A 17% tariff on most fresh tomato imports from Mexico to the United States was expected to take effect on Monday, July 14.

The Trump administration announced on Monday a duty of about 17% on fresh tomatoes from Mexico, which account for two-thirds of the tomatoes eaten in the U.S., and the end of an export deal between the two countries.

The U.S. just ended a decades-old tomato trade agreement with Mexico, and while prices could soon spike at grocery stores and restaurants across the country, one Stanislaus County farmer says not so fast.

Over the past 30 years, Florida tomato growers’ share of the U.S. tomato market has shrunk from 80% to 20%, as Mexico-grown tomatoes become more common on shelves, Arizona State University professor Tim Richards said. Richards predicts the price of tomatoes will increase by about 8.5%, half the amount of the 17% tariff.

A 17% import tax has been slapped on most fresh Mexican tomatoes. Proponents of the tariffs say it’ll help rebuild the shrinking tomato industry in the United States, but experts say prices will go up as much as 10% at the store in the meantime.