A dream I had last night made me wonder: imagine I had a magical acre of land, on which I could grow any crop. What crop has the greatest value per acre of harvested product? For the sake of our discussion, lets stick to legal crops, and restrict ourselves soley to the crop itself, not things made from it, to eliminate anomalies like the particular acre in France on which are grown the grapes for some hideously expensive wine. If we factor in the production cost, does the answer change?
The Tomato is the most valuable in the U.S and the second most valuable in the world (might lose to rice or wheat).
Will cite if possible.
Note: I am not a farmer, and as a city-dwelling youth, know nothing about it firsthand. From Eric Schlosser’s book Reefer Madness:
Strawberries. They’re a very risky high-profit specialized crop, and our consumption of them has increased dramatically- California leads the US in agriculture. In 1970, there were about 600 acres of strawberries in the Santa Maria Valley, now there are six times that amount. CA accounts for more than 80 pct of strawberries grown in the US and ~25 pct grown in the world. The cost of production can be anywhere between $12,000 - $30,000 an acre.
Great book, by the way. 
Saffron, IIRC. Worth far, far more than fruits or vegetables.
Now, is it a “crop”? I think it is.
In the U.S. it is tomato.
Unless you read this about tobacco:
http://fujipub.com/fot/working.html
And in case you care, cattle are considered crops, too.
I was also thinking of saffron. Since you specify that anything will grow on this magical acre, you might do some research and figure out the hypothetical yield of truffles or chantrelle mushrooms?
According to this page:
Saffron is, indeed, one of the most expensive crops to purchase per pound. But, an acre of land will only produce about 10 lbs of it. So the retail value of an acre of saffron plants is only about $3650, which is obviously eclipsed by strawberries at a production cost of $12-30k, as citrus x paradisi reports.
I haven’t researched it, but catfish and pine trees must fairly high in dollars per acre.
Vanilla.
Yield of ~4000 lbs per acre. (cite )
Price: ~$120/lb (cite)
Nets approximately $480,000 per acre, retail. Not bad at all.
Safforn is a crop, but the yield per acre is so low (8 to 10lbs/acre) that while the price is high (approx $100/lb to the grower) the end result is that it is not even close to being as valuable as strawberries. Strawberries can yield as high as 27,600 lbs/acre and sell for $1.00/lb wholesale to the grower. These numbers are what I could quickly find while skimming the web, but you get the idea.
I live in So Cal and there are still strawberry fields surrounded by suburban development. That has to tell you something right there. They paved over the asparagus fields to make shopping malls, but the strawberry fields remain.
Not the asparagus fields! Oh, how the children of California shall miss those verdant fields of green… 
It’s worth noting that strawberries, and tomatos too, I’d reckon, depend on the migrant labor available readily in the United States. Saffron pickers are probably trained for the job.
Thanks.
Isn’t some opium grown legally (for codeine et al)?
No idea what the $/acre is tho.
Brian
That Southern California is full of Beatles fans?
I would guess that it’s not terribly high. Generic codeine based cough syrups and narcotic analgesics are among the cheaper prescription drugs out there, at least IME.
Some crops have brief harvest times, and you have to add a time control.
This may be true, but a little bit of coca goes a long way. Also more importantly I would imagine the per acre grossing from these crops would be high compared to others discussed. However I have a feeling security overheads may cut a large chunk out of the profit margin.
Whoops i meant…opium of course… not coca… but theres another one.
Can you “grow a crop” of truffles? I thought their charm (read: expense) is due to the fact that they grow wild and have to be found.
Wouldn’t you need to first grow a forest on your magical land and THEN grow truffles? Can fungus grow alone?
Aren’t there some strawberry fields in a prime location near Disneyland?
My understanding is that a storm which hit Madagascar (the world leader in vanilla) recently wiped out a good deal of the vanilla crop, thus these numbers may be temporarily inflated.
I should think that marijuana would be up there; there are plenty of farmers in the Midwest and Tennessee, Kentucky who have made the switch from grain crops in order to hold on to the family farm…