Mandarins. Export quality satsumas need careful handling.
Beever, D. J.;
Orchardist of New Zealand Year: 1990 Vol: 63 Issue: 2 Pages: 24-25 Ref: 2 ref.
1990
บทคัดย่อ
Fruits of the Japanese satsuma cultivar Miyagawa were stored, enclosed in a plastic polyliner in single layer trays, for 7 weeks at 0, 5 or 10 deg C. They were then transferred to 20 deg for a further 2 weeks for shelf-life evaluation. Fruits were mature, although the skins were still partly green, when they were placed in storage. At the end of the cool storage period those at 10 deg were fully coloured, those at 5 deg had lost much of their green coloration but those at 0 deg remained green. The remnant of the stem (button) had fallen or was easily detached from fruits stored at 10 deg ; the incidence of stem end rot (Phomopsis citri) [Diaporthe citri] was higher at this time than in fruits stored at lower temperatures. After a further week at 20 deg there was considerable rot development; those fruits previously stored at 0 deg were the worst affected and chilling injury to the skin was evident. The colour differences related to cool storage temperatures persisted. In subsequent trials, fruits of the cultivars Miho, Okitsu, Matsuyama stored at 5 deg C for 6 weeks followed by 2 weeks at 20 deg showed some weight loss but quality at the end of the period was quite satisfactory. In another study, Miyagawa fruits were stored with or without waxing either boxed or enclosed in a plastic polyliner for 6 weeks at 5 deg followed by 2 weeks at 20 deg . In some cases 2,4-D at 500 p.p.m. was included in the wax coating. A postharvest dip of imazalil or benomyl was applied to some fruits in each treatment. Fruits held in a polyliner showed least weight loss and the best appearance. Waxing did not influence the rate of water loss. When 2,4-D was included in the wax, button retention was improved and this treatment should provide some protection against stem end rot. A postharvest dip in fungicide greatly reduced the incidence of decay (mainly Penicillium, Geotrichum and Alternaria spp.). Changes in the sugar:acid ratio which might occur during transit were investigated in Miyagawa fruits collected from sequential harvests and stored at 5 deg for 6 weeks followed by 17 days at 20 deg . Data on % juice, % soluble solids, % titratable acids and the soluble solids:titratable acids ratio are tabulated. In general, changes in sugar levels and % juice were not significant but there was a fall in titratable acidity with time. Such loss of acidity would eventually lead to an insipid, flat taste. Recommendations are given on postharvest treatment of Japanese satsumas for export by sea.