Heavy rain across northern China this month delayed the corn harvest, submerged fields in water and raised concerns about the quality of the crop in the world's second-largest producer.
China is expected to harvest one of its largest corn crops in years this season after tight supply last year pushed prices to record levels.
But rare heavy rainfall last week hit swathes of northern China just as the harvest was due to start, hampering gathering of the crop and drying of the grain.
"Generally speaking it will still be a bumper harvest, but the rain affects the harvest pace and the quality. With too much rain, farmers can't dry freshly harvested corn and it will cause high toxin levels," said Rosa Wang, analyst at Shanghai JC Intelligence.
Adding to the worries, a severe coal shortage has forced China to curb power supplies to industry recently, and may hinder the scope for large scale industrial crop drying in coming weeks.
Continuous rain has submerged crops across Shandong, Hebei and Shanxi provinces, as well as farther south in Henan and in Liaoning in the northeast.
In Qihe county in Shandong, the corn harvest would normally be completed by now, but has not started because of severe waterlogging in the fields, said Paul Niven, a China-based dairy consultant.
"The roots are rotting in the ground, and the stalks are dry and unusable for silage," he said in a social media post.