More than 98% of the areas were grown in the Mekong Delta, a year-on-year decrease of 11.6%, according to the Ministry of Agriculture and Rural Development.
Last year, the region saw a 0.4% fall in areas of the Autumn-Winter rice crops due to floods but each hectare yielded 180kg higher year-on-year to 5,220kg of rice. It brought the total output up to 4.02 million tonnes of rice, an increase of 3.2%.
The northern also experienced a significant decline in areas of the Winter crops, particularly those do not require much water like peanut and soya, due to lengthy heavy rains triggered by typhoons Pakhar and Mawar in late August and early September that have affected farmers sowing.
The areas of maize, sweet potato and soya fell by 15.6%, 34% and 29.8%, respectively, over the same period last year.
The ministry warned that the extreme weather may cause outbreaks of disease in the current Winter-Spring rice crops.