Effect of postharvest treatment and quarantine procedure on organic table grape 'Italia'
Mediterranean fruit fly - Medfly, Ceratitis capitata (Wiedemann) - is regarded as one of the most destructive agricultural pests worldwide causing severe effects on trade to sensitive local and international markets. The establishment of a quarantine protocol for organic table grapes is essential to overcome phytosanitary barriers and to have open access for organic table grape to foreign markets. An experiment to evaluate the mortality of Ceratitis capitata was carried out in 2010-2011. Application of cold treatment at 1±0.5°C for 11 days was performed as a quarantine treatment against Medfly. However, during cold storage the grape quality might decrease due to the development of Botrytis cinerea. Organic table grapes are more vulnerable to fungi infestation as it is not permitted to treat organic commodities with fungicides. Quality assessment of 'Italia' table grapes treated with CO2 (30% for 48 h) and continuous O3 (0.8-1.2 ppm) for the control of the development of grey mould was carried out in a cold room (0±1°C and 90-95% RH) for 27 days and at 12°C for 2 more days to evaluate shelf life. The evaluation was done weekly through chemical, physical and sensory analysis. Mortality assessment of Medfly showed that cold treatment is an effective quarantine method in postharvest. The most tolerant stage resulted first instar larvae requiring more than 11 days at 1±0.5°C, followed by second and third instar larvae. Most susceptible stage was pupae, which requires less than 7 days to achieve 99% of mortality. Quality assessment of table grape showed no differences among treatments, however, CO2 increased the volatile contents without damaging the quality and treatment with O3 preventing lightly the development of B. cinerea up to 27 days of storage plus 2 days of shelf life (12°C).
Lamaj, F., Ismaili, K., Lovino, R., Simeone, V., Verrastro, V., Baser, N. and Tarricone, L. (2016). Effect of postharvest treatment and quarantine procedure on organic table grape 'Italia'. Acta Hortic. 1144, 259-266
Ceratitis capitata, Medfly, Botrytis cinerea, cold quarantine treatment, cold storage, ozone, carbon dioxide