Tuesday, 6 May 2014

Reaping benefits from postharvest science in the South Pacific

ACIAR Project leader Prof Steven Underhill describes how research in the South Pacific is being tailored to help boost Fiji fruit and vegetable exports

Through the ACIAR-funded Pacific Agribusiness Research for Development Initiative (PARDI), I have been fortunate to have the opportunity to work closely with many smallholder farmers in Fiji to assess their postharvest horticultural challenges and develop practical strategies to improve overall productivity. Paradoxically, while many Fijian farmers are seeking to increase exports, there has been very little attention spent on postharvest research in the region.

Prof Underhill at postharvest research trials in Fiji
As a postharvest specialist, part of my research through PARDI involves identifying why local farmers experience produce wastage and quality issues. The other part involves identifying how successful postharvest systems can be adapted to the South Pacific region so farmers can better participate in high-value markets and improve their livelihoods.

First impressions
My first impression of postharvest handling systems in the South Pacific was that of a sub-optimal system which lacks reliable infrastructure and technology. For example, packaging is inappropriate for transporting produce any distance (i.e. old boxes and sacks are used), packing facilities are limited, trucks overloaded with produce travel along rough roads, and refrigeration is non-existent.

Given these apparent postharvest limitations, improvements to postharvest practices present big opportunities to benefit local farmers. Historically, postharvest efforts have centered on introducing a concept of “postharvest best practice” from outside the region. Over the past decade, this approach has led to the construction of packing sheds and improved packaging with cool storage, and general postharvest training for farmer groups. However, I feel much more could still be done to tailor solutions to the local context and maximise benefits for smallholder farmers. 

Understanding local needs
In the current PARDI postharvest approach, we've invested time and effort into understanding why and how the existing postharvest handling systems operate before considering possible recommendations. Our goal is to really understand farmers, traders and vendors, the postharvest physiological consequence of the current handling systems, and ultimately where potential profit is lost and gained.

PARDI's postharvest research has focused on changing handling
practices, particularly with ripening tomatoes on-farm
We are very aware that the potential key research beneficiaries - smallholder farmers - are constrained by considerable livelihood disadvantages that have become endemic over time. There is little or no economic capacity for smallholder farmers to absorb mistakes, no matter how well meaning our intent. This time round we need to get it right.

Analysing postharvest supply chains
Over the last few years, along with researchers from Fiji National University and the University of the South Pacific, I have systematically analysed postharvest supply chains in the Sigatoka and Nausori regions. Our studies have looked at physical stresses and behavioural contributors that impact on overall product quality. 

We have been in the field weeks before harvest, monitored on-farm temperature and humidity conditions, assessed road conditions and transport driver behavior, undertaken numerous comparative municipal market studies, and measured market storage conditions and vendor quality grading process. Our team has used 3D mapping technology to spatially map in-carton bruising and product damage and compare different packing options for local environments. We are also currently using novel digital thermal imagery to monitor and refine on-farm ambient ripening practices (where fruit is picked and stored in available shelters on-farm to ripen). 

How it all works
Collectively, this research has provided detailed insight into how current postharvest supply chains function in Fiji. For instance, we now know that the peri-urban road infrastructure around Nausori is more likely to cause in-transit damage than the comparatively poor roads down the Sigatoka valley. Driver speed and smaller loads are the main culprits causing this damage, rather than the road quality. 
PARDI research has shown that eggplants are a comparatively
high-risk crop in terms of postharvest wastage

We know that on-farm ripening is one of the largest contributors to postharvest losses in tomatoes, and that the first few days of ripening are critical. We also know that okra, chilli and eggplant are comparatively high-risk crops in terms of producing relatively high levels of postharvest wastage. Conversely, small beans are far less susceptible to damage. 

While the common sight of overloaded trucks may be a prelude to high postharvest market wastage, we now know that in most municipal markets, daily wastage is actually a relatively low 2 to 4%. With 96% of product transported and on-sold by market vendors within 48 hours, the whole Fiji horticultural supply chain is one of fast-to-market and fast-to-sell.

Thinking through interventions
Like putting together the pieces of a large and complex jigsaw, this information is building a picture of a postharvest handling system that is relatively efficient but at the same time, very fragile. The answer to completing the puzzle is more about identifying how to improve current handling practices rather than changing infrastructure and technology. It is also about working with a complex, inter-connected supply chain that could break down if we introduce ill-considered postharvest chain interventions.

For instance, if we set out to change the stage of maturity of a commodity (e.g. how ripe tomatoes are), then in-transit damage is potentially altered. If produce is washed before packing, food safety risk may increase (depending on water quality). Likewise, if roads are improved and truck loading reduced, then subsequent increases in driver speed may cause greater product damage. If a central packing shed is used to grade and sort produce, this could potentially increase the risk of damage from multiple loading and re-loading of trucks. So, interventions need to be thoroughly thought through.
Tomato growers are reducing waste through better
postharvest handling

Achieving long-lasting impacts
What does this all mean in terms of PARDI’s influence? Is our project having a positive impact on postharvest practices? The short answer is ‘yes’!

Our approach is to present farmers with a range of practical options to empower them to make their own decisions about improving their handling practices. So far, our researchers have helped numerous groups of farmers come to appreciate the importance of postharvest handling. This has translated to tangible changes in handling practices, particularly with regard to ripening tomatoes on-farm. 

Collective problem-solving works wonders

Actively sharing information and working through alternative solutions with farmers is rewarding for all involved. We are finding this approach produces real and lasting results.

In the end, both sides learn something. Too often I think we tackle horticultural challenges by introducing answers to problems rather than collective problem solving. Engaging local smallholder farmers and their communities is the key to success.  

By Prof Steven Underhill, PARDI project leader (University of the Sunshine Coast)

More information:
PARDI web space – see under ‘Focus Areas’
YouTube clip on PARDI's postharvest work in Fiji
ACIAR's web page about PARDI


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