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

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

Bari

Simposio; III Internation International Symposium on Postharvest Pathology; 2015

Antagonistic behavior of native yeasts: Pichia membranifaciens NPCC1250 andCryptoccocus victoriae NPCC1263 on Botrytis cinerea and Penicillium expansum, wasevaluated in semi-commercial conditions in two organic packinghouse (A and B) ofNeuquén, Argentina. In line-packaging, applications were performed on D?Anjou andPackham?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 ofP. 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 ofCr. victoriae against P. expansum. In (A), P. membranifaciens controlled 83% bothpathogens and Cr. victoriae 100% to B. cinerea. In (B), P. membranifaciens controlled50% 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?Anjoupears, P. expansum was controlled by the three treatments in 82% and B. cinerea byP. membranifaciens and yeast mixture. In general, the mixture of yeasts was moreeffective than alone. While, in Packham?s, P. expansum was completely controlledby Cr. victoriae and the mixture, and by P. membranifaciens alone, in 88%; whileB. cinerea was totally controlled by P. membranifaciens. The number of cells sprayed ofyeast 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 safetechnology based on yeasts, could significantly reduce the incidence of postharvestdiseases of pears under commercial conditions.