Having read all the posts to date on the yahoo group as to virus and phytos and all.
Let's bring the discussion of healthy plants here to this board.
Tonny, you wisely suggested that we need to be growing strong healthy plants and you made mention of a weak plant in the vicinity to catch and display the virus so we could know. In the case of the viruses that Brugmansia are susceptible to, what would be the plant to have nearby that would catch and display outward signs of the virus? I'm concerned that I might someday down the road send something to someone else, and if I caught a virus, I would stop trading. I wouldn't stop growing my brugs, but would only import into my home, not sending them any further. Which plant or plants would be best to have around for this purpose?
weak plant as test to virus
Sanguineas are very susceptible to viruses. Check the stalks of the plants when they get larger for strange brown spots. LBJ had viruses in their sanguineas because a friend of mine replenished their collection with virus free ones. Also check leaves for weird mottly bumps. I had some sanguinea that had that, I think it was a virus so left them outside then destroyed them. Be very careful bringing in motley looking ones to the greenhouse. Best to isolate or destroy. I think the sanguinea I had that had a virus, the seeds came from T & H.
When I wrote to bring a weak plant in I was talking of a virus-free weak plant :) My point was, a healthy plant with a virus infection not necesarrly display any visible symptoms, but if you have healthy looking infected plants, the weak plant will also be infectet and then show conspicously signs of infection. In absense of other means, it will be a usable barometer for the brugs health in the garden.
Another thing I discussed was the possibillity to use vaccination of healthy brugs to make them imune towards certain strains of viruses.
Currently used methods used to make infected brugs virus free are thermo-therapy and cell tissue-culture.
It is working allright as long as the clean brugs grows in an sterile environment in our nurseries, but what happen, when the clean brugs enter our gardens?
It don`t has to happen - and it happen rarely - that a clean brug is brought into the garden and get infected.
That is why, professional people are working their butts of to ban seed/plant exchanges between "hobby growers". The argument is, that the average grower can`t spot a virus and possible unknowingly will trade his infected plants with other. Here I discussed the possibility of using plant vaccine.
A vaccinated brug is resistant towards virus, so when a vaccinated brug is traded for instance between you and me there will be no harm done. There are some economically weaknesses in the suggestion - i know - but I only discuss possibilities and don`t make the laws or finance their effectuations :)
Loss of entire crops is a part of the imagery in the discussion con or pro APHIS. I don`t try to de-dramatize that this actually happen. It does! But here there is a crucial difference between the reaction to an infection between healthy crops and weak crops. The tendency is, that weak crops are damaged severly by virus, whereas a naturally strong and healthy crop show no symptoms that can damage growth or yield. At this point I suggestet, that we prefer the healthy crops over the weak. Still, it won`t solve the virus problem, but it will reduce damages in crops. If I could, I would promise yòu all, that we could root our all virus strains in the world, but when I make a promise I will sleep better, when I know that my promises will be kept. So I chose to sleep better using common sense and my personal exsperience, - and you exsperience.
Thanks.
Tonny: Another question for you. I have a sanguinea which leaves looked sort of mottled in the summer, it's isolated out side. The leaves look fine now, maybe it was just the warmer weather which did that. What do you think? I was worried about virus, but I think it was just hot weather. Not super hot about 22-25 C.
I think, that you acted right by isolating the sang :) It could be anything, but I can see, that you live in zone 8b, so it is properly the heat. As I mentioned in another thread, nutrition deficit can also cause these symptoms. My few sangs are growing in light sandy soil and sometimes appear to be virus striken, but the leaves are yellow mottled due to deficit of calium and magnesia and maybe iron : If you like to mail me a cutting with leaves on I will try to determine, what it is, that is, if the brug-police is not coming after us *lol* I have an extra garden far away from the garden I produce plants and seeds in, where I grow plants, that I am not sure of :) So I like to examine it :) Are the leaves thinner, than usual, when they get the mottles? Did you find any spots or holes in the calyxes or cracks in the stems? Are the flowers malformed or just smaller, than usual?
Yea, I keep asking all kind of things *lol*
Let me know, what you think, brugcrazy :)
Here is more info about plant viruses.
http://www.disknet.com/indiana_biolab/v030.htm
There is an indicator plant for TSWV/INSV in the green house. I will look up the specific species. It's a bean.
and even more here.
http://www.im.ac.cn/vide/hostlist.htm
Thanks Calalily for the info of the indicator plant.
Tonny
I had looked at that one too, couldn't decide which one to use. I'm glad you added it.
I have some picts of a Datura inoxia specimen infected with virus.
The symptoms are yellow, mottled leaves and waguely leaf curl. The plant is normal of growth. The flowers and fruits grows normal too. Only the leaves show the symptoms.
I received it from an Swedish seed company in a mixed seed package labeled D. innoxia "Grandiflora". I have grown it our in three seasons now in my other garden and it shows, that the infection spreads with the seeds.
I will try and make a journal of it :) What more can I say, ... ?
Oh, yea, even when the plant is in terrific health and vigour, it show all the signs of being infected.