Claire Parker for The Washington Post

KAIROUAN, Tunisia Mohamed Sid is waiting for the lights to go out — not for lack of oil but because there is too much of it.

Unusually heavy rains have yielded a bumper crop of olives across Tunisia, and that oversupply has sent the price of olive oil plummeting, provoking a crisis in one of the world’s largest producers.

Sid’s olive trees in the inland province of Kairouan have borne twice as many olives as usual, about 30 metric tons, but he says his earnings are just half of those from last year. He cannot cover his costs or pay the electric bill, and he worries that the electricity company will soon pull the plug.

“I’m fed up, and I wrote on the farm wall ‘For sale’ because I can’t stand this anymore,” he said.

With its largely chemical-free orchards, Tunisia is the largest exporter of organic olive oil in the world. Tunisian olive oils have won medals at international competitions in London and Los Angeles.

Yet Tunisian olive oil remains little-known to many foreign consumers. That is partly because it is largely exported in bulk, mostly to Italy and Spain, said former commerce minister Omar Behi. There, some gets mixed with local oils and sold in grocery stores around the world under Italian or Spanish brand names.

Claire Parker for The Washington Post

Tunisia’s production of olive oil has doubled in a year, to about 350,000 metric tons, turning the country into the world’s second-largest producer after Spain. This glut has exacerbated the effects of what was already a global slump in olive oil prices.

Tunisian producers are reporting dramatic price drops, with a kilogram of freshly produced virgin olive oil on average fetching about $1.50 in January, according to National Olive Oil Office chief executive Chokri Bayoudh. Prices for raw olives have dropped even more sharply, meaning small growers like Sid who do not make their own oil are bearing the brunt.

“It’s a catastrophe, especially for small farmers,” said Faouzi Zayani, vice president of national farmers union Synagri.

Olive oil constitutes half the country’s agricultural exports. More than 300,000 farmers rely on olives for at least some income, and the olive sector employs nearly 10 percent of the entire workforce, according to the Agriculture Ministry.

The Phoenicians introduced olives to the area nearly 3,000 years ago. Empires came and went, but the olive tree endured as a hallmark of daily life and cultural heritage. Proverbs herald its bounty, and olive oil remains a popular home remedy for sore throats and dry skin.

“There is no Tunisia without olive trees,” said Selim Ben Ali, a 22-year-old seasonal worker who spends each harvest camped out on a Sfax orchard.

Good harvests usually mean cash for weddings or home repairs, farmers say. But this year, they are sinking into debt. Some cannot afford to work their land, jeopardizing future crops. The crisis is having ripple effects as hard-pressed farmers are forgoing annual shopping trips for clothing or household items.

Claire Parker for The Washington Post

The current crisis began in Spain, where surplus olive oil from last season’s huge harvest saturated the market before this season even began. Olive oil prices around the world plummeted, and farmers across Spain staged protests.

Climate change, which is causing intense droughts punctuated by seasons of heavy rain, has made Mediterranean olive production even more unpredictable. More than 90 percent of Tunisia’s olive trees are nonirrigated, leaving Tunisia especially vulnerable.

Abdelmajid Ezzar, president of the Tunisian Union of Agriculture and Fisheries, said low prices have hit those in the country’s poorer interior regions particularly hard. On Adel Jamaoui’s farm outside Kairouan, withered black olives litter the ground under trees that Jamaoui cannot afford to harvest.

In December, angry farmers blockaded the Agriculture Ministry in Tunis, demanding that the agriculture minister resign and the government stabilize prices.

The government responded by buying up some of the surplus and subsidizing exporters’ transportation costs. In January, it approved an emergency plan to store 100,000 tons of olive oil and pay a premium to producers and exporters. The central bank, meanwhile, has urged banks to continue extending credit to those affected. Tunisian officials have engaged in olive oil diplomacy, calling on foreign diplomats in Tunisia to promote the country’s oil back home.

Claire Parker for The Washington Post

“The state has taken all necessary measures,” said Boubaker Karray, the former agriculture minister’s chief of staff. (A new government was formed late last month with new ministers.) He said the government is encouraging irrigation and has readied a fund to help farmers who face losses because of climate change.

In recent decades, successive governments have invested in expanding the olive oil sector to develop impoverished regions, reduce the trade deficit and inject foreign currency into Tunisia’s struggling economy. The government has also ramped up incentives in recent years for producers to bottle their olive oils — which increases their value — and promote them abroad.

The massive harvest this season has made the search for new markets more urgent. The European Union maintains a 56,700-ton annual quota for duty-free olive oil imports from Tunisia, aside from the quantity that European importers buy and re-export.

Tunisia has asked the E.U. to raise the quota, and E.U. officials have said they are open to discussing this only as part of wider trade talks. When the E.U. temporarily raised the limit in 2015, it encountered fierce pushback from Italian producers and politicians.

So Tunisia is looking to Asia, Africa and the United States instead. Tunisia now supplies the United States with 5 to 15 percent of its imported olive oil, according to the U.S. Commerce Department.

Now, Tunisia could be looking ahead to another year of losses — this time resulting from too little rain. Eyeing cloudless skies and dusty ground, farmers in Sfax and Kairouan say a recent drought portends a poor harvest next season. Last month, Tunisia’s minister of religious affairs called on imams across the country to pray for rain.

“The destiny of Tunisia is a destiny of olive oil,” said Bayoudh, the olive oil office head. “We don’t have a choice.”