Progress in selective harvesting: Lettuce
Head lettuce is a major crop in California with over 100,000 acres harvested annually-accounting for about 60% of the nation's total supply. With labor problems CI certainty when the Mexican bracero program is discontinued, harvest mechanization efforts have taken on new importance. The University-designed experimental machine described in this report is capable of selectively harvesting mature heads of lettuce without' injury, and allows many handling possibilities after cutting. The number of fruits and vegetables harvested by machine has increased rapidly along with changing conditions in farm economics and labar procurement. Tomatoes and prunes are among the most recent of these crops to pass from the experimental to the commercial harvesting stage. Each crop presents special problems in removal of fruit from the plant and in subsequent handling. One problem common to many such crops is the need for selective-and often several-harvests of fruit as it matures, without damaging remaining plants. The University-designed harvesters for lettuce and cantaloupes, described here, show two different approaches to selective harvesting.