Marco Carmenatis prepares a box of limes imported from Colombia at Marco produce in Miami. Carmenatis said there have been no lime imports from Mexico recently as a tight supply has driven up the prices for the citrus. (Joe Raedle/Getty Images)

It’s been a tough spring for Cinco de Mayo fans and the bars that keep them plied with tart margaritas, as the Great Lime Shortage of 2014 has been threatening to break up the party.

Cocktail prices spiked, bars passed off lemons as substitutes, and a 40-pound carton of limes shot past $100 in the United States, four times the normal price.

Nearly all the limes thumbed into Corona bottles come from Mexico, amounting to a half million tons of U.S. imports. And there have been many theories about what caused the unusual prices, including that the cost of extortion by drug cartels in the lime-growing state of Michoacan was being passed on to customers north of the border.

But Mexican lime growers attribute the high prices to something more mundane: bad weather. Unusually heavy rains last winter led to an outbreak of a fungus that destroyed many lime trees and reduced the national supply.

“It’s climate change,” said Enrique Saavedra, director general of B&S Grupo Exportador, a lime supplier in Veracruz, the Mexican state sending the most limes to the United States. “People speculate that it had something to do with security in Michoacan, but it wasn’t that.”

In an effort to engage Latino voters ahead of a push on immigration policy, President Obama hosts a Cinco de Mayo fiesta at the White House. (AP)

Michoacan lime farmers agree. In that state, farmers grow mostly key limes, or what they call “limón mexicano,” which are smaller and contain more seeds than the variety normally sold in the United States. Mexican farmers refer to that second type as “Persian limes” (Lima persa). In Michoacan, for example, farmers grow about 110,000 acres of key limes and just 10,000 acres of Persian limes, said Sergio Ramírez Castañeda, president of a lime-growers organization in the state.

Ramírez said the “main reason” for the price hikes was the heavy rains that damaged the crop. The reports of violence or extortion affecting the price was “pure speculation.” He said that his organization had not received “a single report” of extortion or of any lime trucks being stopped by criminal gangs.

But that’s not necessarily unusual, as many people are afraid to report cartel abuses. In Michoacan, the violence and extortion by the Knights Templar drug cartel was the main reason that a citizen militia uprising has spread widely during the past year. The militiamen have taken control back from the cartel in much of the state, with lime farmers on the front lines.

The way Knights Templar extortion worked, said Estanislao Beltrán, a farmer and spokesman for the militia movement, was that the cartel would set the prices for limes, and farmers had no choice but to sell, regardless of prices elsewhere in Mexico or in the United States. This spring, a farmer in Michoacan could make as much as $2 per kilogram of limes, he said, while last year, the cartel-established price was no more than 50 cents a kilo. The extortion did not so much cause the rising prices as it prevented the farmers from benefiting from the increases.

“The Knights Templar determined the price of everything that was sold,” Beltrán said. “Limes, corn, sorghum, anything that generated money. They controlled it all and paid what they wanted.”

Since the militiamen, along with Mexican soldiers and police, have pushed the cartel back, “now there is freedom in the prices,” Beltrán said. Farmers are making more money, and more investment is coming into the lime sector. “This has been a record year.”

Another Michoacan lime farmer and militia commander, Alberto Gutiérrez, agreed that prices rose because of the rain. “Each time it rains, you have to fumigate, and if it rains too much, the disease burns the flower,” he said. “Too much rain, not enough limes.” The abuses of the Knights Templar “doesn’t have anything to do with the prices,” he said.

In general, the high prices have been good for those farmers whose crop survived well enough that they still had limes to sell, especially now that they can benefit from the higher prices without having to sell through a cartel. “The economy is returning, people are coming to invest, there is more security,” said Gutiérrez, who is known as Commander 5.

In recent weeks, lime prices have started to fall, and farmers expect that the supply will continue to increase in coming months and that conditions will return to normal. An era in which lime juice has become a luxury product is likely to pass soon, and here in Mexico, that is not necessarily something to celebrate.

“It was definitely very good for the producer,” Saavedra said, especially for those with enough limes “to benefit from these prices.”

Gabriela Martinez contributed to this report.