Biofuel supporters greeted President Donald Trump with a standing ovation last week during his visit to the Southwest Iowa Renewable Energy (SIRE) ethanol plant in Council Bluffs to celebrate the removal of summertime restrictions on sales of E15 ethanol fuel blends.

“We lifted the restrictions on E15 just in time to fuel America’s summer vacations,” the president told the cheering crowd. “By unlocking the power of American agriculture and American energy, we are fueling our roaring economy.”

Permitting year-round sales of E15 will open the door to more opportunities for ethanol, farmers and rural communities, said Kevin Ross, a sixth-generation southwest Iowa farmer who joined Trump on stage after they toured the 110-million-gallon-per-year...