RAPISARDA Viviana Andrea
congresos y reuniones científicas
Control of lemon green mold caused by an imazalil-resistant Penicillium digitatum isolate
CERIONI, L.; RAPISARDA, V. A.; PRADO, F. E.; RODRÍGUEZ-MONTELONGO, L.
Carlos Paz (Córdoba)
Congreso; XLIV Reunión Anual de SAIB; 2008
P. digitatum is the causal agent of citrus green mold. To avoid this pathogen, lemons have been treated with fungicides (mainly imazalil), leading to the proliferation of resistant strains and the increase of toxic residues in the fruit. International markets have implemented strict limits on such residues and thus, is urgent to find alternative methods for decay control. We standardized, in vitro, an oxidative sequential treatment (OST) to kill P. digitatum conidia. It consists in 2-min incubations of conidia at 20ºC: first with NaClO and then with H2O2 and CuSO4. Here, we analyze if the OST and some variations of it are effective on an imazalil resistant isolate. The effect of the treatment was checked in vitro by viability on plate and by infectivity on lemon fruits. The OST was effective against imazalil-resistant isolate showing a total loss of viability and infectivity. Moreover, the decay control was evaluated by in situ applications of OST, in lemons inoculated (24 h before) with non-treated conidia. The decay was significantly delayed in the fruits subjected to in situ treatment in comparison with those treated with water. Additionally, the in vitro protocol was improved by incubations at 42ºC. Our OST may have a potential application for postharvest disease control, and the procedure at 42ºC would be suitable since this temperature activates natural defenses of lemons.