China's average per-mu yield of wheat increased by 5.7 percent to 371.7 kilograms this year, an increase of 19.9 kilograms on last year, sources with the National Development and Reform Commission said on Wednesday. (1 hectare = 15 mu)

A survey by the economic planning agency showed China's major wheat-producing regions involved 2,045 rural families in 216 counties and cities in the nine provinces of Hebei, Shanxi, Shandong, Henan, Jiangsu, Anhui, Hubei, Sichuan and Shaanxi.

In the provinces of Hebei, Henan and Anhui, the per mu yield hit a record 390 kilograms. However, in the provinces of Sichuan, Shanxi and Shaanxi, the yield rose by more than 10 percent, according to the sample survey.

The average price of 50 kilograms of wheat in major producing areas has increased by 0.5 percent year-on-year to 72 yuan (US$9.4), it said.

China's grain output has risen for four straight years since 2004. Summer crops make up around 20 percent of annual grain output, which jumped 2.8 percent year-on-year to 497.46 milliom tons last year.

Total output of wheat that was sown last winter and reaped this summer is not yet available. Total yield of wheat that was reaped last summer is estimated at 98.68 million tons.