Under the right weather conditions, rabbiteye varieties hold up well to mechanical harvesting for the fresh market, but southern highbush varieties generally are too soft, Krewer says.
Also important in evaluating new releases are a concentrated ripening period to reduce the number of harvesting passes, strong root systems that hold up to harvesting machines and fruit that detaches easily with limited ground loss, he says.
Pruning can correct a tendency toward low, spreading branches that hinder mechanical harvesters, but breeding a variety that grows more upright would limit pruning needs.
And, of course, the fruit still must appeal to consumers, Krewer says.
Alto Straughn, owner of Straughn Farms in Waldo, Fla., worked with Florida and Georgia researchers to test releases from their breeding programs last year. He called the results encouraging. For now, Straughn relies on hand-picking his fresh-market berries and machine-harvests for the frozen market. Labor availability will be the overriding reason for fresh-market growers to switch.
“I have five [mechanical] harvesters,” Straughn says. “Why? Insurance.”
But quality issues resulting from both improved varieties and machinery also will play a role, he says. His ideal is losing no more than 5 percent of the packout to softness and other sorting qualities, along with keeping ground loss in the field to no more than 5 percent.
Improvements aid harvesters
Oxbo International Corp.’s Korvan division and BEI International both produce berry harvesters with improvements in the works.
BEI’s newest model is the Black Ice touchless harvester, which uses jets of air to knock berries off bushes, says Rick McKibben, vice president of the South Haven, Mich., company. “It’s much gentler on the fruit,” he says.
The company also offers a new Centipede Scale catching frame that increases fruit capture while reducing bush damage, McKibben says.
Oxbo, headquartered in Clear Lake, Wis., offers two Korvan models for Southern blueberry growers, the 8000 and 7420 harvesters. The company has reduced drop distance on the 8000’s catch frame to retain as much bloom as possible on the berry, says Scott Korthuis, berry market manager.
Similar improvements to the 7420 are coming. An improved catching system is also under development, aiming to lower ground loss and boost yields, he says.
“The biggest area to save money [from reduced fruit loss] is in dropping,” Korthuis says.