The price of diesel hit a new record Friday in the United States, as disruption from the US war with Iran squeezes voters.
The cost is now $5.85 a gallon, up from $3.71 a year ago, the AAA motorists' association said.
Diesel is used by farmers to run equipment, and it also powers the trucks needed to bring food to grocery stores.
US farmers faced a double whammy of surging fertiliser and diesel prices as the spring planting season got underway.
The Independent Grocers Alliance estimates that fuel-related costs can account for 15 to 30 percent of the total cost for some food products.
