HONOLULU — For decades, tourists to Hawaii have brought home gift boxes of the islands’ famous chocolate-covered macadamia nuts for friends and family, but these days many of the kernels in the package might not be Hawaii-grown.

This little-known fact is surfacing at the state Legislature as lawmakers wrestle over legislation that would force macadamia-nut processors of iconic brands like Mauna Loa to disclose whether their products contain nuts from outside the islands.

Growers want the measure to protect their crops and farms, while commercial nut brands say what Hawaii needs is more capacity to process the nuts locally.

It’s the latest tussle over labels for agricultural products from a specific geographic area, a topic familiar to Hawaii due to long-running disputes over Kona coffee. It echoes similar challenges faced by maple syrup producers in Vermont.

The stakes are high for Hawaii’s 600-plus macadamia nut farmers, many of whom have small operations. Combined, they produced $62.7 million in nuts in 2021, just ahead of coffee in value and second only to seed farms that research genetically engineered corn.

Growers say they can’t find buyers for their kernel, and unharvested nuts are falling from their trees. Some farmers are giving up and trying to sell their equipment.

State lawmakers are due to vote on legislation Wednesday that would require consumer packages to disclose when they contain macadamia nuts grown outside of Hawaii. The bill would take effect Jan. 1, 2026, if it becomes law. Gov. Josh Green has not indicated whether he will sign it.

Macadamia nut trees are native to Australia and were introduced to Hawaii in 1881 by a Scotsman who managed a Big Island sugar mill. The first major attempt at commercial planting dates to 1948. Chocolate-covered macadamia nuts took off the following decade. In the 1970s and ’80s, Hawaii harvested more than 10 times the amount of the next four major producers combined.

But today, Australia, China, Kenya and South Africa all grow more than Hawaii. In 2022, the state’s production plummeted 29% from the year before.

Hawaiian Host Group sells macadamia nuts under some of the state’s most venerable brands. Their rectangular boxes of Hawaiian Host chocolate-covered macadamia nuts are favorites of tourists and locals alike.

CEO Ed Schultz told lawmakers his company buys one-third of the mac nuts grown in Hawaii. It has been doing so at a 35% premium to Australian prices in 2023, he said.

He said what the industry needs is more processing capacity.

Hawaiian Host wants the industry to form a co-op to run a new processing facility on the Big Island. But many growers are reluctant to join such a project without a labeling requirement that will differentiate their nuts from others around the world.