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Date released
09 February 2018

Thought to have originated between Mexico and Venezuela, the tasty sweet potato has now spread throughout the world, to become an important food in the Asia-Pacific region. In the highlands of Papua New Guinea, sweet potatoes provide 60 – 90 % of people’s energy requirements. It is an important staple in Timor-Leste and increasing in popularity in Australia and due to its health benefits; low glycaemic index and high beta-carotene levels. 80% of Australia’s sweet potatoes are grown in Queensland.

ACIAR has recognised the importance of the sweet potato in the Asia-Pacific region and funded a number of projects including the current ‘Supporting commercial sweet potato production and marketing in the PNG highlands’, run by Central Queensland University, to improve the productivity of this important staple.

Sweet potato planting material is not obtained from seeds but vegetatively from cuttings of vines growing from storage roots, or cut from vines in the field, therefore there is a high risk that planting material may be infected with viruses transferred by aphids or whitefly. These virus infections can cause plant yields to drop considerably. In fact the Australian sweet potato industry was able to increase yields from 30 tonne/hectare to 60 tonne/hectare, when it made Pathogen Tested (PT or ‘virus free’) planting material readily available to farmers. Having trialled PT material for a number of years, PNG is now also developing a PT or ‘Klin Sid’ program.

Dorcas Homare examines virus-free sweetpotato in the screen-house
Dorcas Homare examines virus-free sweetpotato in the screen-house
Winnie Maso in the tissue culture lab at Aiyura
Winnie Maso in the tissue culture lab at Aiyura
Myla Deros (left) and assistant Janet Lali inspect sweetpotato grafted to Ipomoea setosa
Myla Deros (left) and assistant Janet Lali inspect sweetpotato grafted to Ipomoea setosa
Agnes Jonah is training other women to grow PT sweetpotato
Agnes Jonah is training other women to grow PT sweetpotato
Agnes Jonah with PT sweetpotato in village screenhouse
Agnes Jonah with PT sweetpotato in village screenhouse
A box of PT sweet potatoes
A box of PT sweet potatoes

Equally important to producing PT planting material, is knowing what viruses are in-country and what biosecurity threats exist in the region. To assist in gaining knowledge of these threats and proactively reducing them, Queensland’s Department of Agriculture and Fisheries (DAF), a collaborating institute on the project, recently coordinated a workshop on Sweet potato production and PT technology. The workshop was designed to discuss and standardise;

  • the processes used in producing PT planting material
  • the current diagnostic technologies being used for sweet potato virus detection
  • managing PT planting material in a ‘seed scheme’
  • using PT planting material on-farm

The workshop was attended by research and development officers from DAF, National Agricultural Research Institute (NARI) PNG; Fresh Produce Development Agency (FPDA) PNG, ANU Enterprise, National Directorate for Quarantine and Biosecurity (DNQB) Timor-Leste Ministry of Agriculture and Fisheries, Northern Agriculture Quarantine Strategy and Aus Sweet potato Seed. It was also supported by Central Queensland University (CQU), University of Southern Queensland (USQ), Henderson RDE, Aus Sweet potato Seed and sweet potato farmers in Bundaberg and Rockhampton.

Participants posing for a photo at the end of the Sweet potato production and PT technology workshop
Participants posing for a photo at the end of the workshop

Sandra Dennien, Michael Hughes and Rachael Langenbaker, workshop coordinators, commented that it was excellent to see the very high levels of interest, enthusiasm, enjoyment of learning and openness to discussion the participants brought to the workshop. Participant Matt Kanua summed up his view of the workshop by saying, “Prior to the workshop, despite having used PT planting materials in a project, I did not fully appreciate the potential of it. However after this exposure I can fully see the impact it can have for our farmers”. Everyone mentioned that it was not only the scientific aspects of the course that were important, but that our collaborative research and development will definitely benefit from the commradery and professional relationships that evolved during the workshop.

Words courtesy of Michael Hughes, Farming Systems Officer at DAF.

Biosecurity
Plant viruses