Josefa López-Marín - Department of Crop Production and Agri-Technology, IMIDA, C/ Mayor s/n. ۳۰۱۵۰ La Alberca-Murcia, Spain.
Amparo Galvez - Department of Crop Production and Agri-Technology, IMIDA, C/ Mayor s/n. ۳۰۱۵۰ La Alberca-Murcia, Spain.
Francisco del Amor Saavedra - Department of Crop Production and Agri-Technology, IMIDA, C/ Mayor s/n. ۳۰۱۵۰ La Alberca-Murcia, Spain.
Francisco Javier Manera Bassa - Department of Physics and Computer Architecture, Miguel Hernandez University, Orihuela, Alicante, Spain.
Julio Carrero-Blanco - Department of Mechanical, Materials and Manufacture Engineering, Universidad Politécnica de Cartagena, Cartagena, Spain.
Jose Brotons Martínez - Department of Economic and Financial Studies, Miguel Hernandez University, Elche, Alicante, Spain.

Photoselective nets are used to protect horticultural plants from sunburn and prolong the cropping period in conditions of excess light. In this work, we studied the influence of four photoselective shading nets (Pearl ۳۰, Red ۳۰, Silver ۳۰, Red ۴۰), a standard black-colored net (Black ۳۵), and a control (no cover) on the evolution of color during the ripening of two types of pepper, namely, Lamuyo and California. For this purpose, the evolution of the colors of the fruit was followed from the beginning of their formation until the harvest, and was correlated with the total radiation and the temperature. The plant material used were peppers of the California type -cultivars Bendigo and Cayetano- and of the Lamuyo type, cultivars Alcudia and Pompeo. The results showed that the rate of change of the pepper coloration depended on the net used in the greenhouse. The speed of the change in color from green to red was more dependent on the cultivar and the total radiation, as conditioned by the different photoselective nets, than on the type of pepper. The greatest differences were between the control (without a net) and the black net, the increase in the red color of the peppers being faster in the former. Radiation values below ۷۵ W m-۲ or greater than ۱۱۰ W m-۲ negatively affected the yield. The temperature below the net was not affected significantly by the type of net, and thus its effect on the different cultivars was similar.

CIELAB, ΔE, Radiation, Sweet pepper color.