WASHINGTON — The preliminary national average price received by farmers for all wheat in May was $6.02 per bu, up 28c from $5.74 in April but down $2.85 from the May 2008 average of $8.87, the U.S. Department of Agriculture said in its latest

The national average price received for winter wheat in May was $5.58 a bu, up 32c from $5.26 in April but down $2.59 from $8.17 in May 2008.

The average price paid for durum was $8.34 a bu, up $1.06 from $7.28 in April but down $5.16 from $13.50 in May 2008.

The price of spring wheat other than durum averaged $6.78 a bu in May, up 30c from $6.48 in April but down $3.92 from $10.70 in May 2008.

The average price received for rough rice was $15.20 a cwt, down 10c from $15.30 in April and down 70c from $15.90 in May 2008.

The preliminary index of prices received for food grains was 206 compared with the 1990-92 base of 100, up 2.5% from the April index of 201 but down 27% from the May 2008 index of 283.

The May index for feed grains was 177, up 5.4% from a revised 168 last month but down 22% from 228 in May 2008. The average price paid to farmers for corn in May was $4.08 per bu, up 23c from $3.85 in April but down $1.19 from $5.27 in May 2008. Farmers received an average of $6.14 a cwt for grain sorghum in May, up 57c from $5.57 in April but down $3.18 from $9.32 in May 2008. The average price paid for oats in May was $2.16 a bu, down 21c from $2.37 in April and down $1.47 from $3.63 in May 2008.

The U.S.D.A. index of May prices received for oil-bearing crops was 193, up 10% from a revised 175 in April but 11% lower than 217 in May 2008. The national average price paid to farmers for soybeans was $10.80 a bu, up $1.01 from $9.79 in April but down $1.30 from $12.10 in May 2008.

The April index for dairy products was 90, down 1.1% from a revised 91 in April and down 36% from 140 in May 2008. The average price paid for manufacturing grade milk in May was $11.20 per cwt, down 20c from $11.40 in April and down $7.70 from $18.90 in May 2008.

The egg and poultry index was 142, up 0.7% from a revised 141 in April but down 4.7% from 149 in May 2008. The average price paid to farmers for all eggs was 61c per dozen, down 31c from 92c in April and down 26c from 87c in May 2008.