I've never heard of Botrytis on spuds. Then, as usual, you don't know as much as you think you do, nor as much you like to tell everyone else you do. Look it up; gray mold (or grey mold, if you prefer...) affects potatoes. I may be confusing what sometimes affects my spuds with what sometimes affects my toms (especially in cool, damp years), but it doesn't really matter. As you say, as I already said, there isn't any way of getting rid of it, only of managing it.

My spuds grow healthily, from spuds that have usually been stored for anything up to 6 months. Your comments about aphids, blah, etc, may or may not be true, but they don't match my experience in the slightest. I only get cropping problems when, for reasons of weather, time, ill health (which usually means bad back!), I don't / can't give the garden the time it needs.

I'll admit to having regularly practiced one false economy - out-of-date seeds! ;-) They do last longer than the "sow-by" dates on packets would have you believe; in most cases, I've found that 2-3 years beyond are still productive, but 5, 6, 7+ is pushing it! ;-) In other respects, I tend to give more veg away to neighbours than I ever have a shortage problem.

Remember, Steve, I'm not trying to lecture people, to say "do this". All I'm saying is "I've done this & it's worked for me". Your way is to say "Huh! Rubbish!! I know better, don't do that, it won't work!!!" It doesn't hurt to try, and if it isn't successful, then do something else. Other folks can make their own minds up. But they won't try something new if it never occurs to them that they could. I prefer my approach to yours.

All gardening is somewhat experimental. No gardener ever stops learning. Unless they stop experimenting, anyway... ;)

Incidentally, every banana you buy (if you do) in a s/mkt is a Cavendish clone. So what?