Vietnam’s January-July agriculture exports to China fell 8.9 percent year-on-year to $4.7 billion, according to the Ministry of Agriculture and Rural Development's latest data.

Accounting for 20.7 percent of agriculture exports, China became the second largest export market during this period, behind the U.S.

Exports to the U.S. in the same period rose 12.6 percent to $4.8 billion, making up 20.8 percent of total agriculture exports.

Experts say the reason for the change is that China, which for years has been Vietnam’s largest buyer, has begun tightening its import policy this year, only accepting products that meet higher quality standards.

Another reason for the decline in exports is a weaker yuan to the dollar. China has let the yuan slide about 4.5 percent this year to the greenback as its trade war with the U.S. continued.

The depreciation has reduced imports from Vietnam as Vietnamese goods become more expensive to Chinese buyers.

Last year agriculture exports rose 9.6 percent over 2017 to more than $40 billion. The top five export categories with value over $3 billion each were shrimp, fruits and vegetables, cashew, coffee and wood.