Preharvest Applications of Oxalic Acid and Salicylic Acid Increase Fruit Firmness and Polyphenolic Content in Blueberry (Vaccinium corymbosum L.)

Abstract

Blueberry exports that imply transport times of more than 25 d deteriorate their quality. The use of elicitors in preharvest has shown positive effects on the quality of berries such as grapes. The objective of this study was to evaluate preharvest applications (21, 14, and 7 d before harvest) of oxalic acid (OA) and salicylic acid (SA) on fruit firmness and phenolic compounds in blueberry. The treatments of 0, 2, and 4 mM OA in ‘Kirra’ and 0, 2, and 4 mM SA are in ‘Stella blue’. With the earlier preharvest application, ‘Kirra’ presented better firmness than ‘Stella blue’; however, 2 mM OA and SA in both cultivars increased fruit firmness, maintaining its weight and diameter with respect to the control. It should be noted that the treatment with 2 mM SA generated a 100% increase in polyphenolic content and antioxidant capacity (p < 0.05) in ‘Stella Blue’, with values close to 140 mg gallic acid 100 g−1 and 80 mg 100 g−1 fresh weight (FW), respectively. In Kirra, OA treatments did not have a significant impact on the polyphenol content, but 4 mM OA increased by 100% and 20%, total anthocyanin and antioxidant capacity of blueberry fruit, respectively. Based on our results, three pre-harvest applications of OA and SA during the fruit development until the beginning of ripening improve fruit firmness by up to 20% at different times of harvest.

Novel Approach to Organic Mulching from Natural-Based Solutions to Enhance Soil Health and Functional Value of Calafate Fruit

“…As for leaf temperature, the results indicate that the different mulches did not have a significant effect. This suggests that the ambient temperature in the study area, with maximums of up to 30 • C at the time of the measurements, may not have been a determining factor in this parameter [41]. However, when analyzing the soil surface temperature, it was observed that the GEO mulch showed a higher temperature compared with the control, while it presented similarity in this aspect with the other mulching treatments.…”

Pre-Harvest Salicylic Acid Application Affects Fruit Quality and Yield under Deficit Irrigation in Aristotelia chilensis (Mol.) Plants

“…Our results agree with Giménez et al [ 45 ], who showed that 0.5 mM SA application significantly increased TP (by about 20%) and AA (by about 50%) in fruits of P. avium . Recently, Retamal-Salgado et al [ 51 ] showed that 2 mM SA application increased by 100% TP, AA and ANT in V. corymbosum fruits. In contrast, we did not observe changes in ANT between SA treatments in DI plants.…”