Why does this worry you? Do you suspect you have an mv? For all I know most or even all of our common cannabis gene pool isn't even susceptible for it...
A bit more research shows that sunn hemp is not as close to hemp and our mj cannabis as the name suggests:
http://en.wikipedia.org/wiki/Crotalaria_juncea It is in fact a different family: Fabaceae
The wiki page that says what I posted above: "
Effects[edit]
The hemp mosaic virus infects plants of the Cannabis genus. The virus causes cellular mutations, stunted growth, damages plants
photosynthesis ability, and more. Cellular mutations usually manifest as discoloration and misshapen leaves. Discoloration usually manifests as yellow or grey mottling that can form a spotted, mosaic, or streak pattern. Misshapen leaves can be the result of damage to the plants at a cellular level, making them appear contorted and/or twisted. The stunted growth can cause a tremendous amount of crop loss due to lower than normal yields. Loses of 25% of flower production or more have been widely observed and reported.
"
has zero citations and could just be flat out an error...
A not-so-thorough search shows all sources that link SHMV to cannabis, besides that wikipage and Ed Rosenthal's book, are mj grow sites... Is Ed the source of the myth...
The other wiki page:
http://en.wikipedia.org/wiki/List_of_hemp_diseases is despite it's name not talking about SHMV in the context of our type of hemp (cannabis sativa) either.
Was that about ChemD? It was suspected that strain had it, several have tested their clones (apparently there's a kit to do so yourself) and it tested negative.
While it seems plausible that one of the many different mosaic viruses "could" infect cannabis... I have yet to find a confirmed case and at this point it seems highly unlikely there even is one.