Awatef Mahmud, a 53-year-old mother of five who sat on a nearby stoop waiting for her bread to cool, said higher prices had led to dietary changes for her family. “Instead of buying one kilo of meat every week, we buy a half a kilo,” she said. “People used to buy pasta to make for their kids. But now that it’s four and a half pounds,” she said, referring to the currency, “they give them bread instead.”

Economists say that rather than seeking to become self-sufficient with food, countries in this region should grow crops for which they have a competitive advantage, like produce or flowers, which do not require much water and can be exported for top dollar.

For example, Doron Ovits, a confident 39-year-old with sunglasses pushed over his forehead and a deep tan, runs a 150-acre tomato and pepper empire in the Negev Desert of Israel. His plants, grown in greenhouses with elaborate trellises and then exported to Europe, are irrigated with treated sewer water that he says is so pure he has to add minerals back. The water is pumped through drip irrigation lines covered tightly with black plastic to prevent evaporation.

A pumping station outside each greenhouse is equipped with a computer that tracks how much water and fertilizer is used; Mr. Ovits keeps tabs from his desktop computer.

“With drip irrigation, you save money. It’s more precise,” he said. “You can’t run it like a peasant, a farmer. You have to run it like a businessman.”

Israel is as obsessed with water as Mr. Ovits is. It was there, in the 1950s, that an engineer invented modern drip irrigation, which saves water and fertilizer by feeding it, drop by drop, to a plant’s roots. Since then, Israel has become the world’s leader in maximizing agricultural output per drop of water, and many believe that it serves as a viable model for other countries in the Middle East and North Africa.

Already, Tunisia has reinvigorated its agriculture sector by adopting some of the desert farming advances pioneered in Israel, and Egypt’s new desert farms now grow mostly water-sipping plants with drip irrigation.