Date released
07 March 2024

This encouraging transition begins with clean virus-free planting material, or ‘klin kaukau’ as it is known locally, combined with an emerging entrepreneurial spirit among farming families in the country’s traditional sweetpotato growing regions.  

With higher yields, smallholders are moving from subsistence farming into semi-commercial and commercial enterprises.  

As well as having more sweetpotatoes to sell, the new, clean crops are better tasting than those produced from old planting material and are therefore in higher demand from consumers. New business opportunities have also opened to supply clean planting materials, to aggregate local harvests, and to value-add with semi-processed products such as sweetpotato flour. 

These are among the outcomes that are continuing to develop following a 5-year ACIAR-supported project on commercial sweetpotato production and marketing in the PNG highlands (HORT/2014/097). 

A virus-free beginning

Person holding up a test tube near a window
The National Agriculture Research Institute in Papua New Guinea holds sweetpotato tissue cultures and provides virus-free planting material for farmers. Photo: Conor Ashleigh

This project, which ran from 2016 to 2021, was underpinned by earlier ACIAR-supported projects to identify viruses affecting PNG crops and train local researchers how to eliminate viruses from plant material to produce the klin kaukau. 

The initial work in PNG arose from the experience of the Australian industry. About 20 years ago, Australian sweetpotato growers found that using virus-free planting material could double production and improve the appearance and quality of the vegetable. It saw the Australian industry take off. 

Based on this, ACIAR supported research to help PNG develop similar processes to produce its own virus-free planting material or klin kaukau.  

With support from Australia’s Department of Foreign Affairs and Trade, the project was scaled up to supply klin kaukau to smallholder farmers in the highland production areas.  

Project partners include Central Queensland University, the Queensland Department of Agriculture and Fisheries, and the Australian National University Enterprise, along with the PNG National Agriculture Research Institute (NARI), and Fresh Produce Development Agency (FPDA). 

Project leader Professor Phil Brown, Central Queensland University, describes klin kaukau as a new technology, or tool, for farmers. Field trials in PNG showed it could increase yields by up to 92% compared with crops grown from traditional planting materials. Klin kaukau crops also grow faster, maturing in 4 to 5 months, rather than 6 months, and produce sweetpotatoes with smoother skins and more flavour. 

And with higher-yielding crops comes the opportunity to develop commercial supply chains and markets, said Professor Brown. 

Farmers take the lead

The project identified a farmer in each of 14 different farming communities who was interested in commercial sweetpotato production and willing to take the lead in producing clean planting materials as the basis for new crops.  

The project used a farming family approach developed as part of another ACIAR-funded project, with both men and women acting in the lead, or early adopter, role on farms across 3 provinces: Western Highlands, Jiwaka and Eastern Highlands. 

To produce klin kaukau, the project provided each farm with screenhouses to keep out insect pests that can spread viruses. The farmers then used the klin kaukau to grow their own crops and supply it, for a nominal fee or free, to others in their communities. 

‘This enhanced the status of the lead farmers, some of whom then became aggregators of local production, connecting with markets,’ said Professor Brown. ‘Other farmers took advantage of business opportunities to sell klin kaukau outside their own communities, for example, to livestock producers in neighbouring regions who wanted to grow sweetpotato for stock feed.’ 

Over the course of the project, there was a 26% increase in the number of commercial sweetpotato farmers in the project area. The proportion of commercial farmers using klin kaukau rose from 16% to 90% in the project area. The supply of klin kaukau also spread from the provinces involved to 7 other provinces.  

As yields and income increased for farming families, families have reported using the additional income to improve housing, pay school fees, diversify their farming to include livestock, set-up irrigation systems and even to rent land to expand production. Lead farmers have also taken an active role in helping to train others to improve farming practices and further boost community production.  

A customer browses the market stall of a woman offering sweetpotatoes for sale.
Virus-free sweetpotatoes, known as ‘klin kaukau’ are in demand with customers for their better flavour. Photo: Central Queensland University

Market development

To support market development, Professor Brown explained that farmers received training from local development partners to develop entrepreneurial skills and help them understand the quality expectations for commercial markets, particularly for supermarkets in Port Moresby. 

‘For instance, farmers might need to grade their produce, and to package it in a way that reduces damage during transport. We also introduced growers to key players in some of the supermarket chains, and helped them establish supply contracts with supermarkets.’ 

Groups of women in each province also received training in simple processing and cooking opportunities to generate value-added products that can be sold in roadside and open markets. Following this, the Jiwaka Grassroots Association has taken the lead in developing sweetpotato flour as a new enterprise for its 100 farming family members. 

The project helped the association source 5-kg bags to package their flour in bulk, allowing the flour to be sold to bakeries, as well as being used for the baked goods that farming families produce and sell themselves. 

Association leader Ms Susan Kombangil said the project has put money in members’ pockets. 

‘We used to think that all we could do is work [for others] but now people like us in the village realise that we can … hold hands together (with organisations like ACIAR and FPDA) to improve and sustain our life into the future,’ said Ms Kombangil. 

A group of 24 people gathered together at the end of a field with rows of sweetpotato growing behind them.
Papua New Guinea farmers visit sweetpotato growers in Australia, learning about different farm practices. Photo: Central Queensland University

Staying virus free

Farmers with screenhouses can replace klin kaukau for propagation every 1 to 2 years to maintain quality of planting materials. Clean planting material comes from the NARI tissue culture facility at Aiyura in the Eastern Highlands. The facility maintains tissue culture and screenhouse samples of PNG’s main sweetpotato varieties.  

Ms Winnie Maso manages the NARI facility and liaises with the FPDA to supply clean plant material to farmers. The FPDA collects plant material from farmers for ‘cleaning’ at NARI where any viruses in the material plant are removed in a process that can take 18 months. The FPDA also redistributes certified clean material to farmers for propagation. NARI maintains clean planting material for 8 sweetpotato varieties, 6 of which were used in the ACIAR-supported project.  

Ms Maso said farmers have recently requested clean material for 2 additional varieties, one orange and one purple, in response to market demands and a growing emphasis on the nutritional values these varieties offer compared to traditional white and yellow varieties. 

ACIAR Program Manager, Horticulture, Irene Kernot noted that the project has provided many small successes that have contributed to a larger positive change. Among these, she highlights a trip for PNG farmers to Australia as part of the project, which gave them insights into different farming practices for sweetpotato production, such as irrigation, which have quickly been adopted on some farms.  

Some PNG farmers on the trip had never left their own communities. The trip helped them to meet not only Australian farmers but also farmers from neighbouring regions in PNG. This has allowed them to establish local farming networks to further the exchange of information and experiences across communities. 

The project has touched a lot of people. When we visit the communities involved in PNG to discuss the project, there could be 50 or 60 people taking part at each location. The pathogen-free crops are producing a better tasting product and there’s a lot of entrepreneurial thinking and activities happening, which is a real mark of success.

Irene Kernot,
ACIAR Program Manager, Horticulture

ACIAR Project ‘Supporting commercial sweetpotato production and marketing in the Papua New Guinea highlands’ HORT/2014/097.