Effect of antagonistic Saccharomyces cerevisiae on quality of Redglobe grapes, San Juan, Argentine

MARÍA CRISTINA NALLY; DAVID SEBASTIÁN RADICETTI; VIRGINIA MERCEDES PESCE; LETICIA ANAHÍ RODRIGUEZ; YOLANDA PAOLA MATURANO; MARÍA EUGENIA TORO; FABIO VAZQUEZ

Simposio; III International symposium on postharvest pathology; 2015

Redglobe (Vitis vinifera L.) is a non-climacteric fruit with a short postharvest life. Loss of quality in this fruit is mostly due to its sensitivity to fungal decay as grey and sour rots. The use of yeasts as biocontrol agents has become a sustainable strategy for controlling postharvest diseases of fruit. We determined that S. cerevisiae BSc203 decreased fungal disease incidence in vitro and at field conditions. However there are no data about the effects of this biofungicide on the quality of the table grape. The aim of this work was to evaluate the effect of this biofungicide on quality parameters of Redglobe grapes, in an organic vineyard. Field assay: BSc203 (108 cells/mL) + xanthan gum + glycerol was sprayed in four stages during ripening of the grapes. Matured fruit were harvested and transferred to the laboratory. Bunches were weighed using a digital balance. Berries equatorial diameters were measured with a digital caliper. Total soluble solids (TSS) were determined by hand-held refractometer. Surface color was measured at two points around the equatorial zone of fruit by a colorimeter. Results: BSc203 had no significant effect on weight of bunches, TSS and color of berries. Equatorial diameter of treated berries with biofungicide was significantly higher than the control (p≤0.05). Conclusion: the spraying with BSc203 in organic vineyard before harvest had no significant deleterious effects on the quality of Redglobe grapes. Future research will be done about the effect on size of berries owing to spraying BSc203.