MAINTAINING TABLE GRAPE QUALITY BY APPLYING QUARANTINE TREATMENTS DURING COOLING

Abstract

‘Red Globe’, ‘Thompson Seedless’ and ‘Crimson Seedless’ grapes were picked directly into ventilated polystyrene boxes and chilled for 6-8 h to approximately 20°C before being fumigated with 52.6 g m-3 ethyl formate + 21.6% carbon dioxide to treat external pests and stages likely to be found in harvested produce: 1st-3rd instar light brown apple moth and red back spiders; long-tailed mealy bug crawlers; adult two spotted spider mites, plague thrips and western flower thrips. Fumigation was applied for 2.5 h at 21°C in a refrigerated shipping container (68 m3) while cooling to 15°C. Cooling was continued to 1 and 2°C for 16 and 18 days, respectively to simulate control of Mediterranean and Queensland fruit flies. The results show that pests in harvested grapes can be killed and optimum fruit quality maintained in the cool chain.