Gruda, N., Division of Horticultural Sciences, University of Bonn, Deichmanns Aue 29, Bonn, Germany, Department for Innovation Promotion, Federal Office for Agriculture and Food, Deichmanns Aue 29, Bonn, Germany
Tanny, J., Institute of Soil, Water and Environmental Sciences, Agricultural Research Organization, POB 6, Bet Dagan, Israel
Tanny, J., Institute of Soil, Water & Environmental Sciences, Agricultural Research Organization, POB 6, Bet Dagan, Israel

The increasing demand by world markets for high quality products has lead more and more agricultural/horticultural crop production systems to protected environments. Covering the crop allows regulation of macro and micro-environments, which facilitates optimal plant performance, extension of the production duration, induction of earliness, and obtaining higher and better quality yields. A spectrum of covered structures is used by growers, depending on the crop, the climatic region and the anticipated benefit. These structures can be generally classified as either screen construction or greenhouse. This chapter comprehensively discusses the effects of the most common types of structures on the major environmental variables: radiation, temperature, humidity, air velocity, ventilation, and carbon dioxide concentration, as well as the effects of these climate modifications on the various crop attributes such as plant growth and development, water and fertilizer supply, and some cultural practices. Moreover, the chapter outlines the objective, measurable aspects that relate to external and internal product quality that are under the influence of intrinsic and extrinsic factors. Finally, some recommendations concerning optimization management in protected cultivations are highlighted, in order to achieve high yields and high quality horticultural products, on time delivery, and energy saving at minimal expense. © 2014 Springer Science+Business Media Dordrecht. All rights reserved.