A two-year investigation was performed in commercial groves of Campania (Southern Italy) in order to assess the activity of two yeasts (Rhodotorula glutinis, isolate LS-11, and Cryptococcus laurentii, isolate LS-28) and of a yeast-like fungus (Aureobasidium sp., isolate LS-30) against postharvest rots of "Annurca" apple. Fruits were harvested and kept on orchard ground ("melaio") for 20 days to favour the peel reddening by sunlight. The antagonist cells, suspended in water or in a solution of benomyl at a low dosage (10 g/hl of a.i.), were applied on fruits soon after harvesting and twenty days later, before the cold storage. In the second year the antagonists were assayed again with benomyl and also in combination with a mixture of two additives (sodium alginate and marseille-soap). The antagonists significantly reduced fruit rot when combined with a low dosage of benomyl showing an activity comparable to that exerted by the fungicide applied alone al full commercial dosage (100 g/hl of p.a.). All three isolates showed a high survival on apples, both in field and in cold storage, Moreover their presence was accompanied by some reduction of total filamentous fungi populations. The additives were not able to improve neither activity nor survival of the antagonists.
Nel corso di un biennio sono state condotte prove in aziende della Campania per saggiare l'attività di due lieviti (Rbodotorula glutinis, LS11, e Cryptococcus laurentii, LS-28) e di un fungo llevuiforme (Aureobasidium sp., LS-30) contro marciumi postraccolta della mela 'Annurca'. Gli antagonisti, da soli o combinati con benomil a dose ridotta (10 g/hl di p.a.), sono stati applicati dopo la raccolta sui frutti disposti in "melaio" e prima della frigoconservazione. Il secondo anno, per tentare di migliorane la sopravvivenza e l'attività, i lieviti sono stati saggiati anche in combinazione con una miscela di additivi (alginato di sodio e sapone di marsiglia). Utilizzando gli antagonisti in combinazione con il fungicida a basso dosaggio sono state osservate significative riduzioni dei marciumi, paragonabili a quelle determinate dal fungicida utilizzato a dose piena (100 g/hl di p.a.). Gli isolati LS-11, LS-28 e LS-30 hanno mostrato una buona sopravvivenza sui frutti, sia in campo sia durante la frigoconservazione, e hanno indotto riduzioni nella popolazione totale dei funghi filamentosi. L'aggiunta di additivi non ha migliorato la sopravvivenza e l'attività degli antagonisti.
Attività di lieviti antagonisti contro marciumi postraccolta della mela 'Annurca' in condizioni semi-commerciali
LIMA, Giuseppe
;DE CURTIS, Filippo;CASTORIA, Raffaello;
1998-01-01
Abstract
A two-year investigation was performed in commercial groves of Campania (Southern Italy) in order to assess the activity of two yeasts (Rhodotorula glutinis, isolate LS-11, and Cryptococcus laurentii, isolate LS-28) and of a yeast-like fungus (Aureobasidium sp., isolate LS-30) against postharvest rots of "Annurca" apple. Fruits were harvested and kept on orchard ground ("melaio") for 20 days to favour the peel reddening by sunlight. The antagonist cells, suspended in water or in a solution of benomyl at a low dosage (10 g/hl of a.i.), were applied on fruits soon after harvesting and twenty days later, before the cold storage. In the second year the antagonists were assayed again with benomyl and also in combination with a mixture of two additives (sodium alginate and marseille-soap). The antagonists significantly reduced fruit rot when combined with a low dosage of benomyl showing an activity comparable to that exerted by the fungicide applied alone al full commercial dosage (100 g/hl of p.a.). All three isolates showed a high survival on apples, both in field and in cold storage, Moreover their presence was accompanied by some reduction of total filamentous fungi populations. The additives were not able to improve neither activity nor survival of the antagonists.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
