Drawing on the expertise of the University of California's Postharvest Technology Center, this publication discusses commercial uses of modified- or controlled-atmosphere technology which can be used during transport, temporary storage, or long-term storage of horticultural commodities destined for the fresh market or processing.In modified atmospheres and controlled atmospheres, gases are removed or added to create an atmospheric composition around a commodity that is different from that of air. Modified- or controlled-atmosphere technology can be used during transport, temporary storage, or long-term storage of horticultural commodities destined for the fresh market or processing. Chapter 1 discusses how modified- or controlled-atmosphere technology can be used during transport, temporary storage, or long-term storage of horticultural commodities destined for the fresh market or processing.Chapter 2 discusses the ways biologically important gases are sampled, analyzed, and mixed. Since therate of respiration of plant tissue is tightly coupled to its overall metabolic rate-and often inversely proportional to shelf life-the measurement and control of respiration are of vital interest in devising strategies to maintain quality after harvest.Chapter 3 discusses the role of Ethylene in the postharvest life of many horticultural crops. Sometimes this role is beneficial (promoting faster and more uniform ripening before retail distribution) and sometimes it is deleterious (speeding senescence and reducing shelf life). This chapter addresses the properties of this gas and ways to both harness its beneficial effects and avoid undesirable results during the postharvest handling of perishable commodities.