BENGALURU: Rice export prices in Thailand dropped to their lowest level in four months this week, amid weakness in the domestic currency and sluggish demand, while Vietnamese rates rose after incessant rains sparked concerns about harvest in the country.

Thailand's benchmark 5% broken rice prices were quoted at $455-$485 on Thursday, their lowest since early-March and below last week's $514-$520.

"Demand has been flat in (the) recent weeks and this has driven prices down," a Bangkok-based rice trader said.

Exports prices also fell, despite the Thai baht weakening to a near one-month low against the US dollar this week, as the Thai variety was still expensive compared to competitors like Vietnam and India following a severe drought earlier in the year.

Heavy rains-led supply woes pushed rates for Vietnam's 5% broken rice to a three-week high of around $425-$457 per tonne from $415-$450 a week earlier.

"Persistent rain in the Mekong Delta continues to hamper the summer-autumn harvest, affecting rice supplies," a trader based in Ho Chi Minh City said.

In India, rates for 5% broken parboiled variety were quoted at $377-$382 per tonne this week, up from the last week's $373-$378 per tonne.

Buyers in Africa are increasing purchases to ensure they have ample supplies amid rising cases of the novel coronavirus in the continent, said an exporter based at Kakinada in the southern state of Andhra Pradesh.

Also helping prices, the Indian Rupee traded close to a more than three-month high against the US dollar.

Rice production in the top exporter is likely to surge to a record high due to good monsoon rains, and as the government raised the price at which it will buy the new-season crop.

Meanwhile, Bangladesh is likely to cut taxes on rice imports in an effort to rein in soaring domestic prices, the country's food minister Sadhan Chandra Majumdar said.