Effect of Water Supply on Physiological Response and Phytonutrient Composition of Chili Peppers

Abstract

Water supply is a primary contributor to the growth and phytonutrient composition in chili peppers. Several physiological stress factors can influence phytonutrients in chili peppers, resulting in their differential synthesis. Maintaining the right and exact amount of water through a drip system can promote an effective fruit set and crop quality. Four pepper cultivars (‘Hetényi Parázs’; HET, ‘Unikal’; UNIK, ‘Unijol’; UNIJ and ‘Habanero’; HAB) were investigated under different water supply treatments: RF or rain-fed, DI or deficit irrigation, and OWS or optimum water supply. The two-year experiment was carried out in May 2018 and 2019 under open field conditions. Physiological parameters (relative chlorophyll content, chlorophyll fluorescence, and canopy temperature) were measured during the growth stage and phytonutrients (vitamin C, capsaicinoids and carotenoids) analyzed using high-performance liquid chromatography (HPLC) at harvest in September. The study revealed that, due to higher precipitation and rainfall interruption, increased water supply affected physiological response and phytonutrients in the cultivars. HAB under OWS had a lower response during the growth period when compared to HET, UNIK, and UNIJ. As water supply increased, measured individual carotenoid concentration increased in some cultivars. On the other hand, as water supply decreased, vitamin C and capsaicinoids concentration increased. Even though cultivars responded to the water supply treatments differently, HET exhibited a more uniform and stable composition in all treatments.

Physiological and Productivity Responses in Two Chili Pepper Morphotypes (Capsicum annuum L.) under Different Soil Moisture Contents

“…Mahmood et al [31] evaluated two levels of drought at a 35% and 65% field capacity (FC) to identify the response of capsaicin content and antioxidant activity in different genotypes of chili pepper. Agyemang et al [32] investigated the effect of different water supply treatments: rain-fed (RF), deficit irrigation (DI), and optimum water supply (OWS) on the physiological response and phytonutrients in chili pepper cultivars. Quintana et al [33] exposed habanero pepper (Capsicum chinense Jacq.)…”