Wichita ? Kansas regulators on Wednesday lifted an embargo on wheat from 20 fields and three grain elevators in seven south-central Kansas counties after test results showed no detectable traces of a toxic fungicide applied too close to harvest.

But a separate later embargo remained in place on wheat from 11 northern-Kansas counties – including Jefferson – pending test results from those fields, said Lisa Taylor, spokeswoman for the Kansas Department of Agriculture.

Regulators had been especially concerned about south-central Kansas, where harvest has begun. On Tuesday afternoon, they embargoed some fields in seven south-central counties even before the test results were back. They were concerned about preventing potentially toxic wheat from those fields from reaching elevators and possibly contaminating the rest of the state’s winter wheat crop.

Test results are expected Thursday on samples from 11 northern-Kansas counties where farmers also improperly sprayed with the fungicide Quilt, which requires a 45-day waiting period between application and harvest.

Wheat prices surged Wednesday, a day after the news broke that Kansas had embargoed some winter wheat and more rain hit the flood-ravaged Midwest. Wheat for September delivery shot up 32 cents to $9.20 on the Chicago Board of Trade.

Test results are now pending on 51 fields encompassing 5,475 acres improperly sprayed in Decatur, Ellis, Gove, Jefferson, Logan, Phillips, Rawlins, Sheridan, Sherman, Thomas and Trego counties. A separate embargo for those fields was issued Tuesday night.

Adrian Polansky, Kansas secretary of agriculture, said Wednesday that regulators expected to find similar results from those samples.

“Protecting the integrity of the Kansas wheat crop and the reputation of our state as a provider of wheat to the world is of utmost importance,” Dusti Fritz, chief executive officer for the industry group Kansas Wheat, said in a statement. “We feel confident that a limited number of wheat fields in northwest Kansas, also under investigation, will yield the same good results.”

Meanwhile, the south-central Kansas farmers whose fields initially caused the wheat scare tried to get on with harvesting unaffected fields as best they could Wednesday.