• Philip


A synthetic crystalline compound, lysergic acid diethylamide, (LSD) a powerful hallucinogenic drug or another recreational activity?

Peter Jackson’s documentary epic is an “addictive” look at who the Beatles were during the year of 1964 whereas the song "Lucy in the Sky with Diamonds" was not released until 1967. Shortly after its release the BBC banned the song for what they believed to be a drug reference in just one line. However, until the end of his life, Lennon maintained that the song was actually inspired by a painting that his three-year-old son Julian had made of Lucy O'Donnell, his classmate at Heath House nursery school.

So now we have all that cleared up maybe we should concentrate on something more important, the other meaning for LSD, Least Significant Difference.

When we look at trials results one thing, we should consider is the LSD since this is very important when drawing conclusions from the results.

If we have a trial with an untreated yield of 10 t/ha; Fungicide One producing 10.4 t/ha and Fungicide 2 providing 10.8 t/ha with an LSD of 0.5 (which actually means 0.5 t/ha because here we consider yield.) We can truthfully say that we are 95% sure that product B has increased yield significantly versus the untreated (the difference is more than 0.5 t/ha) and that this result would be repeatable in another trial or on farm.

However, scientifically, since Fungicide 1 increased the yield by 0.4 (less than the LSD of 0.5) in the real world, the difference in yield between the untreated and Fungicide 1 could be random chance due to natural circumstances and so if the trial was repeated, the yield results could be reversed due to chance, nothing to do with Fungicide 1 or how much you spent. Therefore, if the difference is less than the LSD, no actual yield benefit can be assumed or scientifically claimed; money spent can just as easily be lost.

This may not of course mean that “a painting cannot be made by a three-year-old son (or daughter)” representing these trial figures and then be present to you for approval! Much, I guess, as John Lennon’s son Julian did whilst thinking about Lucy O’Donnell in 1967.