PLAINVIEW – Jesus Madrigal stared at a field of grapes across the street from his house in this dusty Central Valley town, as a chemical odor drifted toward him.

“They’re too close,” he said of the grapevines.

Madrigal said there were no grapes in Plainview when he moved here from Mexico two decades ago to settle in the unincorporated town of 1,000 in Tulare County. But now the grapes have moved in next door, along with the pesticides that farmers spray to kill pests that could damage the fruit.

Tulare County’s fields, nestled close to heavily Latino cities and towns, are now at the center of a battle over the future of the pesticide chlorpyrifos (pronounced clor-PEER-if-oss). The chemical can induce tremors and dizziness in adults and developmental delays in children who were exposed while in their mothers’ wombs, according to multiple scientific studies.

In 2015, the last year for which statistics are available, California’s growers applied more chlorpyrifos than farmers in any other state — mainly in the Central Valley, according to the U.S. Geological Survey and California’s pesticide usage database. Farmers use it to protect crops such as almonds and oranges from ants, stink bugs and other insects.

In October 2015, the U.S. Environmental Protection Agency proposed banning all agricultural uses of chlorpyrifos. The agency had until the end of March to decide whether to outlaw the chemical based on feedback from the public and follow-up studies. On March 29, Scott Pruitt, the head of the EPA, rejected the proposal, saying that there wasn’t enough scientific evidence to deprive farmers of a needed tool or to justify EPA scientists’ follow-up studies.