If you want to talk about the rising price of commodity grains, you need to include peanuts. Consumers are being told to "Get your peanut butter — before prices soar." Kraft will raise prices for its Planters brand peanut butter by 40% starting October 31.

Brace yourselves, peanut butter lovers, prices are set to shoot up in the coming weeks following one of the poorest peanut harvest seasons growers have seen in years.

Prices for a ton of runner peanuts, commonly used to make peanut butter, hit nearly $1,200 this week, according to estimates by the U.S. Department of Agriculture. That's up from just $450 per ton at this time last year.

Shoppers should expect these price increases to spread their way.

Kraft will raise prices for its Planters brand peanut butter by 40% starting October 31, while ConAgra's Peter Pan brand will see prices jump between 22-24% this month, according to company spokesmen. A spokesperson for Unilever, which produces Skippy, would say only that the company "is watching the commodities market very closely and will take pricing adjustments as needed".

Representatives for J.M. Smucker, which produces Jif, did not respond to a request for comment.

What's to blame for this sticky situation? The intense heat and drought that hit the southern U.S. this year, said John Beasley, a professor of crop physiology and management at the University of Georgia.

"It was just unmerciful, and we had a lot of problems setting the crop," he said. "I literally walked some fields that had zero yield."

In addition, Beasley said, high prices last year for other crops, such as cotton, corn and soy beans, led farmers who might otherwise have grown peanuts to focus their efforts elsewhere.

Overall, U.S. peanut production will hit 3.63 billion pounds this year, down 13% from last year's total of 4.16 billion pounds, according to a Department of Agriculture report released this week.

Americans spend almost $800 million a year on peanut butter and consume more than six pounds of peanut products each year on average, according to The National Peanut Board, a farmer-funded research and promotion group.

Sales may not be so smooth during the looming price crunch. In any case, a shift in peanut butter consumption shouldn't make a huge difference to the nutritional quality of most Americans' diets, said Marion Nestle, a nutrition professor at New York University.

"For the average person in America," she said, "it would be a good idea to eat less of almost everything."