Citrus green mould control in stored 'Star Ruby' grapefruit by the use of a bio-control yeast under curing conditions

The biocontrol effectiveness of Candida famata yeast (strain 22D isolated from fig fruit) aginst Penicillim digitatum was investigated when applied separaly or in combination with 95% RH - heat conditioning at 37°C for 72 h. 'Star Ruby' grapefruit was artificially inoculated and kept for 1, 36 or 72 h at 25°C (incubation) before treating with the biocontrol agent alone or in combination with 72 h-heat-conditioning. As control, at each time part of the fruit was teated with 1200 ppm imazalil (standart postharvest treatment for citrus fruits) and part left without treatment. Then, fruit was kept at 8°C (storage)and 20°C (simulated marketing period) for 30 and 7 d, respectively. Untreated inoculated fruit rotteed within the first 15 d of storage, wile when the yeast was applied within the first 36 h post-inoculation, the mould development and infection degree was significantly reduced during this period of time. Treating fruit with the antagonist 72 h after incubation was un-effective and as for control all fruit rotted. After 30 d at 8°C the yeast and heat-conditioning alone resulted un-effective and most fruit rotted, while when combined within the first 36 post-inoculation the efficacy was similar to imazalil even after the simulated marketing period.