I even have a theory that it can be carried by insects that suck the leaves on plants like spider mites, thrips and other bugs. Not even looked in years to see if there have been any real studies lately. Not like ole Uncle Sam spent much money on research until the tax payers starting lining their pockets.
It’s been real a long time, but it wasn’t until fairly recently that plants were tested and shown to carry it.
First carrier I ever saw it on was “Chems Sister” then again a couple of years later on a Dead Chemdog which was a cross of the original Chem to Deadhead OG. Last time I saw it was on the original real deal GG#4, and I saw 5 or 6 other people grow it just fine. I ran it in my test room and made it turn within weeks of the flip.
One thing about it when a plant has it you can smell it right off, and it always smells the same on every strain. There have been times I have said no way this plant looks perfect, but it has that smell and sure as shit your bummed.
Another sure tell sign is you’ll have perfect leaves everywhere, and then here and there you get these twisting tips. It’s why a lot of people think they have Broad mites because it does look sort of similar.