Vietnam's state-run Agribank will provide soft loans for coffee replanting until 2020 as part of a drive to replace old trees to boost output in the world's largest producer of the robusta bean.

Farmers in the five-province Central Highlands coffee belt could take up to VND150 million (US$6,900) per hectare for a maximum eight years to replace old low-yielding trees, the State Bank of Vietnam said in a statement.

The loan could carry a maximum interest rate of 7 percent per annum, compared with a range of 9.0-10.0 percent charged by banks for medium- and long-term dong loans now.

Old trees, or those in production for at least 20 years, account for more than 30 percent of Vietnam's total coffee area, the Vietnam Coffee and Cocoa Association said.

Output hit a record of 1.68 million tonnes (28 million bags) in the 2013/2014 season.