Food suppliers are being forced to adapt as the COVID-19 outbreak has shut restaurants, bars and schools and is sending shoppers looking for reliable sources for goods from meat to vegetables. Many want to steer clear of supermarkets that have been picked over by shoppers, unnerved by the highly contagious respiratory virus.

Farmers said they had supplies and were seeing an uptick in demand for home deliveries in areas where grocery delivery services like Instacart and Amazon.com's AmazonFresh are not widely available.

"We're finding that these farms have a lot of opportunity to step in and prove their value now," said Dan Miller, chief executive of Steward, a company that provides capital to sustainable farms and helps them set up e-commerce platforms.

In Alex, Oklahoma, married farmers Carrie and Joe Chlebanowski began making "porch deliveries" on Sunday, after suspending sales at a weekly farmers market in Oklahoma City over health concerns. They delivered lettuce and other greens to about 16 customers and also opened a stand to make sales at their farm.

"People are recognising that local farms like ours have access to food and have the ability to provide them things that they don't have to go into the grocery store to get," Carrie Chlebanowski said.

More farmers are focusing on direct-to-consumer sales amid declining demand from local restaurants. The nation's biggest meat processors like Tyson Foods Inc have also scrambled to shift their supplies to grocery stores.

The pandemic could cost local and regional food systems, including farmers markets, $688.7 million in lost sales from March to May, according to researchers from Colorado State University and the University of Missouri. That could lead to a total economic loss of up to $1.3 billion, they said.

The Congressional Research Service estimated local US food sales, including farm sales directly to retail stores, at $11.8 billion in 2017.

Chad Ward, who raises chickens and crops near Pawnee, Oklahoma, said he had seen an explosion in demand for deliveries of frozen meat. He is still making trips to the Oklahoma City farmers market, although home deliveries allow consumers to practice social distancing to help counter the spread of the coronavirus.

"People have turned to us in the same way that we have always depended on them," Ward said. "It's caused us all to lean in on each other."