Prices for Vietnam’s 5 percent broken price fell 1.47 percent to $335-345 a ton Thursday from $340-350 last week, Reuters reported.

The plunge has happened after China began applying stricter regulations on agriculture imports. Vietnamese traders say that Chinese importers are unable to buy rice from Vietnam because of new technical barriers China has erected.

The largest importer of Vietnamese agriculture produce has been increasingly tightening import regulations because Vietnamese exports to China have a history of problems, including counterfeit certificates, declarations and orders, the Ministry of Agriculture and Rural Development had said in a report last June.

Vietnamese goods has also been violating quality standards for agricultural products set by China, it said.

Vietnam’s Ministry and Industry and Trade recently said it would organize several trade promotion trips this year to boost rice exports.

Rice exports to China will likely face more challenges next year as its imports are forecast to decline by 2.94 percent from this year to 3.3 million tons because of abundant domestic supply, the U.S. Department of Agriculture said in a report earlier this month.

From January to July, agriculture exports to China fell by 10 percent year-on-year to $3.35 billion, according to Vietnam Customs.