Efficacy semi-commercial trials of native yeasts: Pichia membranifaciens and Cryptococcus victoriae on conservation medium and length pears, in northern Patagonia, Argentina.

LUTZ, M.C.; LOPES,C.; SOSA, M.C.; GRAMISCI, B.; SANGORRIN,M.

Bari

Simposio; III International Symposium on Postharvest Pathology Using Science to Increase Food Availability; 2015

UNIBA- ISHS

Antagonistic behavior of native yeasts: Pichia membranifaciens NPCC1250 and Cryptoccocus victoriae NPCC1263 on Botrytis cinerea and Penicillium expansum, was evaluated in semi-commercial conditions in two organic packinghouse (A and B) of Neuquén, Argentina. In line-packaging, applications were performed on D'Anjou and Packham's pear fruit. Yeast biomass was produced in cane molasses (12.8 g/L) and urea (0.6 g/L). About 400 kg of fruit were sprayed with yeast suspension (1011CFU/mL).Treated fruit was packaged and stored in commercial storage chamber (-1/0°C, 95% RH). During 2012, the effect of yeasts alone and with CaCl2 (2% w/v) was evaluated. At 90 days, in (B) on D'Anjou pears, yeasts with CaCl2 reduced the incidence of P. expansum more than 60% and Cr. victoriae plus CaCl2 fully controlled to B. cinerea. Packham's pears were evaluated at 160 days. The CaCl2 improved the antagonism of Cr. victoriae against P. expansum. In (A), P. membranifaciens controlled 83% both pathogens and Cr. victoriae 100% to B. cinerea. In (B), P. membranifaciens controlled 50% and 56% the incidence of B. cinerea and P. expansum, respectively; while, Cr. victoriae controlled 72% of B. cinerea. In 2013, the effect of yeasts (1011 CFU/mL) alone or in mixture (1:1) with CaCl2 2% (w/v) was evaluated. At 90 days, in D'Anjou pears, P. expansum was controlled by the three treatments in 82% and B. cinerea by P. membranifaciens and yeast mixture. In general, the mixture of yeasts was more effective than alone. While, in Packham's, P. expansum was completely controlled by Cr. victoriae and the mixture, and by P. membranifaciens alone, in 88%; while B. cinerea was totally controlled by P. membranifaciens. The number of cells sprayed of yeast was reduced by the delivery system employed in at least two orders of magnitude. The yeasts colonized the fruit surface, reaching 107 and 108 CFU/cm2 of fruit. This safe technology based on yeasts, could significantly reduce the incidence of postharvest diseases of pears under commercial conditions.