If Donald Trump’s threats to “build a wall and make Mexico pay for it” come true, they would cause a serious economic crisis in the U.S., including having as high as a twofold increase in prices of avocados and other fresh fruits and vegetables.

According to experts, the U.S. President’s initiative to impose a 20 percent percent import tariff on all Mexican products would not only cause a significant decrease in the availability of foods consumed in California and the rest of the U.S., but would also be a direct violation of the North American Free Trade Agreement (NAFTA) currently in effect between the United States, Canada, and Mexico.

“Since a big part of the Agreement was a prohibition of precisely these types of taxes or tariffs, if we were to perform an imaginary exercise of how things would be, it would be devastating for industry; in the U.S., we greatly depend on products exported from Mexico, specifically on about 60 percent  of the Mexican products brought into the United States,” said Everard Meade, Director of the University of San Diego’s Transborder Institute.

Avocados would be the first product to as much as double in price, say researchers. Because of the huge consumer demand in the U.S. for imports from Mexico and other countries, these actions would cause prices to go up quickly in California. Recent production numbers show that Mexican avocados are superior in quality and cheaper to grow than in Southern California, where there is less local production because it is not that viable for growers.

“It rained more than usual this year, but this is an atypical year, and although the drought is over, this coming year we are expecting a hot summer and then a drier winter. That means growers will have to pay much more for water, or for the State to have to give them water. Furthermore, they do not like the water they’re getting now because it is recycled and has a higher salinity, which keeps avocados from growing properly, which makes the leaves dark and affects the taste of the fruit,” shared UCSD Professor Oscar Romo.

At the end of the day, it is the consumers who have the last word as to the difference in size and taste between Mexican and Southern California avocados; however, fruit and vegetable sellers are already worried that these increases will then extend to other products such as tomatoes and strawberries – also imported from Mexico and in high demand in San Diego and the rest of the state.

Historians also fear potential price increases in other products which require Mexican imports. Before the existence of free-trade agreements and treaties with other countries, the red tape and the long time it took to bring these inputs into the U.S. made them more expensive, causing prices to be two-to-three times higher for the American consumer.