Weakness in prices is making it harder for companies to keep investing in new ethanol plants, São Martinho Chief Financial Officer Felipe Vicchiato told investors Friday. The company makes ethanol from sugar cane and recently started up a new corn plant, but the executive said plans for expanding into corn are no longer economical.

“The bill just doesn’t add up,” Vicchiato said. He added that corn ethanol production will still grow by about 2.5 billion liters in the coming years as some of the recently announced investments start to ramp up.

The pessimistic outlook is a big shift for Brazil, a country that saw an explosion of corn ethanol plants recently take over an industry that was traditionally dominated by sugar cane. That has hurt financial results of cane mills, which then shifted to produce increasingly more sugar.

Read More: The Global Sugar Shortage Is About to Ease Thanks to a Corn Boom

Profitability of corn ethanol mills is also being hurt by lower prices of DDGS, a byproduct of corn ethanol used in animal feed. Recent declines in soymeal costs helped push down the price of such products, Vicchiato added.