oscar169
Farming 🌱
Supporter
- 2,729
- 263
Yes in the Back of the book there is about 4-5 pages of Bibliography
Tobacco Mosaic Virus (TMV) Testing @ Home In Minutes
G
GeneticFreak
- 192
- 18
RNA PRO
Frostynugman
- 1,192
- 263
Ive just encountered this problem with WTF and Dubble D by cannarado. just killed 4 phenos that have the discoloration. Did infact see it spread when the plants were topped and were touching the affected leaves in close contact. I tried taking more leaves off but it made the plant spread it to others that didnt even start with ended up having it later.
Seamaiden
Living dead girl
- 23,596
- 638
IIRC, bugs like fungus gnats make great MV vectors.
Frostynugman
- 1,192
- 263
Bought a USB microscope because I thought I did have bugs and I in fact do not have any bugs at all. The leaves with the yellowing that were touching the topped plants made it vector through that. I have progress pictures and have been doing experiments with the 8 quarantined plants and also just introduced a brand new clone into the area. Topped it and made sure the leaf was touching and in 24 hours the leaves were yellowing
H
haole
- 102
- 28
Viral diseases in Cannabis are poorly characterized.
The Agdia immunostrips are good technology being antibody based, and are therefore accurate for the targeted virus, and sometimes, close relatives. However, virus diseases in plants are extremely diverse, and no single assay will identify them all. The term mosaic is nonspecific and only refers to a symptom, although many viruses include it in their name because the first host they were identified in had said response. Just for reference though Cucumber mosaic virus, Tobacco mosaic virus, and Cauliflower mosaic virus are unrelated. Plant virologists use numerous assays when they deal with tissue that has suspect infections, and it is not uncommon to run around 20 different antibody assays with tissue that has an unidentified virus, along with electron microscopy, mechanical transmission to other plants, and PCR.
New technology (Next=generation sequencing) can do that for much cheaper, but it takes a technician extensive time to look at the results, and close to $1000 for one sampling. Even then, some viruses are very sensitive and the chain-of-custody and timing of the sampling could have effects on the results. Think positively though; this would of cost 10,000,000 10 years ago.
It would be unusual for fungus gnats to serve as vectors, as they are in the order diptera, wherein few plant virus vectors exist. Instead look to the hemiptera: aphid/leafhopper/whitefly etc. Thrips and nematodes and even fungi are more likely viral vectors, but in most cases the relationship is specific. Many viruses are spread or are known to spread only via mechanical means: leaves rubbing together, scissors/dirty hands, etc.
The Agdia immunostrips are good technology being antibody based, and are therefore accurate for the targeted virus, and sometimes, close relatives. However, virus diseases in plants are extremely diverse, and no single assay will identify them all. The term mosaic is nonspecific and only refers to a symptom, although many viruses include it in their name because the first host they were identified in had said response. Just for reference though Cucumber mosaic virus, Tobacco mosaic virus, and Cauliflower mosaic virus are unrelated. Plant virologists use numerous assays when they deal with tissue that has suspect infections, and it is not uncommon to run around 20 different antibody assays with tissue that has an unidentified virus, along with electron microscopy, mechanical transmission to other plants, and PCR.
New technology (Next=generation sequencing) can do that for much cheaper, but it takes a technician extensive time to look at the results, and close to $1000 for one sampling. Even then, some viruses are very sensitive and the chain-of-custody and timing of the sampling could have effects on the results. Think positively though; this would of cost 10,000,000 10 years ago.
It would be unusual for fungus gnats to serve as vectors, as they are in the order diptera, wherein few plant virus vectors exist. Instead look to the hemiptera: aphid/leafhopper/whitefly etc. Thrips and nematodes and even fungi are more likely viral vectors, but in most cases the relationship is specific. Many viruses are spread or are known to spread only via mechanical means: leaves rubbing together, scissors/dirty hands, etc.
H
haole
- 102
- 28
To add a good quote to the above:
"
The following calculation
indicates the scale of our ignorance. Horváth (1983) tested
the host range of 24 viruses on 456 angiosperm species.
He found 1312 new host–virus combinations, that is, 12%
of those he tested. There may be about 250,000 species of
angiosperms (Heywood, 1978) and over 1000 plant viruses
have been recorded. If the 12% rate applied on average to
all these plants and viruses, then there may be more than
30 × 106 new compatible host–virus combinations awaiting
discovery. In relation to this figure, the number of
combinations already tested must be almost negligible."
