According to the International Standards for Phytosanitary Measures, a systems approach is “the integration of different risk management measures, at least two of which act independently, and which cumulatively achieve the appropriate level of protection against regulated pests.” (ISPM5). Therefore, instead of relying on a single treatment such as post-harvest cold storage or fumigation, a systems approach can consider the whole horticultural production and export system.
ISPM14 (The use of integrated measures in a systems approach for pest risk management) and ISPM35 (Systems approach for pest risk management of fruit flies (Tephritidae) ) detail a wide range of factors that might be considered such as the prevalence of the pest, the susceptibility of certain fruits or varieties of fruit to infestation, the effect of in-field control practices, whether fruit are susceptible at a certain point of maturity, the impact of fruit grading and processing, how fruit is stored, and where fruit is exported to.
A more flexible approach to biosecurity…
A potential criticism of single point biosecurity treatments is that they dont give much consideration to the fact that commercially produced and traded fruit are likely to be high quality and substantially free of pests. The result is that the treatment applied needs to be able to deal with a potentially large number of pests which in turn requires stringent treatments supported by large and expensive trials.
Systems approaches can balance this by explicitly considering the cumulative effect of pest monitoring programs, good in-field management, grading in the packinghouse and other steps that are either part of good agricultural practice or an extension of the same. If supported by good monitoring and verification processes, it may be possible to demonstrate that the chance of exported being fruit is acceptably low without substantially increasing the cost of production.
Take for example cherries grown in inland regions of Australia around towns such as Young, NSW. In these areas the low temperatures that are needed to promote a good crop also delay fruit fly activity. In practice, fruit flies are not active or laying eggs until the cherry harvest is well underway or even nearing completion. Therefore, the risk posed by fruit flies is already low. In addition, growers can apply protein bait sprays and other control measures, and remove damaged and unsightly fruit in the packinghouse. If coupled with steps that verify the very low or even negligible incidence of fruit flies, this might be sufficient to satisfy an importing market.
… monitored at multiple steps
Compared with single point treatments, the development, assessment and approval of a systems approach for managing fruit flies may be a more involved process. This is because it relies on a greater understanding of how fruit flies can be managed at multiple points along the production pathway. The operation of a systems approach may also require a number of monitoring and assurance steps in-field and in the packinghouse. However, commerical producers who already operate under HACCP principles or have certification under SQF2000 or from a major reatiler are already familiar with the processes.
Whether the benefits of a systems approach outweigh the costs and possible complexity will depend on the crop and target market. For commodities that handle cold treatment well and shipped by sea, the simplicity of in-transit cold treatment may be the preferred option.In contrast, when there is a short time to market the flexibility of systems approach may be the best option.
Some examples of systems approaches
Queensland table grapes – ICA-20
Table grapes are recognised as a poor host for fruit flies. Combined with effective in-field control practices, demonstration of the effect of culling during packing, and supported by post-harvest inspection, the acceptable low risk posed by Queensland fruit fly led to the development of ICA-20 (Interstate Certification Assurance procedure for domestic trade).
Managing the risk of citrus fruit in Texas during a Mexican fruit fly outbreak
While the US is officially free from Mexican fruit fly, outbreak are occasionally declared in commercial areas adjacent to residential areas. A risk based approach to managing the movement of citrus within the US was approved in late 2015. The approach includes a range of in-field management including SIT and bait sprays and the exclusion of exports from within the outbreak centre to certain citrus producing states. However, citrus groves more than 250m from the outbreak centre are able to ship fruit. The risk assessment includes quantitative assessment of the risk posed by fruit flies.