Quote:
Originally Posted by SouthPark
Can definitely see your side of things there! Although, maybe just depends on circumstances, conditions, and a grower's own choice and/or view ------ as well as on the grower ----- eg. new grower, commercial grower, etc.
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Of course growers have a choice, a choice that I might disagree with, but I'm not them. Personally, I see viruses as a man-made (i.e. man is the primary vector) problem that has the possibility to back-spread into nature and destroy native populations (this according to a scientific researcher). I also see it as a preventable problem that became very expensive due to negligence over a long time. That no man is an island, and while they might not care that they have viruses, there is always the possibility that those viruses escape (e.g. with visitors touching plants, orchid shows, insects if outside etc.). I personally believe I should leave a hobby better than before I came in.
Now, I am no moral authority, nor are my standards necessarily the objective standards by which everything is judged. But in
my garden, whether a plant remains healthy is immaterial; if it has a virus, it goes in the trash, period. And if one day, I have a cultivar that wins 14 FCC/AOS awards, and the source plant gets virused, then I will destroy that so as not to let its inferior genetics pollute the gene pool. Because as long as there are healthy plants with genetic variation, the genes exist to recreate any phenotypic expression with enough trials.
But I guess this philosophy is sort of unwarranted since I was just trying to give Nlamr some basic reasons on why he might want to test, and how he could test without testing every single plant.
Quote:
Originally Posted by MJG
In terms of statistical testing, a simple random test in this example would not be sufficient. You'd need a stratified design plan (ie identifying and testing differing segments of the overall population, not just random samples from the whole). Each stratum once identified would have its own calculated sample size, blah blah blah. It gets complicated. A random test of the entire population without using strata becomes a broad brush when you have pockets of orchids raised and grown differently. You can end up with an overall false sense of confidence or otherwise skewed results with a simple random test.
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I was making the assumption that every orchid has equal probability, and that there are no interaction effects (but to that end, we could randomly choose orchids from different grexes and test a grex further if an orchid test positive). You're right, of course, that it's not that simple, and that we would hire statisticians to be as rigorous as possible. I guess even if it is not rigorous (and highly flawed), the general process still makes sense since testing some plants give a high level picture over testing no plants. I guess instead of calling it statistical testing, I would prescribe testing some plants periodically over testing all plants at once.