President Donald Trump’s threats to close the southern border are proving to be a windfall for Mexican avocado producers.

The price of Hass avocados from Michoacan, the heartland of Mexican production, jumped 34 percent on Tuesday, the biggest gain in a decade. Prices, which probably spiked as importers boosted purchases ahead of potential border issues, could double or triple if Trump makes good on his threat, said Roland Fumasi, an analyst at Rabobank. The Mexican Hass price was unchanged today.

Mexico is the biggest supplier of the fruit, accounting for 75 percent to 80 percent of U.S. consumption, according to data from the Haas Avocado Board.

A heatwave last year in California delayed the harvest, making the U.S. even more reliant on Mexican supplies. “Because California is late and it’s a small crop, Mexico is accounting for nearly all of our avocados,” Fumasi said.

Avocados crossing from Mexico into Texas were fetching more than $60 per 25 pound-carton, up from about $42 a week ago and $38 a year ago, according to U.S. Department of Agriculture data.

“This is already the highest price we have at this time of year,” said David Magana, a vice president and senior analyst at Rabobank.

Avocados feature on almost half of U.S. menus, according to Chicago-based researcher Datassential. Once mainly confined to dips and salads, the fruit is now seen as a super-food thanks to its nutritional characteristics. The dark green-colored, bumpy-skinned Hass variety is preferred in guacamole and avocado toast for its rich, creamy flesh.