Although pecans are native to the American South, it could be that they might be even more productive somewhere else in the world. Maize, for example, grows amazingly well in Iowa, even though it's native to Mexico. But if pecans could be grown more productively elsewhere, it's unlikely we'll ever know. Experience tells us that American trade barriers would likely be erected to hobble any entrepreneurs who attempted to compete with domestic growers.
Much has been made of tree-nut growing in California during the current debate over the drought. Almonds have been especially targeted, but pistachios are an important crop as well, and while domestic almonds and other tree nuts certainly benefit from tariff policy — here's a tariff schedule for those who are interested — pistachio growers in the US have the added benefit of bellicose American foreign policy.
In a 2013 article at Mondoweiss, Yash Levine examined the effect of the US embargo against Iran on the pistachio industry, through the experience of one particularly wealthy farming couple, Lynda and Stewart Resnick:
For as long as anyone can remember, Iran had been the world’s main supplier of pistachios. But Carter’s 1979 embargo on the country effectively cut off Iranian pistachio growers from the American market and created a need for alternative pistachio production, which was virtually nonexistent in the United States.
Seeing a massive opportunity, the Resnicks began to snap up thousands of acres from Mobil Oil and Texaco in order to create pistachio and almond orchards. They steadily bought up more and more acreage all through the 1980s for rock-bottom prices because of a long period of drought. By the end of the decade, the Resnicks had amassed enough farmland to rival Oligarch Valley’s biggest and oldest billionaire farmer clans: 100,000 acres—nearly 160 square miles—growing cotton, pistachios, almonds, oranges, lemons and grapefruit.
They didn’t just grow the crops, but packaged, processed and distributed them as well. Economic sanctions against Iran were renewed and intensified under every single president after Carter, and all the while America’s domestic pistachio farming exploded. In the past thirty years it has grown from a couple of hobby farmers to an industry generating close to $1 billion...
Economic sanctions are what have allowed the Resnicks to create their pistachio empire, which would suffer a severe blow if relations with Iran were ever normalized. Iran’s pistachios are considered to be superior to America’s, so much so that Israelis still buy Iranian pistachios shipped in through Turkey. Surely the Resnicks would never be able to compete with Iran on the pistachio free market. And so the Resnicks did what any smart and ruthless American would do: they made common cause with oil companies, Islamophobes, neocons and Likudniks, and began funneling money to think tanks and political advocacy groups that take a hardline approach with Iran. Economic sanctions, sabotage, vilification—all these things worked in the Resnicks’ interest. Bombing some of Iran’s pistachio fields wouldn’t be so bad, either…