Farms turned into fire fuel.

For several decades this has been a burning issue in Hawaii as the demise of plantation agriculture has given rise to increasingly frequent and big wildfires on fallow farmland where grasses, haole koa and other easily burned vegetation supplanted sugar cane, pineapple and cattle ranching pastures.

So it was no surprise to local fire experts that the closure almost three years ago of what had long been the largest sugar cane plantation in the state would be followed by a giant, out-of-control blaze.

“It was just a matter of time,” said Clay Trauernicht, wildland fire specialist at the University of Hawaii College of Tropical Agriculture and Human Resources. “It was not if it was going to happen. It was when.”

Trauernicht said the amount of land in Hawaii that has caught fire annually quadrupled to 20,000 acres from about 5,000 acres over the last several decades, and that the main correlation during this time has been the shuttering of plantations.

“It’s pretty much the driver,” he said.

Sugar cane for more than a century was the biggest crop in Hawaii and drove the economy with more than 150 plantations. The last big wave of closures happened in the 1990s. Hawaiian Commercial & Sugar Co., covering 36,000 acres in Central Maui, was the last to close in December 2016.

The raging fire in Central Maui began Thursday, and by Friday had grown from an estimated 1,000 acres to around 10,000 acres covering some former HC&S lands.

Concerns that fallow former HC&S fields could feed a fire of historic magnitude were well placed and even a reason for practice.

In early 2017, four months after HC&S made its final harvest, which left cane in the fields, the Maui Fire Department conducted an exercise with more than 150 firefighters because HC&S would not be able to manage risks and fight fires the same way it had for so long in its fields, according to a Maui News report.

The Maui News story quoted Maui Assistant Fire Chief David Thyne, who expressed concern that his department “could potentially be dealing with incidents of a magnitude that we haven’t dealt with before.”

Maui County officials were not available Friday to comment on fire risk challenges pertaining to former plantation lands.

Historically, plantations used their own manpower, water sources and heavy equipment — especially giant bulldozers — to snuff out unplanned fires. In some cases they even helped county fire departments battle fires elsewhere.

Thyne, in the 2017 Maui News story, said 90% or more of the time, his department would respond to unplanned Central Maui cane field fires by calling HC&S.

Pacific Fire Exchange reported that 600 acres of the former Central Maui sugar cane fields burned in 2017.

HC&S owner Alexander & Baldwin Inc. pursued reusing its Maui plantation lands to grow diversified crops and raise cattle after quitting sugar cane. The local company was still in an early stage of that effort when it sold the plantation property for $262 million late last year to Mahi Pono LLC, a firm created by a California farm management company and a Canadian pension fund manager.

Shan Tsutsui, Mahi Pono’s senior vice president of operations, said in a statement Friday that 10 employees have been dedicated solely to helping fight the fire and have done work that includes using three tractors, two front-end loaders and one bulldozer to cut firebreaks.

Mahi Pono estimated that about 4,000 acres of its land had been burned by the fire.

The company said fields that have been burned included some that were being prepared for planting crops, some that were fallow with old cane and some containing grasses and small trees.

The nonprofit Hawaii Wildfire Management Organization said over 98% of Hawaii wildfires are caused by people and that most ignitions are accidental incidents along roadsides that include sparks from machinery, heat from car exhaust systems and other things.

Elizabeth Pickett, the organization’s executive director, said people need to be more aware and can be more careful but that wildfire fuels need to be managed better.

“Fire can only burn where there is fuel,” she said.

Big fires on former plantation lands have occurred throughout the state for decades. Just last month a fire on fallow agricultural lands above Waimea and Kekaha on Kauai scorched 2,100 acres — an area that had burned three times previously since 2012.

Pickett said a major challenge in reducing wildfire risks in Hawaii is insufficient funding for landowners and other organizations even though the percentage of land burned annually in the state, 0.5%, is equal to or more than any other state.

Federal grants are available, but Hawaii has difficulty competing with western mainland states where gigantic forest fires dominate national headlines and have been more threatening and destructive to life and residential property.

“That has huge repercussions on the fallow ag land,” she said. “People don’t realize we live in such a fire-prone state.”