Estimates of organic produce and tree nut acreage continue to show increases, as they have since the federal government began compiling such statistics in 1997.

The U.S. Department of Agriculture’s Economic Research Service recently published updated estimates that show a 209% overall increase in certified organic acres of vegetables, fruits and tree nuts from 1997 through 2011.

Acreage of organic crops is estimated because the USDA does not track the statistics itself, instead relying on reports from state governments and third-party certifiers to provide data.

Vegetables accounted for 147,446 of certified organic acres in 2011, compared to 48,227 acres in 1997. That’s a 205% increase.

Increasing at a slightly faster rate — 213% — organic fruits and tree nuts accounted for 154,716 of certified acres in 2011, compared to 49,414 acres in 1997.

Organic fruits and vegetables continue to lead the organic food category, accounting for 43% of total organic sales in 2012, according to the October edition of the USDA publication “Amber Waves.”

According to the Economic Research Service (ERS) report, organic vegetables account for about 6% of all U.S. vegetable acreage. Organic fruits and nuts account for about 4% of the total U.S. acres for those commodities.

Fresh produce is still the top-selling organic category in retail sales, according to the ERS report.

The USDA reports about 4 million acres of U.S. cropland was used for fruits and nuts in 2012, with about 154,000 of those acres certified as organic. Total vegetable acres for 2012 were about 2.8 million, with about 160,000 acres certified organic, according to the agency.

Increasing organic acres for produce are not reserved for U.S. consumption — the Department of Commerce tracks the export of key organic commodities and shows two-thirds of those commodities had increases in export values from 2011 to 2012.

Organic U.S. apple exports led the trend, more than doubling in value from $46.2 million in 2011 to $99.8 million in 2012, according to the Commerce Department. Pears from U.S. organic growers also saw a significant year-over-year increase with $8.9 million in value logged in 2011 and $20.6 million logged in 2012.

Two U.S. organic fruits saw sharp declines in export values from 2011 to 2012. Grapes dropped from $60 million to $39.7 million and cherries dropped from $30.6 million to $6.4 million in export value, according to the Commerce Department statistics.