Laura Tourte, UCCE farm management advisor in Santa Cruz County, has studied the economics of mechanical lettuce thinners. Tourte says there is no definitive answer overall on the economic value of mechanical thinners since the technology is relatively new.

“In several cases, we have found the machinery has (economic) potential,” Torte said. “In some cases, the cost of production can be reduced. Hand labor can be reduced.”

To improve the economic value of automated lettuce thinners, she says two advancements are needed – improvements in the machine speed and precision. Some machines run fairly slowly - .5 to 1.5 miles per hour.

Tourte said, “A faster speed is needed to make the machine more efficient.”

She says the quality of the machine thinning job can vary compared to hand-thinned stands. In field experiments, some plants (for keeping) were damaged by the machine or removed which reduced the yield and the grower’s net return. Tourte says this is not the case across the board.