From Plant Virology, 5th edition. Roger Hull, 2014.
"
The following calculation
indicates the scale of our ignorance. Horváth (1983) tested
the host range of 24 viruses on 456 angiosperm species.
He found 1312 new host–virus combinations, that is, 12%
of those he tested. There may be about 250,000 species of
angiosperms (Heywood, 1978) and over 1000 plant viruses
have been recorded. If the 12% rate applied on average to
all these plants and viruses, then there may be more than
30 × 106 new compatible host–virus combinations awaiting
discovery. In relation to this figure, the number of
combinations already tested must be almost negligible."
From Plant Virology, 5th edition. Roger Hull, 2014.
pugliese63
- 297
- 63
Those pics clearly indicate a broad mite infestation. I've been down that path and chased every disease and defeciency without any results. After a good treatment with Forbid everyone recovered.
I'm not an expert but in over 20 years of reading online forums I have yet to see one person whose plant tested positive for TMV.
I've mentioned before, Tom Hill and his crew obtained test kits and tested a lot of plants, all with negative results.
The Chemdog line does display some varigation, it shows up in my cuts of Ultimate Chem 2011. This has been mentioned numerous times.
I'm not dismissing the theory that TMV can infect cannabis I've just not seen it documented anywhere. I do see consistent misdiagnoses for it though, i.e. broad mite infestation.
Seamaiden
Living dead girl
- 23,596
- 638
That's why I don't use the term TMV, only mosaic, because we can only describe symptoms here. Learning that these symptoms also closely resemble something like broad mites is further greatly helpful. Or somethin' like that.
Great posts, gentlemen. Thank you.
Great posts, gentlemen. Thank you.
H
haole
- 102
- 28
Well, I am not an 'expert' in this arena, but I am knowledgeable and experienced in it.
While negative results for TMV in a TMV specific assay is good, it is almost negligible in the large scheme of things, due to the diversity of viruses, and other microorganisms such as phytoplasma and viroids. Tobamoviruses, the genus from which TMV originates, are common and severe pathogens of plants, but considering that they are only mechanically transmitted and not known to be vectored by an insect, it is in fact more likely with Cannabis that we would be dealing with a different viral disease unless in a nursery with multiple species.
Multiple tests have to be run when you are working with an unidentified disease. It is important to note that because unidentified viruses can be extremely elusive, it is common to test for all other possible casual organisms before testing for viruses.
Please remember people, at the end of the day we might not have YET seen devastating crop loss to a virus in Cannabis. Nonetheless, viruses change rapidly, and their virulence/pathogenicity/host effect can rapidly change as well (similar to how the flu is different every year.)
The practices that are associated with the growth of Cannabis, because there has been a sort of internal quarantine system while illegal, may have helped to control possible viral or other agent spread. However, now that legal gardens are mass cultivating it, it is not a matter of if a serious virus exists in our chosen plant, rather a matter of when. Luckily that legal nature will also finally allow true diagnostic studies of its associated plant pathogens as well...
Last edited:
M
Miami Mango
- 8
- 3
Indeed I myself ordered theAgdia strips and tested my plants with a negative result to any TMV or mosaic virus. I did get a microscope and did see those little bastards (Broad mites) never have I encountered such a destructive organism. Just as mentioned above FORBID by Bayer found on Amazon.com will get rid of those sons of bitches and any other bug for that matter. Even fungus nats. Just make sure its used at least 45 days prior to harvesting.
H
haole
- 102
- 28
Just to be clear, the agdia strips do not test for 'any mosaic viruses.' One strip tests for one virus, with some exceptions such as the two virus ORSV and CyMV strips, or the Potyvirus strips (which test for all 120 member species of the Potyvirus genus).
The TMV strips will only test for either TMV, or TMV and other closely related viruses. Most other 'mosaic viruses' are distantly or unrelated to TMV though.
The TMV strips will only test for either TMV, or TMV and other closely related viruses. Most other 'mosaic viruses' are distantly or unrelated to TMV though.
Latest posts
-
Who Are the Best Breeders in 2021?- Gmix posted
-
DBottom leaves turning yellow - please help :/
- defarmer83 posted
-
Dolomite Lime... 50 lbs... $6.25... Limited Time- LoveGrowingIt posted
