Charoen Laothammatas, president of the association, said the government and the central bank should implement urgent action to prevent the baht from becoming overly strong, reports the Bangkok Post.
The currency must be adjusted to a more competitive level while ensuring stability and minimising volatility, he said.
"Without prompt measures, a strong and fluctuating baht will harm the global competitiveness of Thai rice and farmers’ income," said Mr Charoen.
This year the baht has strengthened by more than 7% against the US dollar, while the currencies of other major rice-exporting nations such as India, Vietnam and Pakistan have depreciated. This has led to a significant exchange rate difference of more than 10 percentage points between Thailand and its rivals in the market, he said.
Mr Charoen said if exporters from Thailand, India, Vietnam and Pakistan all sell 5% white rice at the same price of US$350 per tonne, the income in local currency would vary significantly.
Competitors would earn between B1,000-1,250 more per tonne than Thai traders.
This disparity means Thai farmers receive less than their overseas peers, not because Thai rice is cheaper, but rather because of unfavourable exchange rates.
As export orders decline with higher rice prices, he said the impact directly affects farmers, particularly as the main harvest season approaches.
If foreign demand continues to fall, it could lead to a substantial drop in domestic rice prices.
Mr Charoen said the baht recently appreciated by 2% in a single day, making exporters reluctant to sell, while buyers turn to competitors to benefit from more favourable exchange rates.
"We want baht stability," he said.
"Exporters typically wait one to three months before payments are made. If we sell rice today at an exchange rate of B31 per dollar, and the baht appreciates to 30 per dollar in three months, we will suffer losses."
In addition, Mr Charoen said there are concerns over India’s plan to release about 20 tonnes of rice into the market, which would add pressure to it.
According to the Department of Foreign Trade, Thailand exported 4.30 million tonnes of rice in the first seven months of 2025, a 25.1% decrease year-on-year.
The export value totalled B86.4 billion (about $2.59bn), a 35.4% year-on-year decline.
The export dip was attributed to increased global rice production, particularly from India, which has resumed exports and is projected to produce more than 150mn tonnes.
Meanwhile, demand for rice imports from major buyers such as Indonesia and the Philippines has decreased. Baht volatility and appreciation have added pressure to exports, said the department.