Olive trees are notoriously resistant to mechanical harvest, but UC researchers are making steady progress toward developing a system that will get 80 percent of the fruit off trees without hiring an expensive hand crew. The research goal and progress were shared in a Capital Press story by Hank Shaw about a recent field day at the UC Nickels Soil Lab near Arbuckle.

Table olives are "devilishly difficult to pick," the story said.

• Olives bruise easily and bruised olives don't cure properly.
• Olive trees tend to be wispy, which limits the ability of shaking machines to clean off a tree that just sways.
• Olive tree trunks are typically knobby and shakers rub the bark off those knobs, opening the tree to disease.

Researchers are trying to mechanize olive harvesting because hand-picking can cost growers more than half of their gross returns.

"Manually harvesting now is perhaps $450 a ton," the story quoted UC Davis pomologist Louise Ferguson. "And on a good year (growers) will get $650 a ton."

Growers learned at the field day they will still need to hire human workers to harvest olives for at least another year or two.