Effect of shading by coloured nets on yield and fruit quality of sweet pepper

Abstract

The concept of photo-selective netting was studied in a sweet pepper (Capsicum annuum L.) cultivar 'Cameleon' from summer cultivation in south Serbia (under high solar radiation 910 W m -2 , with a photosynthetic photon flux density of 1661 µmol m -2 s -1 ), under four different coloured shade-nets (pearl, red, blue and black) with 40% relative shading. The aim of the study was to determine how different environmental control technologies, coloured shade-nets as net house or plastic-house integrated with coloured shade-nets, could influence plant parameters, production and quality traits in pepper fruits. Shade-grown leaves generally have higher total chlorophyll and carotenoid content than control leaves. Pericarp fruit thickness was significantly higher in peppers grown under red net house (4637.10 µm) and black net house (4609.32 µm) compared to the open field -control (3116.19 µm). The highest concentration of total soluble solids (TSS) was detected in pepper fruits grown under the open field conditions (8.03%). Pepper fruits grown in plastic tunnels had significantly lower TSS content (6.58%). Total acid (TA) content was 0.19 in the control and 0.25 in pepper fruits grown under red nets. The highest concentration of vitamin C was detected in peppers grown in plastic tunnels integrated with red coloured nets (175.77 mg 100 g -1 ). These results show that red and pearl photo-selective nets create optimal growing conditions and increase the total fruit yield as well as the number of fruits with fewer physiological disorders and with thicker pericarp. Photoselective pearl and red nets can be recommended for sweet pepper 'Cameleon' with respect to quality and bioactive compound and can furthermore be implemented in protected cultivation practices.

Effects of Shade Level and Microenvironment on Vegetative Growth, Physiological and Biochemical Characteristics of Transplanted Cucumber (Cucumis sativus)

“…Although the formation of carotenoids in mature fruits does not require induction by light, shaded fruits have lower content of carotenoids (Dorais and Papadopoulos, 2001). The carotenoid content was lowest in plants from open fields and highest in plants covered by black nets (Ilic et al, 2017). This study clearly showed that Chlorophyll a, chlorophyll b, total chlorophyll, and carotenoids increased with increased shade level (Table 3).…”

“…Although shade-grown plants are not directly exposed to sunlight, they produce additional chlorophyll a and b to capture diffuse radiation to produce the carbohydrates needed for the plant to grow, as supported by the results of Beneragama and Goto (2010). Shaded lettuce leaves showed higher total chlorophyll (chlorophyll a and b) content than leaves from unshaded control plants (Ilic et al, 2017). Minimal chlorophyll fluorescence (F 0 ) has been reported to increase with the increase of the irradiance.…”

“…Consequently, exposing fruit to higher temperatures, especially during ripening, leads to an increase in the total soluble solids content (SSC), mainly due to an increase in carbohydrate biosynthetic enzyme activity and increased transpiration (Guillén et al, 2007). Pepper fruits grown in plastic shad nets had significantly lower TSS content when compared with unshaded fruits (Ilic et al, 2017). Conversely, lettuce grown under pearl (and yellow shading nets showed the highest soluble sugar content (Ntsoane et al, 2016).…”

Bell Pepper (Capsicum annum L.) under Colored Shade Nets: Plant Growth and Physiological Responses

“…In this study, shade nets modified light quantity (i.e., PAR) received by bell pepper plants; the effect of shade net treatments on light quality was not measured. Black nets and colored nets have been reported to influence plant growth of bell pepper and other vegetables (Díaz-P erez, 2013; Ilic et al, 2017;Omb odi et al, 2015;Shahak, 2008). In greenhousegrown eggplant, plant height, leaf number, total leaf area, individual leaf area, and plant fresh weight were increased under shading compared with an open field (Aied et al, 2017).…”

“…Although black nets are most commonly used, there has been increased interest in colored nets. Colored nets may influence plant growth, yield, and fruit quality because of their ability to modify both light quality and quantity (Arthurs et al, 2013;Fallik, 2009;Ilic et al, 2017). Regardless of net color, shade nets reduce solar radiation with concomitant reductions in air, plant, and soil temperatures.…”