[WG.]

I don't want whatever I harvest to have extracted more metal from the soil than it would otherwise

Open a command window and enter

tracert molybdenumUptake.com[/list]    

Seriously though, I got a few Soil Science lectures as part of a Chemistry course at Uni & I barely understood any of them.  Chemistry of the soil is  far removed from laboratory conditions.  Add to that complexity the physiology of the plant kingdom and you have yourself a very very large topic.  So I opted for the empirical approach ... try different stuff and observe the results - or in the words of another 'werks fer me'.  

[mushroom]

yeah, I know. I'm being devils advocate to some extent. it won't stop me spraying asprin solution on my peppers next year

[Rob the rake]

My toms and peppers got the treatment when they were watered. Be careful with the sprayer, as others have seen adverse effects on sprayed plants. Spraying seems to work for powdery mildew on cucurbits though.
The general concensus seems to be that it works well for fungal diseases.

As for plants other than the Solanaceae and Cucurbits, it's going to be suck it and see. I'll be trying it on my alliums for rust and white rot, early in the season as a preventative.

Rob.

[WG.]

T*sco only allows you to buy 2 packets of aspirin at a time.  Wonder how it'll go down when you have dozens of packets ... "Honestly, Mr Supervisor, the aspirin is for me cucurbits ..."  

[Rob the rake]

I'll watch out for the Sweeney raiding me plot!

Rob.

[sweet nasturtium]

I'm going to add a pack of aspirin to my weekly shop.  
Or should I use solluble aspirin? :?:

[potatopotato]

Brilliant tip, thanks Rob. I'm growing tomatoes for the first time next year and I'll be dosing the little babies up with aspirin in Spring!

[Rob the rake]

Go for it, PP!  Just bear in mind that it's easy to overdo it.

Rob.