A historical photo circa the mid-century featuring women in sunhats harvesting tomatoes with the help of a mechanical harvester

Remaking tomatoes for robotic harvesters

UC Davis plant breeder Jack Hanna and engineer Coby Lorenzen teamed up in the 1950s to invent a machine that could mechanically harvest tomatoes and develop a tomato that would be tough enough to survive a harvester. Numerous attempts failed, but in 1959 they invented the first machine that sorted and loaded processing tomatoes. The new tomato became known as the “square tomato” because its blocky shape prevented it from rolling off the harvester. Nearly all of the tomatoes grown in the U.S. for tomato sauce, paste, ketchup, juice, and other processed foods are harvested by Hanna and Lorenzen’s machine.

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