I'm putting it in organics as that's sometimes the most confusing field in terms of working out what is going on with your plants. Please move it (and slap me) if it should be somewhere else!
This is Mulder's Chart, aka the Stimulation-Antagonism Chart.
http://www.apal.com....ONS July 08.pdf
edit: this information can also be found at the extremely useful (unless you're more vision impaired than you realise, like me) Charts Graphs and Other Useful Diagrams thread, to be found at;
It shows how levels of one available mineral nutrient impacts on the availability (or otherwise) of another.
It looks a little hairbrained at first, but makes sense fast enough when used in conjunction with the more commonly found "pH and Nutrient Availability" charts I'm sure everyone has seen before. Taught me a lot when I was studying.
Mulder's Chart is very handy to have around for those puzzling symptoms and for diagnosing multiple deficiencies brought about by overfeeding or local soil deficiency.
Remember that it depicts how the presence of increased levels of one nutrient causes less or more of another nutrient to be available to the plant.
To use for "working backwards" to determine which set of combined deficiency symptoms is actually the result of a deficiency of ONE nutrient, first work out which set of combination deficiencies is present, then see what other nute they all have in common, then think of "pushing your finger down" on the point of that nutrient .... it will "drag down" the availability of those it stimulates.
And it'd make a very confusing t-shirt design as well!
Edited by unrefined.hybrid, 31 July 2009 - 08:47 AM.