Matt,

Maybe I can help out here. From what I understand 99% of all Dats and Brugs are infected with what is commonly called "Potyvirus" which is I believe another name for Columbian Datura Virus. It is generally benign and shows no symptoms until the particular plant is stressed. Probably (my opinion only) what everyone is refering to as the "virus gene" is really just a propensity for brugs and dats to succumb to this virus. In most cases they aren't really affected at all. Years ago I was selling unrooted cuttings to a gentleman who had hooked himself up with a broker to resell rooted plants. His competiton informed the broker that his plants were infected with a virus - that's all the broker had to hear "VIRUS" that ended the deal. Supposedly the competetions plants were virus free because his plants all came from tip cuttings which the virus hadn't infected yet. "BS" (again my opinion). From what I know - viruses are in the plants cells and when the cells divide the virus will also be in the newly formed cell.(again my opinion).

Jack

blicon1, we are ignoring the guy behind the curtain as no matter what is stated it's not good enough and all his apologies don't cut it. I just don't have time for the games or anyone that insults folks.

Jack I'm a bit dubious too about the tip-cuttings notion, though it does seem to be the case that CDV symptoms generally only start to appear in about the fourth expanded leaf back from the shoot tip in many Brugmansia. Of course that does not mean that there are no viruses present higher up.

In Sect. Sphaerocarpium, B. arborea appears (just based on my obs here) to be either resistant (meaning it doesn't get infected) or totally tolerant (meaning it succumbs but is always symptomless), while B. sanguinea, and I imagine B. vulcanicola, seem to have little or no tolerance in cultivation - but perhaps they do in the wild. It was Monika G who pointed this out, and perhaps it suggests that there is something missing in the way we grow sanguineas and vulcanicolas that causes them to succumb so easily, rather than some inherent weakness. I keep a few sangs around in the nursery as a sort of coal-miner's canary to detect if CDV has come in!

In Sect. Brugmansia, most seem to have high tolerance and as you say there is little effect on the plants - usually. There are three clones of apparently pure B. aurea here - all very similar suggesting they are genetically related ('Chloe', 'Golden Butter' and one unnamed), which have little or no tolerance - they have symptoms year round and instead of the weak rash usually seen, the leaves are badly blotched and the plant vigor clearly diminished. Other aureas (and some suaveolens and versicolors) are highly tolerant and symptomless year round. Some cvs only get symptoms at low temps, but the temp at which it is triggered varies and some more sensitive cvs develop symptoms earlier in autumn and have them persist later into spring, than others. During the warmer months there are no symptoms at all.

I think its very possible that there are symptomless carriers all over the place. CDV was discovered on Brugmansias in the Sibundoy Valley in the 1960's. This is also the original home of B. 'Culebra', and it seems most improbable that that cultivar, for example, should have escaped infection! It is symptomless here year round.

Wow! Great info, Alistair! Well, I've yet to have a confirmed virus pop up at my place (though I have a couple in quarantine) & I have 'Culebra', so I guess time will tell. I think that there's still alot to learn about these viruses...

Good info and good explaination! Thanks! The cold weather symptoms vs the warmer weather pack of symptoms is something I have observed first-hand.

Karma, I was not apologizing to you. I have no reason to apologize to you. You spread misinformation. I simply asked you to stop. That is the end of it. I was apologizing to John and everyone else for taking it off topic. That is why I started this thread.

Alistair, I absolutely agree with your statement about Arborea.

As far as Vulcs. and Sangs. are concerned, if the virus does have something to do with the way we are cultivating them, I think the problems could be a lack of direct sun at some point during the day, a lack of well aerated soil, and people not balancing their fertilizer/soil to be more acidic. Preferably around 6.5 .

The regions Vulc. and Sangs grow in the wild have all of the above mentioned qualities. It also rains every day. Hence I shower my plants every day.

One thing I am curious about is whether symptomless but exposed plants can transmit virus - at all? at a lower level than plants with symptoms? equally?

Matt I'm sure its worth a try to make those adjustments. I also wondered if there isn't some micronutrient in those soils that might be necessary to allow an immune response (I have no idea what - just a wild thought!).

I have tried spraying some infected, symptomatic plants with aspirin (which is supposed to trigger an immune response (got this tip from LariAnn (sorry forgotten her surname - expert on Alocasia)). It did seem to bring about some improvement, but I didn't follow up with trying different frequencies and concentrations of spraying. The other biochemical that might work is methyl jasmonate.

Asprin and plant immunity reminds me of something I read awhile ago. Here you go.
~Lenette

Here is a link that might be useful: asprin and immunity

Very interesting: thanks Lenette!

Wow! That's great info, Alistair & Lenette! Here's a link to a product a friend recommended to me. This is more of a preventative measure along slightly different lines. This also relates to alot of the herbal fertilizers used in biodynamics.
Also, willow water is a homemade rooting solution from willow twigs. I wonder if it contains enough aspirin to be useful in this way?

Here is a link that might be useful: protection

I saw the thing about using aspirin on a garden show the other day. They said if pretty much any plant is looking sickly to crush an aspirin and add it to the water and water with it. Haven't tried it yet. Nice to see you Jack. Good information on here and might explain why my already stressed sang died right after I moved my daydreams that I suspect may have a virus near her. At the time I thought it was just getting too much sun. Within a few days the sang turned yellow and green and then died.

I am convinced that there needs to be a certain amount of trace elements in the soil. Iron, Sulfur, Calcium, etc. Also, after doing some research, there should be a good amount of silica in your soil. I use a silica solution every time I fertilize.

Food or should I say fertilizer for thought.

Also after doing some research I have decided that a soil PH of closer to 5.6 is better for vulcanicola.

Just my opinion though. Don't go killing your plants by listening to me.

what's silica solution Matt?

http://www.dyna-gro.com/003.htm

Doh!! ..... the stuff John provided a link to earlier!

Thanks Tom. Have to see it we can get it or something like it down here...