(Bloomberg) -- Coffee farmers in Vietnam, the world’s biggest grower of the robusta variety, collected about 40% of the 2022-23 crop as of early December amid concerns about bean quality due to prolonged rains, according to Nguyen Nam Hai, head of the nation’s coffee association.

Extensive rains hit major coffee-producing provinces of Dak Lak, Gia Lai and Kon Tum this month while farmers’ bean-drying capacity is still limited, Hai said during a meeting attended by agriculture ministry officials, coffee producers and traders on Saturday. Output is seen dropping 10% from an estimated 1.8 million tons in the 2021-22 season as growers in some regions cut investments while product costs increased, the Hanoi-based Vietnam Coffee Cocoa Association said in a report released during the meeting.

Yields and production are lower in farms that also grow profitable crops such as durians and peppers because growers pay less attention to coffee plants, according to the report.

Vietnam grows coffee in 20 provinces on over 710,000 hectares, up 67,370 hectares from 2015, with production area representing more than 90%, according to the report, which cited 2021 data from the agriculture ministry. The nation garnered a record high $3.9 billion from exporting 1.68 million tons of coffee of all types in the 2021-22 season, with robusta beans making up 89% of total shipments, Hai said.

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