. Just to leave a final (?) update for anyone reading this thread (or finding it later), the cause of the mysterious drosera blight has still not been established. The good news is that it has not spread further, and the impacted plants so far seem to have (with a few exceptions) begun the process of recovery. Since there was no reason here to suspect that any obvious intervention would do more good than harm, my only action (other than the usual supportive care) was to remove as much of the blighted tissue as possible in order to encourage the plants to grow new fronds. It is unclear whether this intervention had any effect, either, but it at least made it easier to track progress.

The final score card, for future reference is as follows:

- Water: Clearly not it. All plants had the same watered from the same source (ROI filtered water, tested to verify low TDS) before, during, and after the event.

- Soil: Also unlikely: blighted plants and healthy plants coexisted in the same medium before, during, and after the event. The medium was the usual (unremarkable) peat/sand mix in which I grow most bog plants, sans issue.

- Light: Nope. The blight was not related to lighting conditions (see the initial post about the non-clustering of affected plants).

- Parasites: The blight did not _damage_ the leaves in any visually apparent fashion (verified by inspection under a microscope), and no macroscopic parasites were in evidence. Insects and arachnids would seem to be safely ruled out. Fungal, bacterial, or other parasites in the root system are not easily ruled out, so these could have been present.

- Developmental issues: Although many of the blighted plants were from a single batch of capensis seeds, at least one plant of a different species showed the same symptoms (and most plants from the initial batch were healthy). Given that all plants were young, it is not impossible that this was simply an unlucky coincidence in which multiple plants (from more than one batch) hit an unusual "failure to thrive" milestone at the same time. This seems improbable, however.

- Toxins and such: The plants were not sprayed with anything, nor otherwise fertilized (save with their usual food source, bloodworms). However, just out of curiosity, I sprayed one pot of capensis containing impacted members with a dilute solution of MaxSea (which I use on some other CPs). This had no effect whatsoever. One possibility that cannot be ruled out is that there was some contamination in the container of bloodworms I was using, but this is very dubious - one would need to assume that only some of the batch were contaminated (because the rest has been used before and since with no ill effect), and that the contaminated portion was somehow not well-mixed with the rest of the container (also very, very unlikely).

- Temperature: There were no significant temperature fluctuations during the period (these are indoor plants in SoCal) and in any event this would not explain why only a few plants were impacted.

In trying to reconstruct the history of the blight, the only other thing I can add as that immediately prior to the blight the tray water levels were much higher than normal (on purpose, because I had to leave them for a few days). These plants are robust to that, so flooding per se wouldn't do it (nor only affect a few plants!). My best guess so far is that the relative flooding might have tweaked the local fungal/algal/bacterial ecology in some of the pots such that a few plants (more or less at random) experienced blooms of some root-dwelling pathogen (resulting in blighted growth for a period). This is not a great explanation either, because one would expect e.g., browning/drying of fronds in that case, and one would still imagine this to produce more within-pot autocorrelation than was observed (though root issues, and fungus in particular, can be very local). It seems marginally better than "aliens did it," and is more compatible with what was observed than the other known alternatives.

Should anyone else encounter this issue, my advice at this stage is to hold tight, try not to stress the plants, and perhaps remove impacted foliage (although whether this has more than a cosmetic effect is unclear). With the exception of fragile seedlings, the plants will probably recover, and I've seen no indication that the condition is prone to spreading after the initial outbreak.

If anything changes, I'll post further updates. Otherwise, thanks to all for your suggestions!

-Carter

[adelea]

Maybe that particular batch of peat had something extra in it, or possibly something attacking the plants chlorophylls or a gene responsible for colouration, a disease of some form perhaps, otherwise it looks like some kind of mineral poisoning, which could attack the plants chlorophylls and effect light absorbance.
Another possibility could be mites within the soil, they may not have attacked the other drosera you have yet as they might target already sick plants.

[Dave Evans]

Well, your plants are not blighted. The symptom resembles heat stress or a nutrient deficiency. You mention the water was a little high during this period. Could root stress resemble a nutrient deficiency???

I seen a similar problem on 'Bain's Rocket', but the affected rosettes died and regrew from the roots.


Oh! Could this be a virus that spreads to even the developing seed?