Maybe this could open a viable industry in Puerto Rico agriculture
Congress has the power under Art. 1, Sec. 8 to regulate trade among the states, just as it has the power to regulate foreign trade. As such, it is within the power of Congress to place such a tariff on foreign agriculture, and include PR agriculture. However, there is absolutely no reason why the Congress would do so, and every reason in the world why they would not. There seems to be a strong desire within Congress to see Puerto Rico right her economy, and saddling it with these tariffs would be counter-productive.
Just as domestic ag subsidies (and the converse foreign ag tariffs) make domestic agriculture relatively less-expensive, they both wind up distorting the market, increasing the cost to consumers or taxpayers, while advantaging the agricultural sector. So in the short term, this would advantage PR agriculture, though shielding it from competition removes the market incentives to be efficient. And when these protectionist measures are eventually removed, the protected sector suffers.
These same kinds of market distortions happened to Puerto Rico in the 1950s, when there were significant tax incentives to establish industry and manufacturing on the island. Those subsidies created a market distortion, and as the subsidies were removed in 2006, the economy contracted (and continues to do so today).
http://www.reuters.com/investigates/spe … ium=Social