Diesel prices are at their highest level ever.

Many U.S. farmers need fuel for their machines right now.

They use it for combines, tractors and other equipment.

They are gathering soybeans and corn.

These are two of the country's biggest crops.

This price jump makes a hard year even harder.

Farmers already pay more for fertilizer, seeds and equipment.

Diesel reached a record price in the U.S. on Sept. 4.

It averaged $5.85 a gallon for the first time.

The six-month war with Iran had stopped the world's fuel from moving normally.

By Friday, the average price was $6.05 a gallon, according to AAA.

Prices are now 60% higher than before the war.

The U.S. and Israel started the war in late February.

Back then, the average was about $3.76.

Paul Mitchell is a professor at the University of Wisconsin-Madison.

He said the prices hurt.

He said the cost affects more than harvesting.

It also affects moving grain and silage.

Farmers move these from fields to farms, and then to buyers.

Jason Kurtz is a corn and soybean farmer near Forest City, Missouri.

He said he paid twice as much for diesel this year.

His combine uses 200 gallons a day.

He expected to use it for 30 days.

Kurtz is 49.

He said he still had to run the machines and use the diesel.

So it cuts into his profit.

He said his money was already tight.

He had paid more for fertilizer and chemicals.

Kurtz voted for President Donald Trump.

He said he planned to delay some farm work.

He hoped diesel prices would fall.

Mitchell said farms with little money have the hardest time.

They struggle most to decide what to cut.