Effects of colored shading nets on quality parameters and phytochemical profile of bell peppers (Capsicum annuum L.)

Abstract

The majority of Bell pepper production is carried out under protected agriculture conditions. Shading nets provide protection from high light intensities and environmental hazards. The use of photo-selective shading nets is an emergent agro-technological technique that pursues crop quality improvement by modifying the light environment and plant microclimate. Blue, gray, and black shading nets were used to test their effect on the phytochemical profile and quality parameters of red, orange, and yellow bell peppers (cv. 'Ocelot', 'Orbit', and 'Sabour' respectively) and compare them with fruits grown under unshaded conditions. Modified light characteristics under the photo-selective nets slightly enhanced the fruit weight and size of the three cultivars. The blue shading net favored the accumulation of -carotene in the three cultivars and enhanced the total phenolic content of ‘Sabour’. The gray shading net increased the total phenolic content of ‘Orbit’ and the antioxidant activity of ‘Ocelot’. The black shading net incremented the antioxidant activity of ‘Orbit’ and ‘Sabour’. Unshaded conditions increased the total phenolic content of ‘Ocelot’. This cultivar, ‘Ocelot’, showed the highest -carotene content and antioxidant activity among cultivars while ‘Sabour’ had the highest phenolic content. Temperature and relative humidity under the shading nets and fruit firmness were not significantly affected by the treatments. The differences in phytochemicals and quality traits due to color of shading net were minor for most of the fruit parameters evaluated.