Enhanced yield and fruit quality of redglobe grapevines by abscisic acid (ABA) and ethanol applications

Abstract

<p style="text-align: justify;"><strong>Aims</strong>: Redglobe has become a popular table grape cultivar in Egypt. However, in warm climates the berries often fail to develop a full red color in addition to having lower total soluble solids (TSS) at harvest time. Here we evaluate the potential for enhancing the quality of Redglobe grapes with applications of abscisic acid (ABA) and ethanol under field conditions.</p><p style="text-align: justify;"><strong>Methods and results</strong>: Abscisic acid (300 mg/L) and/or ethanol (10% v/v) treatments were applied twice (10% and 75% of colored berries) for two seasons (2006 and 2007), and their effect on yield and fruit quality (TSS/acidity, anthocyanin content, firmness, and attachment force) was investigated. The application of ABA did not significantly affect yield when compared to the untreated control, whereas the ethanol treatment, alone or in combination with ABA, resulted in a significant yield increase. Total soluble solids and the ratio between TSS and acidity were increased by all treatments. The highest TSS/acidity ratio resulted from the ABA treatment due primarily to an 18% decrease in total acidity. In this regard, ABA was the most effective treatment. The total anthocyanin content in berry skins increased by approximately 48 and 38% with the ABA and ethanol treatments, respectively. Still, the highest anthocyanin content was obtained with the application of both ethanol and ABA (54% higher than in the untreated control). Berries that were treated with ethanol were markedly firmer and had higher attachment force than those of the other treatments.</p><p style="text-align: justify;"><strong>Conclusion</strong>: The results indicate that the combination of ABA and ethanol is more effective in improving the color of Redglobe grapes but may also increase production efficiency. However, the ethanol treatment alone was more effective in increasing yield and berry firmness and appears to be an alternative to ABA in improving fruit quality in general.</p><p style="text-align: justify;"><strong>Significance and impact of the study</strong>: The results obtained in this study will be useful to improve the fruit quality of Redglobe grapes in the field under warm conditions.</p>

Early marketable yield and better berry skin color of ‘Redglobe’ grapevines cultivar grown under warm climate by application of Sulis®

“…Yield and cluster weight is mainly depending on berry weight. The results of berry weight were in similar to noticed by Peppi et al (2007a), Omran (2011) and Deng et al (2019) for 'Redglobe', Peppi et al (2007b), Peppi and Fidelibus (2008), Lurie et al (2009) and Ferrara et at. (2013) for 'Crimson Seedless' grapes, and Kishino and Roberto (2007) for 'Rubi' grape, when they applied PGRs.…”

“…The conversion of these L*, a*, and b* to lightness, chroma, and hue showes into lower lightness and hue values and in general. Reductions of L*, C* and h˚ in grape skin, due to application of ABA, ethephone or both together, were previously observed by Kim et al (1998), Peppi et al (2006); Lurie et al (2009), Omran (2011), Ferrara et al (2013), and Olivares et al (2017 . But, Cantín et al (2007) found that h˚ and L* values were not differed than the control when ABA or ethephone were applied.…”

“…Under these conditions, Total soluble Solid percentage in berries might reach to commercial level (14-16 Brix) without suitable color appearance (Lurie et al, 2009). The same climate patterns are in Egypt (Omran 2011;Lo'ay 2017). Temperature rising (global warming) is likely to continue (Agrawala et al, 2004), making proper coloration of red grapes is more difficult.…”

“…This situation gave a great opportunity to the grower to earn better money. But, fulfillment of commercial standard coloration, under recently recorded high temperature, is a big challenge (Omran 2011).…”

Abscisic acid and ethephon treatments applied to ‘Verdejo’ white grapes affect the quality of wine in different ways

“…The soluble solids content in harvest musts were similar in grapes treated with ABA and untreated (Table 2), consistent with other authors' findings (Amiri and Parseh, 2011;Delgado et al, 2004). Nevertheless, as with ethephon, ABA tended to decrease the TA and raise the pH of the must in all seasons studied, which is consistent with previous results obtained in table grape cultivars (Omran, 2011;Peppi et al, 2007;Reynolds et al, 2016;Yamamoto et al, 2015). However, most studies in the literature have not observed changes in must TA associated with the application of ABA (Cantin et al, 2007;Delgado et al, 2004).…”