Viruses

[nhbeek]

It's certainly not ecenomical for a retailer to test every plant.

It has become more common for high end sellers to test each plant and guarantee it arriving free of virus. There are several sellers on ebay who do this, and that was probably the context from which op's question arose. For them it makes ecenomic sense as their plants often sell for 200-1000$.

One's opinion of this practice is likely based on ones's opinion on the merits of maintaining a virus free (or as close as possible) collection. I value this because my plants are expensive and grown under lights, which results in them being in close physical proximity. If I had thousands of cheap cattleyas in shade houses I wouldn't care.