It is the country’s largest wholesale produce market — described as “Costco on steroids” —and the nerve center for New York City’s food supply, providing more than half the fruits and vegetables that end up in takeout boxes and on restaurant plates and supermarket shelves.

But a strike over a $1-per-hour pay raise demand at the Hunts Point Produce Market in the Bronx, the first in over three decades, has dented its operations, leaving some produce to rot and threatening to snarl a normally seamless supply chain.

The last strike, in 1986, led to shortages of everything from artichokes to grapes.

This time, workers, members of a powerful Teamsters local, entered the sixth day of their strike on Friday after negotiations over a three-year contract broke down over pay. The union has asked for an increase of $1.60 per hour in each year of a three-year contract, with $1 of the raise to go toward wages. The market’s management, a cooperative made up of 29 vendors, countered with an offer of 92 cents an hour each year, with 32 cents of the increase going to pay.

The dispute raises questions about how employees are treated at a time when the pandemic has set off a stark divide between people who have had to keep showing up to work and others who have been able to work from home.

The workers, who earn between $15 and $22 an hour, say they deserve a better raise because they are risking their health to supply the city with food during the outbreak.

Six workers have died and about 300 have gotten sick after contracting the coronavirus, said Charles Machadio, the vice president of the union, Teamsters Local 202, and a veteran worker at the market. Still, the market has remained open around the clock, seven days a week.

“We’re all living in an uncertain world. I might be dead tomorrow, you might too,” he said. Mr. Machadio said that the market’s merchants should recognize that workers “have been coming to work, keeping your businesses going, risking their lives.”

A dollar raise, he said, would be a way of saying “thank you guys for coming to work, you really are heroes.”

None of the merchants contacted would speak about the labor disagreement, but they provided a joint statement.

It said the cooperative had spent $3 million on personal protective equipment for workers and shifted work flows and work stations to make the market safer, without having to lay off anyone.

“Despite all of these challenges, we are very proud to have kept our union workers — the vast majority of whom live right here in the Bronx — working and on payroll with full health benefits as the Bronx has seen an unemployment rate of 40 percent,” the statement said.

Though hundreds of workers have walked off the job, the strike so far does not seem to have had a significant impact on the food supply, according to some grocery stores supplied by the market.

Union members have set up picket lines outside the sprawling market every day, and on Tuesday the police arrested six of them for obstructing traffic.

Several prominent politicians, all Democrats, have waded into the dispute. Representative Ritchie Torres and Andrew Yang, who is running for mayor, rallied in front of the market terminal on Monday. And on Wednesday, Representative Alexandria Ocasio-Cortez distributed hand warmers and coffee to strikers.

“There’s a lot of things upside down right now in our economy,” she said. “One of those things that are upside down is the fact that a person who is helping get the food to your table cannot feed their own kid.”

The strike comes as labor groups have pushed the city to grant greater protections to workers, particularly those in the food industry. Last month, the City Council approved two union-backed bills that ban major fast-food companies from firing employees without a valid reason and allow them to appeal terminations through arbitration.

But at Hunts Point, the cooperative has pushed back, saying that the pandemic, which has closed many restaurants permanently, had dealt a blow to their business, costing it tens of millions of dollars in lost revenue.

Merchants at the cooperative purchase goods from farms and importers and then distribute products across the city and the broader region. The market moves 300,000 pounds of fruit and vegetables every day — about 60 percent of all the city’s produce by some estimates — and says it makes about $2.3 billion in revenues every year.

Despite the strike, the market remains open, and the cooperative has hired temporary strike-breaking workers to load and unload trucks, prompting angry outbursts from strikers whenever a truck arrives at the market’s entrance.

Noah Lea, who manages a branch of the CTown supermarket chain on the Upper East Side of Manhattan, said he gets all his green vegetables from Hunts Point, hauling in 400 pounds five times a week.

“I’m not worried right now,” he said, adding that the chain hedges against possible disruptions by relying on various markets, including the Philadelphia Wholesale Produce Market, a competitor to Hunts Point.

Other grocery chains, including Gristedes, have also looked to other markets beside Hunts Point since the last strike to avoid potential shortages and to get lower prices. Large chains, like Whole Foods and Trader Joe’s, do not depend on the market for their produce.

The striking workers at Hunts Point said that despite the safety measures adopted by the cooperative, the market is still filled with employees working at times in close quarters. The market is “so crowded, like Penn Station,” said one worker, Francisco Soto.

About 3,000 employees, 1,400 of them union members, work at the vast 113-acre produce market, Mr. Machadio said, which, along with separate meat and fish markets, makes up the Hunts Point Distribution Center.

“We’ve been exposing ourselves to get sick and get our families sick, but we haven’t slowed down one bit,” said Diego Rutishauser, 49, who has worked various jobs at the produce market for 27 years.

Mr. Rutishauser wakes up at 2 a.m. everyday and takes two buses and a train from his home in Jamaica, Queens, to make it to work at 5 a.m.

“We’re not asking the impossible,” he said.

Charles Platkin, the director of the New York City Food Policy Center, said the longer the strike continued the greater the likelihood that supplying produce would become more difficult.

But he said the workers deserved some acknowledgment for keeping the market functioning during a major public health crisis.

“Because it accounts for so much of our food supply, it’s important to recognize the power of that market and how important those frontline workers are,’’ Mr. Platkin said, “and how important it is for your city to pay attention to the labor force there.”