WASHINGTON (Reuters) - Americans buying food for their Fourth of July cookout will be paying more, the nation’s largest farm group said on Wednesday, with prices up 8.5 percent from this time last year.

An informal survey conducted by the American Farm Bureau Federation in May showed much of the increase occurred during the second quarter, when the cost of 16 grocery items -- including apples, pork chops and oat cereal -- was $46.67, up about 3.5 percent, or $1.64, from the first quarter.

“Prices of many food items continue to creep upward,” Jim Sartwelle, a Farm Bureau economist, said.

“Those increases, however, pale in comparison to the huge increases in energy costs -- for fuel, natural gas, and electricity -- that American families have become accustomed to over the past two or three years,” he added.

Food prices rose for 14 of the 16 items, with much of the increase fueled by tight supplies of grains and oilseeds worldwide.

Cooking oil and bacon showed the largest retail price increases, with a 32-oz. bottle of corn oil up 47 cents at $3.48 and one pound of bacon increasing 22 cents to $3.57.

The only items that posted a decrease were a dozen large eggs, down 34 cents at $1.82, and a pound of cheddar cheese, which declined 11 cents to $4.60.

The Farm Bureau, which represents livestock and crop producers, said farmers received just under $8.90 of the total $46.67 cost of the basket of products. That was a decline from the first quarter, when farmers got about $10 of the $45 basket.

A total of 87 volunteer shoppers in 36 states participated in the latest survey.

Higher feed and energy costs are driving up beef and poultry prices at grocery stores across the country, the U.S. Agriculture Department said last month.

Food prices will rise by 5 percent this year, according to USDA, marking the sharpest increase since 1990.