China’s national statistics bureau had said corn output in 2017 was 215.9 million tonnes but the new data showed last year’s crop was 20 percent larger at 259 million tonnes, the China National Grain and Oils Information Center (CNGOIC) said.
The statistics bureau could not be reached after office hours.
The report said that new data sharply increases the planted acreage for corn last year from 35.5 million hectares to 42.4 million hectares. Yield was also up slightly to 6.1 tonnes per hectare from 6.09 tonnes per hectare.
It is not clear why the data has been adjusted.
The crop in 2016 was revised up to 263 million tonnes, and 2015 data was changed to 265 million tonnes, the highest ever.
CNGOIC said it expects the 2018/19 crop to increase by 0.05 percent to 259 million tonnes.
The estimate is sharply higher than the agriculture ministry’s most recent forecast of 213 million tonnes.
The ministry is due to release its monthly forecast on supply and demand of key crops on Thursday. Last month it failed to publish the data, citing technical problems.
