Don Worthington

Clemson researchers test bagging peaches – while on the trees

Baskets of August Lady peaches line the front of the Peach Stand near Fort Mill.
Baskets of August Lady peaches line the front of the Peach Stand near Fort Mill.

Will plastic bags revolutionize the fruit growing industry?

Clemson University researchers have experimented with putting plastic bags over young peaches – just two to three weeks after the bloom sets and the trees are thinned – and keeping them on until the harvest.

Initial research suggests the idea has merit.

The bags address the two major problems with peaches, pests and pesticides.

Bagging the peaches keeps insects off the fruit and reduces the reliance on pesticides. It also could limit skin disorders caused by pesticide residue or heat stress.

Tests by Clemson researchers shows that fruit size and weight are about the same as conventionally grown peaches when bagged. But the color of bagged peaches is not as “blush red” as unbagged peaches because they do not receive as much direct sunlight.

Clemson researcher Guido Schnabel said bagging peaches could create several niche markets.

Bagging peaches, he said, “could be a key component for organic producers who currently don’t really have the tools to produce quality fruit.” There is only one organic peach grower in the state, he said.

Another niche market could be homeowners with a few fruit trees.

A third option could be conventional peach growers setting aside several acres for bagged peaches.

York County growers were both intrigued and skeptical of the idea.

Peach grower and farmer Arthur Black of York said the idea is similar to a concept used to grow strawberries where covers are used to protect the berries.

But York County growers’ first questions were about the costs – from the price of the bags to the amount of labor needed to bag peaches.

Schnabel said the per-acre cost of the bags – imported from China – is about $1,200. While the bags can be put on in about 10 seconds, Schnabel estimates the per-acre labor cost is about $1,200. The investment of $2,400 an acre or more, growers said, would require a premium price for the peaches.

Initial market research by Clemson indicates consumers may pay from 20 percent to as much as 80 percent more for peaches free of chemicals.

Other growing techniques studied by Clemson could benefit local peach farmers. Black cited a Clemson extension service study of how China uses greenhouses to cultivate peaches and other fruits and flowers.

“Protected cultivation” as it is called, uses simple, energy-efficient solar greenhouses. China has about 30,000 acres of greenhouses set aside for peaches and nectarines, according to Clemson researchers. The greenhouses can produce fruit one year after trees are planted, and fruit is ready for harvesting up to two months early, getting higher market prices. The greenhouses also reduce the need for, and cost of, pest control measures.

Another possibility, in its early stages, is a weather tracking system that helps growers determine the best time to spray for fungus. Ron Edwards, manager of the Springs Farms in Fort Mill, has a unit that is used for strawberries. The weather station records temperatures, wind speeds and humidity, and then sends the data to Florida for analysis.

“The result is we don’t spray as much as we used to,” Edwards said.

Whether this system could be adapted for peaches is unclear.

What is clear is South Carolina peach growers, regardless of location, are willing to try ideas that lessen their two biggest challenges, the cold and the heat.

If it’s too cold the young peach blooms die. If it’s too hot fungus can rot the peaches.

This past year’s chilly temperatures early in the growing season cost local peach growers from 50 percent to 80 percent of their crop. The recent string of hot weather hasn’t helped either.

Nonetheless, growers are reporting they’ve recently harvested Jersey Queen, Monroe, Autumn Prince, Concord and White Hale varieties, which should keep fresh peaches on the market for at least another month or so.