For farmer Nafetalai Makaui from Houma, improvements to Tonga’s watermelon export pathway have translated into practical changes on the ground. Working with Nishi Trading under a PHAMA Plus-supported fertigation pilot, he increased production on a one-acre plot from 8 tonnes to 21 tonnes, enough to fill a 20-foot shipping container.

“The watermelons are sweeter now because we’re keeping the soil consistently moist,” Makaui said. “Before, we relied on rain, and it just wasn’t consistent enough.”

The following season, however, wilt disease wiped out his entire crop after he replanted watermelons on the same land. Rather than stepping away, Nafetalai applied lessons from training on crop rotation, soil health and disease management. He has since rotated into other crops and plans to return to watermelon production using improved practices.

Nafetalai’s experience reflects both the risks faced by smallholders and the importance of stronger extension support, irrigation discipline and biosecurity awareness — not only for productivity, but for maintaining the integrity of Tonga’s export pathway.

Horticulture sits at the heart of Tonga’s economy, with more than half of all households engaged in farming. Across the country, watermelon exports provide a modest but strategically important source of seasonal income for rural households, supporting one of Tonga’s few consistently active fresh export pathways.

Tonga’s comparative advantage lies in its alignment with New Zealand’s winter supply window, when domestic production is low and prices are stronger. But this advantage also concentrates risk into a narrow export season, where disruptions can quickly erode returns and confidence.
In recent years, this volatility has been evident. Export volumes peaked before declining sharply following biosecurity detections and production constraints. These fluctuations highlighted the fragility of the export pathway and the need for more coordinated, system-wide responses.

At the centre of the challenge was not a single issue, but a set of interlinked constraints. These included inconsistent biosecurity practices, gaps in food safety and post-harvest handling, variable on-farm productivity, climate and water stress, and limited coordination between public and private actors.

The Pacific Horticultural Agriculture Market Access (PHAMA) and Pacific Horticultural Market Access Plus (PHAMA Plus) programs, funded by Australia and New Zealand, have worked alongside the Government of Tonga, exporters and research partners to address these constraints by strengthening the system.

Support from PHAMA and PHAMA Plus involved a coordinated package of interventions across the export pathway, with a strong focus on improving public-private coordination.
The establishment of, and support for, the Tonga Watermelon Export Taskforce has enabled joint planning, pre-season readiness checks and faster resolution of issues among regulators and exporters. Biosecurity systems have also been strengthened through improved diagnostics, updated procedures and targeted training.
Improvements in fumigation performance, hygiene, documentation and verification have helped align systems more closely with market requirements. At the post-harvest level, investments in packhouse upgrades, food safety systems and cold-chain readiness have improved consistency, extended shelf life and strengthened buyer confidence.

On farms, pilots in irrigation and fertigation, alongside improved pest and disease management, have demonstrated productivity gains and more efficient use of inputs.

Together, these changes represent a shift in how the sector operates. The export pathway is moving from reactive compliance to routine readiness, improving reliability within a narrow, high-risk export window.

The results are beginning to show. The pathway is becoming more coordinated and predictable, with clearer roles across government and industry, improved treatment verification and stronger packhouse performance. Losses are reducing, and exporters are better able to meet market expectations.

Importantly, these gains extend beyond watermelons. The systems, tools and practices developed through this work are designed to be transferable to other export-ready horticulture commodities, supporting broader sector development.

For farmers like Nafetalai, these changes are already tangible. His experience shows that while risks remain, farmers are better equipped to respond to them. At the same time, continued progress will depend on maintaining coordination and scaling proven practices.

Priorities include improving access to irrigation and inputs, supporting the transition from subsistence to more reliable market participation, and ensuring inclusive opportunities for women and young people across the value chain.

Tonga’s watermelon story is not simply about export volumes. It is about how a fragile pathway is being stabilised through stronger systems, clearer coordination and better alignment with market requirements.

As these changes continue to take hold, they are helping build the foundations for more resilient livelihoods and stronger export outcomes over time.