I must admit that garlic viruses remain a mystery to me. At first I had to get used to the fact that they dry down before harvest, so naturally the leaves are yellowing one way or another. The ones that dry down a bit streaky I thought looked like virus pics, but as Henry said, all garlic has some latent viruses, it may or may not be that the pattern emerging as they dry is due to virus. One thing I have noticed is that there never seems to be any spread of virus-looking leaves from one type to another in the field here. Which is not what they say about it. The experts in France for example have made virus free varieties from meristem tissue culture, but it is also said that they rapidly acquire viruses in the field and that virus is spread by aphids. The aphids here show no interest in garlic at all, so maybe it is a special type of aphid we don't have around.
If all the garlic has some latent virus - or virus exposure in the field - then it must be that some varieties are more prone to symptoms while others are not. The porcelains and the glazed purple stripe that I have seen, are ones that don't show any of that streaky looking leaf. While all the standard purple stripe varieties I've seen are especially streaky, and the others somewhere in between. I think the late season types are maybe less well adapted to our climate, which may not be the case elsewhere. Anyway, all told, I haven't been able to clearly identify or understand anything about garlic virus at this point.
