More integrated evaluation of cold chain performance is key for developing a more resourceefficient, energy-smart food supply chain. The present study applies this rationale to evaluate the ambient loading protocol for overseas export of citrus fruit in refrigerated containers. Ambient loading implies that fruit, packed into ventilated boxes, are directly precooled in the container. This technique provides several economic and logistical advantages but is particularly challenging for phytosanitary cold disinfestation treatments. For such an integral approach, multiple relevant product and process parameters were monitored throughout the cold chain, such as fruit cooling rate, quality parameters, shelf life, pest disinfestation efficacy, and their spatial uniformity throughout the cargo load. Also energy consumption of the refrigeration unit was measured. The performance of the standard ambient loading practice was compared to two novel airflow strategies: the channelling configuration, which reduced airflow bypass between pallets, and the horizontal configuration, which forced air horizontally through the pallets. Standard ambient loading was able to cool the produce within about 3 d to the seven-eighths cooling time. The channelling configuration exhibited similar cooling behaviour but the fruit lost less moisture, lasted longer in shelf life conditions and had a better quality. The horizontal configuration performed worse on all aspects. The cooling performance of the container clearly depended on the way in which it was stowed and convectively cooled. This more holistic evaluation of the cooling strategy unveiled several trade-offs and allowed a multi-parameter evaluation of technological improvements to cold chain practices.

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The citrus mealybug, Planococcus citri, is a highly destructive pest of citrus, occurring only in the aerial parts of plants. Humidity will be one of the key factors to consider when using entomopathogenic nematodes (EPN) as biological control agents. Different adjuvants can be added to suspensions of EPNs, to improve control as a foliar application. An aqueous suspension containing Heterorhabditis zealandica and 0.3% Zeba w significantly increased P. citri mortality by 22% at 80% relative humidity (RH) with a temperature cycle starting at 228C for 14 h and 118C for 11 h. The same polymer formulation was tested for Steinernema yirgalemense and mortality of P. citri increased by 21% at 60% RH and by 27% at 80% RH. The addition of Nu-Film-P w and Zeba w to H. zealandica suspensions did not significantly retard application run-off on citrus leaves. The combination of Nu-Film-P w and Zeba w , however, was able to significantly retard sedimentation, increasing the average number of nematodes deposited on 2-cm 2 leaf discs by 10 nematodes. In an aqueous suspension, nematodes settle rapidly to the bottom, resulting in an uneven distribution of nematodes. Xanthan gum, at a concentration of 0.2%, was highly effective at retarding sedimentation, with 72% of the initial nematode number still in suspension after 1 h. Zeba w , at a concentration of 0.3%, despite not being as effective as Xanthan gum, nevertheless still retarded sedimentation significantly. This is the first report of the potential of Nu-Film-P w and Zeba w to improve EPN performance against P. citri when used above ground in citrus orchards.

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