We have been exporting pomegranates from
India to Europe. The first container arrived in good shape, but thereafter each container had different problems including white mold, some internal rotting, inking, and brown spots in the interior. Any ideas on how to prevent this? (F.R.)
The fungus may be grey mold caused by Botrytis cinerea, which is a limiting factor to storage of pomegranates unless they are treated with an approved fungicide or kept in a 15% carbon dioxide-enriched atmosphere (fungistatic atmosphere similar to what is used commercially on strawberries). In
California, the fungicide Fludioxonil (Scholar) is approved for use on pomegranates with a 5ppm maximum residue limit. The pomegranates have to be dipped in the fungicide solution because the fungal spores are usually in the calyx area of the fruit, which may not be adequately covered with spraying. Subsequently, surface moisture must be removed by an air flow to avoid having free moisture on the fruit in the box. Pomegranates are not hardy fruits as they may appear. They are as susceptible as apples to water loss and to physical damage by abrasions, impacts, compression, and vibration. Careful handling to minimize physical damage and avoiding chilling injury are very essential to keeping the quality of pomegranates. The recommended temperature is 7C and relative humidity between 90 and 95%. Pomegranates should be promptly cooled to 7C as soon as possible after harvest and should be kept at the recommended temperature and humidity during transportation and storage to reach their maximum postharvest-life of 2 to 4 months, depending on the cultivar. For more information, see the papers on pomegranates on our website (http://postharvest.ucdavis.edu), Publications/ Postharvest Publications Organized by Topic/ Pomegranates.
–Adel A. Kader