Citrus developments bearing fruit in Tonga and Samoa

Harvests from newly developed orchards in Tonga are raising hopes for increased access to locally grown citrus fruit. Lemons, limes, sweet oranges and mandarins are all well known on the islands, but imported fruit has grown to dominate local markets in recent decades.

However, harvests from new orchards established 5 years ago under an ACIAR-supported project mark an anticipated revival of local fresh fruit production. Mandarins in particular have sold quickly, fetching good prices this year.

An initial ACIAR-supported project investigated tropical fruit crops in Fiji, Tonga and Samoa. Although that project ended in 2020, it identified citrus as an important fruit crop for development in Tonga and Samoa. Horticultural expert Professor Steven Underhill at the University of the Sunshine Coast led this work and now also leads Phase 2, which will run until 2025, and is focused solely on citrus.

Professor Underhill said citrus has a comparatively long shelf life and a winter harvest provides an off-season fruit supply. They are also a diabetic-friendly fruit, which is important as almost one in 3 adults in Tonga and Samoa is estimated to suffer from diabetes. This fits with one of the project’s objectives: to get people to eat more fresh fruit.

Health and business goals

ACIAR Research Program Manager, Horticulture, Irene Kernot said increasing the availability of affordable fresh fruit could help to increase consumption and improve diets.

From an agribusiness perspective, Ms Kernot said investing in improved tree genetics, along with propagation and crop management skills will also support new business opportunities for smallholders in Tonga.

As part of the original ACIAR project, more than 1,000 citrus trees were planted in 5 orchards. Varieties trialled include Washington and Valencia oranges; Emperor, Imperial, Afourer and Ellendale mandarins; Meyer lemon and Tahitian lime.

Elite Australian rootstock with advanced disease resistance and vigour, plus early and late season varieties, have the potential to extend local production from 4–6 weeks to 6 months.

In Tonga, 3 orchards are based on the outer island of Eua. One is a private orchard and 2 are community-run. There are also a further 2 commercial orchards on the main island of Tongatapu. One is owned by the NGO Mainstreaming of Rural Development Innovation (MORDI) Tonga Trust, the other by fruit export enterprise Nishi Trading.

Nishi Trading Managing Director Mr Minoru Nishi said the ACIAR-supported research has helped to find species well suited to the climate in Tonga. His company was the first to harvest and sell crops from trees established as part of this work. He supports the production of more fresh, high-quality fruit for local consumers to replace imports.

‘It will help increase incomes for people involved in fruit tree production and fruit retailing. By building local skills and capacity, it is also helping to improve employment opportunities,’ said Mr Nishi.

Two people collecting citrus fruit and packing in a basket — Smallholders in Samoa collect citrus for sale and for development of new products. Photo: University of the Sunshine Coast

Skills development

The project is also building local capacity and skills in tree propagation and grafting, pruning and orchard management, including the staff at MORDI.

‘They are now running a highly successful plant nursery,’ said Professor Underhill. ‘The relationship with MORDI has also been essential in developing the community orchards on Eua, and also in providing training to local farmers in propagation and orchard management.’

Demand for the fruit produced to date has been strong and Professor Underhill said surveys will be conducted to determine consumer preferences for different varieties, particularly of oranges and mandarins, as well as barriers to increased fruit consumption.

People surrounding and watching a citrus tree being planted — Citrus propagation and management in Tonga are being led by ACIAR project partner, MORDI. Photo: University of the Sunshine Coast

Samoan trials

In Samoa, there is an existing small-scale citrus industry on the island of Savai’i with native citrus trees that are well adapted to local conditions. A trial is underway to compare local seed-produced trees with imported elite grafted material.

An important core focus of the project’s work in Samoa is enabling citrus value-adding opportunities. The local citrus harvest includes limes, oranges and grapefruit but it is a short season, which causes a supply glut and low prices.

According to the Samoan project coordinator Dr Seeseei Molimau-Samasoni at the Scientific Research Organisation of Samoa (SROS), preliminary discussions between SROS and citrus farmers revealed a keen interest in value-adding, with farmers eager to make full use of the local citrus supply, particularly during peak season.

Fiji-based food scientist Dr Richard Beyer has been leading this work as part of the project. At a product development workshop on Savai’i in April 2023, he introduced community members to food safety and handling procedures, and to a range of products and preserving processes that they might try.

‘There was “explosive enthusiasm” from the women attending,’ said Dr Beyer.

Workshop experiments created 8 new products using citrus ingredients, and 4 other products to supplement production during the citrus off-season, with half showing promise for further development.

The women have since formed a group to develop new food products and business opportunities. Products include an orange syrup that is proving popular on Samoa’s traditional pancake breakfasts, a fruit juice cordial, citrus confectionary and chillies pickled in lime juice.

With the right products and packaging, Dr Beyer said these products have the potential to generate new business opportunities, tapping into tourist markets as well as local demand.

ACIAR PROJECT: ‘Enhanced fruit systems for Tonga and Samoa (Phase 2): community-based citrus production Tonga, Samoa’ (HORT/2019/165); ‘Enhanced fruit production and/ postharvest handling systems for Fiji, Samoa, and Tonga’ (HORT/2014/077).