Impact of Shading Net Color on Phytochemical Contents in Two Chili Pepper Hybrids Cultivated Under Greenhouse Conditions

Abstract

The objective of this study was to understand the combined effect of shading treatment and harvest time on pungency, ascorbic acid content, market-quality pepper yield, and photosynthetic activity in a yellow 'Star Flame' and 'Fire Flame' F1 hybrid pepper cultivar (Capsicum annuum). Plants were cultivated in a greenhouse under white, red, and green shading nets and compared to those grown under unshaded control conditions. The ascorbic acid and pungency parameters were analyzed by high-performance liquid chromatographic methods. Ascorbic acid, a compound of high nutritive value in pepper, was highest in fruits gathered during the first summer harvest in both hybrids. The ascorbic acid content was found to be further increased in fruits from plants grown under white net shading in both 'Star Flame' and 'Fire Flame'. Total capsaicinoid contents in 'Star Flame' were influenced by the interaction of shading treatment and harvest time ( p = 0.004), with the lowest amounts (241.2-251.5 mg·kg -1 fresh weight) resulting from white and red shading treatments at the early autumn harvest. In 'Fire Flame', both shading treatment ( p = 0.009) and harvest time ( p < 0.001) affected total capsaicinoid contents. We observed significantly higher total capsaicinoid contents in control fruits compared to that resulting from red and green shading treatments at the second harvest, and that resulting from red shading treatment at the third harvest. Analysis of photosynthetic activity revealed a significant and negative correlation between Fv/Fm values and total capsaicinoid contents in both hybrids ( p < 0.001). Based on the obtained results, the harvest of peppers during summer should be promoted to produce fruits with high pungency. OPEN ACCESS AbstractAdditional key words: ascorbic acid, capsaicinoid, chlorophyll fluorescence, pungency

Chili crop innovation: Exploring enclosed growing designs for varied varieties—A review

“…The environmental conditions in which chili is cultivated or the inherent genetic characteristics of each cultivar can be attributed to the variances in capsaicinoid quantity (Table 7) (Hamed et al., 2019). The phytochemical contents of the hybrid chili peppers were significantly influenced by shading net color, with varying colors corresponding to different quantities of phytochemicals (Nagy et al., 2017a). The total capsaicinoids, vitamin C, and relative chlorophyll content were significantly impacted by shading, with shaded plants exhibiting lower amounts than unshaded plants (Zsuzsa, 2018).…”

“…(Agyemang Duah et al, 2021) Stomatal density Shading increase stomatal density. (Nagy et al, 2017a) and total dry weight of chili were observed under the 25% shading (Table 6) (Stamps, 2009). Chili pepper plants' yields tended to decrease under a shade cloth with 50% light exclusion (Sumiyati et al, 2021).…”

“…(Kim et al, 2022) Fruit setting Greenhouses increase fruit setting percentages as they overcome fruit from pests. (Nagy et al, 2017b) Fruit yield Control environment lessens plant stress and increases fruit yield. (Masabni et al, 2016;Nazir et al, 2024) T A B L E 7 Summary from literature findings.…”

Using plastic house shading in the summer improves eggplant and sweet pepper yield

“…Plant height (cm) Nagy et al (2017), Ibrahim (2021) and Zisis et al (2019), who proved the positive role of shading in improving the growth and yield of sweet pepper and eggplant crops.…”

Compatibility between Crops and Solar Panels: An Overview from Shading Systems

“…Nagy et al [35] conducted a study of the production of pepper plants grown in a greenhouse under white, red and green shading and determined that the content of ascorbic acid increased even more in the fruits of plants grown with white shading.…”