Effects of Cryptococcus laurentii (Kufferath) skinner in combination with sodium bicarbonate on biocontrol of postharvest green mold decay of citrus fruit

The potential of using Cryptococcus laurentii alone or in combination with sodium bicarbonate solution for control of Penicillium digitatum (green mold) on oranges was investigated. Agar disks of C. laurentii NYDA cultures placed on PDA plates seeded with pathogen did not inhibit the growth of P. digitatum. Spore germination of P. digitatum in PDB was significantly controlled in the presence of living C. laurentii cell suspensions. Cryptococcus laurentii significantly controlled green mold on oranges after challenge with 5 x 10(4) spores/ml of P. digitatum. The higher the concentrations of the antagonist, the lower the disease incidence regardless of whether the fruit was stored at 20degreesC for 5 days or 2degreesC for 50 days. The efficacy of C. laurentii for control of green mold was improved when combined with sodium bicarbonate. The combination of sodium bicarbonate and C. laurentii could be an alternative to fungicides for control of postharvest green mold disease on citrus fruits.