Vineyard calcium sprays induce changes in grape berry skin, firmness, cell wall composition and expression of cell wall-related genes

Exogenous Calcium Delays Grape Berry Maturation in the White cv. Loureiro While Increasing Fruit Firmness and Flavonol Content

“…Accordingly, increased fruit resistance to infection by Botrytis cinerea during storage was achieved by Ca dips after harvest (Fu et al, 2020), an effect that was also reported upon vineyard Ca sprays between fruit set and veraison stages (Amiri et al, 2009;Ciccarese et al, 2013). In line with these observations, Ca sprays during berry development reduce the incidence of microcracks on the fruit surface and the lodging of filamentous fungi in these structures, reducing fruit decay at postharvest (Martins et al, 2020b(Martins et al, , 2021a.…”

“…After centrifuging the extracts at 12,000 × g for 3 min, 300 µL of 0.008% (w/v) murexide reagent was added to 500 µl of the supernatant. Following incubation for 15 min at RT, the OD 490nm was recorded and Ca concentration was determined through a calibration curve of CaCl 2 solution at 2-150 µM (Martins et al, 2020b). The • Brix was determined in aliquots of grape juice using a digital wine refractometer Hanna HI 96813, as described previously (Martins et al, 2020c).…”

“…Tests were performed on a Shimadzu (model AG-IS) equipped with a 50-N load cell and a 1-mm diameter needle. Force-stroke plots were assembled in Trapezium 2.0 Software and results were expressed in MPa, as described previously (Martins et al, 2020b).…”

“…The effects of Ca on fruit texture are connected to its structural function in the cell wall and membranes, mediating crosslinks between pectin molecules, and inhibiting the activity of polygalacturonases responsible for fruit softening (Hocking et al, 2016;Martins et al, 2020b), but a myriad of developmental and stress-response processes mediated by Ca may occur because it is a pivotal secondary messenger (González-Fontes et al, 2017;Aldon et al, 2018). Recent studies reported increased bulk anthocyanin content in berries cultivar (cv.)…”

Potential opportunities of thinned clusters in viticulture: a mini review

“…For Ca 2+ , the increase seems to be faster and more pronounced at maturity, entirely due to the accumulation of calcium in the seeds 55 . High concentrations of calcium help to delay aging, may increase resistance to gray mold ( Botrytis cinerea ), and increase firmness, cell wall composition and expression of cell wall‐related genes 56 . Unripe grape juices contain 0.072% of Ca 2+ , 0.077% of Mg 2+ , 0.034% of sodium (Na + ), 0.085% of K + , 0.39 mg mL −1 of iron (Fe), and less than 0.001 mg mL −1 of zinc (Zn) and copper (Cu) 57 …”