Lemon Post-harvest Decay Control by Natural Products

摘要

Postharvest diseases of lemon fruits represent one of the most severe causes of loss production. They are usually controlled with chemical fungicides which use is becoming more restricted for environmental concerns. The aim of this research has been the in vitro and in vivo antimicrobial evaluation of six essences (garlic, cloves, oregano, mint, geranium and eugenol) and three mineral products (calcium bicarbonate, metabisulphite and kaoline) against Penicillium digitatum Sacc. and Phytophthora citrophthora (R. e E. Sm.)Leonian which are the main responsible agents of postharvest decay in lemon fruit. In 2006 -2008, in the in vitro test, the essences and mineral substances were evaluated at different concentrations. In the in vivo trial the products were tested on mature lemons both on unwounded and Penicillium and Phytophthora infected fruits. In both experiments fruits were sprayed with products at different concentrations. In the in vitro experiment, oregano, geranium and cloves essential oils showed a better inhibition against P. citrophthora at all concentrations, in comparison with garlic and mint oils, that were effective only at the highest concentration. Only oregano essential oil and eugenol showed a good inhibition against P. digitatum at all concentrations. Geranium, garlic and metabisulphite as well as IMZ in vivo treatments on unwounded fruits were able to control both fungi. The results on artificially infected lemons showed a higher IMZ effectiveness and a light inhibition of the natural products.