CHICAGO • Missouri has issued its first fines over the misuse of a farm chemical in 2016 that went on to be linked in different formulations to widespread U.S. crop damage this year, the state said on Thursday.

Authorities fined eight people a total of $145,125 for improperly spraying the chemical known as dicamba, used to kill weeds, in what Missouri called "the first wave of civil penalties issued to applicators," according to a statement.

The delay between sprayings last year and the state's action shows how a long process of investigating many complaints about dicamba use is straining resources in farm states.

The United States has faced an agricultural crisis this year caused by the new formulations of dicamba-based herbicides, which farmers and weed experts say have harmed crops that cannot resist the chemical because it evaporates and drifts away from where it is applied.

Monsanto and BASF say the herbicides are safe when used properly.

Last year, farmers sprayed dicamba illegally in states including Missouri, Tennessee and Arkansas on soybeans that Monsanto Co. engineered to resist new versions of the chemical, according to regulators and weed scientists.