Effects of different iron treatments on wine grape berry quality and peel flavonoid contents

Abstract

In this study, eight‐year‐old wine grape plants (Cabernet Sauvignon) were subjected to five different iron treatments: ferrous sulfate, ferric ethylenediaminetetraacetic acid (EDTA‐Fe), ferric citrate, ferric gluconate, and ferric sugar alcohol, and conventional fertilization. Foliar spraying with clear water was used as the control treatment. The effects of different iron treatments on berry quality and flavonoid accumulation in grape peels were explored. All five iron treatments affected the sugar, acid, and peel flavonoid contents of grape berries, but the contents varied greatly among the different iron treatments. Foliar spraying with iron increased berry sugar content and reduced acid content. In addition, foliar spraying with ferrous sulfate, EDTA‐Fe, ferric gluconate, and ferric sugar alcohol reduced the total anthocyanin, flavanol, and flavonol contents in the peel. The unique flavonoid monomer content of the peel was significantly higher under ferric citrate treatment than under the control and other iron treatments. Moreover, the results showed that foliar spraying with ferric citrate balanced the berry sugar–acid ratio and also increased the anthocyanin, flavanol, and flavonol contents of the grape peel, thereby improving the overall nutritional status of the berries and the final wine quality. The results obtained in this study demonstrate that different iron treatments could improve grape berry quality and clarify the effects of different exogenous iron treatments.

Research progress on iron absorption, transport, and molecular regulation strategy in plants

“…Leaf spraying mainly involves spraying yellowing leaves with iron salt solutions (iron citrate, EDHA-Fe (ethylene diamine tetraacetic acid-Fe), ferrous sulfate and so on), which can improve the yellowing disorder of plants, such as kiwifruit under the treatment of iron citrate and iron amino acid complex, which can Mechanism II of plant root uptake and response to Fe deficiency stress. Ning et al 10.3389/fpls.2023.1190768 effectively improve the chlorophyll content and the content of vitamin C, solids and whole iron in fruits and improve fruit (Wang et al, 2011); the foliar spray of ferric citrate balanced the sugar-acid ratio of grape berries and increased the contents of anthocyanins, flavanols, and flavonols in grape skins (Zhang et al, 2022); after the application of iron fertilizer complex containing iron citrate Fe and EDDHA-Fe, it effectively increased the content of active Fe in peanuts at the flowering hypocotyl and ripening stages and also significantly increased the content of whole Fe in leaves and kernels (Liu et al, 2016); in using different combinations of ferrous sulfate with amino acids (AA), urea (Urea), and EDTA-2Na (disodium ethylene diamine tetraacetic acid) chelated Fe for yellowing apple fruit trees. In the buried bottle and foliar spray experiments, it was found that buried bottle with foliar spray of Fe-EDTA-Urea significantly corrected apple yellowing by increasing the relative chlorophyll content, improving photosynthetic performance, and increasing iron utilization (Guo et al, 2018).…”

Application of different fertilizers to cabernet sauvignon vines: Effects on grape aroma accumulation

“…All treatments were irrigated using a drip irrigation system and management practices such as pruning and pest control were consistent. The chemical properties of the soils (0-40 cm depth) (Supplementary Table S1) were determined as described by Wang et al [24]. The length of the shoot was measured using a 5 m measuring tape.…”

“…However, due to the poor nature of the soil in this region, fertilization is an inevitable means of increasing productivity. Several studies on the effect of fertilization have been published [9,13,[19][20][21][22], but most of these studies are focused on single fertilization, while few studies on the effect of organic fertilizer on grape quality are reported [19,23,24]. Moreover, long-term usage of single fertilizers depletes soil organic matter and causes the imbalance of soil nutrients, affecting grape aroma formation and reducing grape quality, consequently lowering the wine quality.…”