A state agency set up to foster diversified farming on fallow former plantation agriculture lands has lost its longtime leader, James “Jimmy” Nakatani, who died Sunday.

Nakatani, a longtime watercress farmer who also once led the state Department of Agriculture over a career that stretched at least 45 years, died suddenly and unexpectedly, according to the agency. He was 74 years old. A cause of death was not stated.

The agency’s board of directors voted at an emergency meeting Monday to appoint Mark Takemoto, ADC’s senior executive assistant, as acting executive director.

Takemoto said in a statement that Nakatani’s life and passion were about promoting and cultivating local agriculture.

“His background and experience on the matter proved invaluable to ADC,” Takemoto said.

Nakatani was a graduate of Waipahu High School who earned a business administration degree from the University of Hawaii. His career in agriculture included becoming the third-­generation operator of his family’s Oahu watercress farm in 1978, serving as president of the Hawaii Farm Bureau and heading the state Department of Agriculture from 1995 to 2003.

ADC was established by the Legislature in 1994 partly to improve infrastructure of closed sugar and pineapple plantations for new diversified farming endeavors, but the agency has struggled over the decades to realize much of that vision and in recent years has clashed with lawmakers.

Nakatani was appointed to run ADC in 2012. In 2021 some lawmakers unsuccessfully attempted to abolish the agency after a scathing performance review by the state auditor.

Deficiencies cited in the audit included a lack of statutorily required market research, no meaningful agribusiness plan, informal tenant arrangements, state procurement rule violations, records in disarray and poor board oversight.

“After almost 30 years, we found that ADC has done little — if anything — to facilitate the development of agricultural enter­prises,” the audit said.

The state auditor also had been tasked by lawmakers to conduct a separate financial audit of ADC, but the auditor said that wasn’t possible because ADC hadn’t kept financial records since its inception.

Nakatani at the time acknowledged operational issues, which he said suffered from poor funding, but disagreed with a conclusion in the performance audit contending that ADC had done little to fill a void left by plantations.

“We talk about we want to move agriculture, but not much money is given to agriculture,” he said at the time.

Partly in response to the audit, leaders in the House of Representatives convened a special investigative committee in 2021 to examine ADC, though the proceeding largely shifted into a feud with state Auditor Les Kondo and not much attention was paid to committee findings on ADC.

In 2022 the Legislature severed ADC’s administrative attachment to the Department of Agriculture and put ADC under the state Department of Business, Economic Development and Tourism.

ADC owns irrigation ditch systems on Oahu and Kauai along with about 22,000 acres of farmland mainly on the same islands. Most recently, the agency, which had a staff of 14 in 2022, has been improving and leasing 1,200 acres of former pineapple plantation land in Central Oahu to diversified farmers.