Lemon post-harvest decay control by natural products
Adele, S., Giuseppa, S., Giuseppe, P., Francesca, B. and Francesco, C.
Program and Abstracts, 11th International Citrus Congress (ISC Congress), 26-20 October 2008, Wuhan, China. 333 pages.
2008
บทคัดย่อ
Lemon post-harvest decay control by natural products
Postharvest diseases of lemon fruits represent one of the most severe sources of production loss. They are controlled by imazalil (IMZ), thiabendazole (TBZ) and sodium ortho-phenil-phenate (SOPP) registered fungicides for postharvest treatments. Nowadays, the chemical control is becoming more restricted for environmental concerns and development of fungicide-tolerance strains of fungal pathogens. In the last few years a renewed interest in alternative methods for postharvest decay control has been increasing and the research for natural products has provided encouraging results. The aim of this research has been the in vitroand in vivo evaluation of six essences (garlic, cloves, oregano, mint, geranium and eugenol) and three mineral products (sodium bicarbonate, potassium metabisulphite and kaoline) to control Penicillium digitatum Sacc. and Phytophythora citrophthora (R. e E. Sm.) Leonian, the main agents of postharvest decay in lemon fruit. In 2006-2008, in the in vitro assay, the essences and mineral substances were tested at different concentrations using the Grover and Moore method. In the in vivo trial, the products were tested on mature lemons both on intact and wounded fruits, the latter previously infected with Penicillium spores and a Phytophthora colony fragments. In both experiments fruits were sprayed with the products at different concentrations, air dried and stored at 5°C for 5 weeks. In in vitro results, oregano, geranium and cloves essential oils showed a better P. citrophthora inhibition at all concentrations, while garlic and mint oils were effective only at the highest concentrations. only mint essential oil showed a good inhibition of P. digitatum colony at all concentrations. Geranium, oregano, eugenol, sodium bicarbonate and potassium metabisulphite in vivo treatments on intact fruits showed a higher control against both fungi as well as IMZ treatment. on artificially infected lemons, the results showed the efficacy of IMZ compared to a light inhibition activity of the natural products. Among them, a better inhibition on Penicilliumwas obtained by mint essential oil, while geranium, cloves, oregano and eugenol oils were more effective against Phytophthora.