High efficacy postharvest plant-based green treatments for citrus decay control

The postharvest control of citrus main pathogens (Penicillium digitatum and Penicillium italicum) is mainly dependent on the use of synthetic fungicides, such as imazalil, o-phenylphenol, thiabendazole or pyrimethanil, among others. However, the widespread use and presence of pesticide residues on fruit is becoming gradually questioned and restricted because of concerns about environment, consumer health and development of resistances, which has increased the demand for residue-free fruit and/or BIO-certified fruit. As a result, alternative decay control methods are needed, and treatments based on natural products, such as plant extracts, or inorganic salts, the so called “green chemistry” treatments, could be an alternative. However, to be used at industrial level, these treatments should have high decay control efficacy. “Green chemistry” treatments are usually less effective than conventional fungicide treatments, have a higher variability and little residual effect over time. Citrosol has developed a “green” drencher/water tank treatment, based on the plant-based proprietary formulation Greencide^®, with high efficacy in decay control, reduced variability, and residual effect even in prolonged storage periods. An efficacy range of 80-100% after 7 days of shelf life test (20°C, 85% RH) was obtained in a large set of independent experiments applying Greencide^® treatments on fruit artificially inoculated with Penicillium digitatum, while the reference conventional treatment with imazalil had an efficacy range of 89-100%. The Greencide treatments showed higher efficacy and less variability than current alternative treatments based on inorganic salts and food additives, such as the ones based on peracetic acid + sodium bicarbonate (BIO-certified). These treatments complemented with Citrocide^® PC peracetic acid disinfection (BIO-certified) in the washing machine and a proper waxing with PlantSeal^® coatings (BIO and Vegan certified), will contribute to achieve excellent arrivals to distant destinations using only “green chemistry”.