In 1970, some 10 percent of California's cling peaches were mechanically harvested. Mechanization results in substituting machine investment for labor. For example, an estimated $25,000 invested in a mechanical harvester substitutes for 3,962 hours of labor a year on an 80-acre peach farm. The economical point for purchasing a mechanical harvester is an estimated 37 acres of mature peaches yielding 14 tons an acre. This equal-cost peach acreage is the point where hand and machine harvest costs break even. A relative 25-percent gain in labor costs from 1970 wage rates would lower the equal-cost point to 29 acres. Rate of adopting mechanical harvesters depends on the economic feasibility of such acquisition, processors' attitudes toward handling machine-harvested fruit, and their capabilities for such handling. Mechanization of cling harvest would call for a series of adjustments by growers and workers. Growers would have to increase investments in machinery and change some cultural practices. Some workers would have to acquire higher skills, while others would lose their jobs and need retraining for new ones.