Clean seed system for commercial sweet potato production

Sweetpo tato is a major staple crop, particularly in the highlands of Papua New Guinea.
Other than growing it for household consumption, it is fast becoming a commercial crop that is transported to major towns to meet the growing urban demand.
Although this is positive for farmers, there is a growing concern that sweetpotato production is affected by a virus which is one of the main production constraint on sweetpotato in PNG.
Sweetpotato viruses are spread through sap-sucking insects from plant to plant and poor farm hygiene by farmers.
To provide farmers with healthy, clean planting material, a clean seed scheme called pathogen tested sweetpotato is now being promoted after noting the importance of this technology.
A series of laboratory and field processes is required prior to ensuring the planting material is clean and made available to growers.
In this ongoing effort to develop a ‘clean seed’ scheme, the Transformative Agriculture and Enterprise Development (TADEP) Program, through the Australian Centre for International Agricultural Research (ACIAR) is funding the
“Supporting commercial sweetpotato production in PNG Highlands” project in partnership with the National Agricultural Research Institute (NARI) and Fresh Produce Development Agency (FPDA). NARI is focused on the specific objective to increase the availability of clean planting material of sweetpotato, while FPDA takes lead to develop and strengthen marketoriented sweetpotato value chains and build the capacity of sweetpotato value chain players.
A workshop was facilitated in 2017, by the Department of Agriculture and Forestry, Queensland Australia, where seven professionals working with sweetpotato commercialisation in Papua New Guinea
and Australia met to enhance and advance their skills in aspects of sweetpotato pathogen testing process such as thermotherapy, virus removal/meristem extraction, and virus indexing of sweetpotato.
Technically, thermotherapy and meristem extraction using tissue culture is the first method aimed at getting rid of viruses that are present in sweetpotato plants.
After growing meristems into fully developed plants in tissue culture, pathogen testing procedures are undertaken.
Once the material tested is clean, volumes of clean disease free materials can be multiplied and supplied to sweetpotato growers.
Field and crop best-bet management practices are to be considered in order to maintain and provide growers with adequate clean materials.
The officers were also provided information which enhanced their knowledge in commercial production of PT sweetpotato planting material of the Queensland sweetpotato industry.
This is essentially the foundation of the clean seed scheme and the basis of commercial sweetpotato production for the near future.
An intensive theory and practical session into the PT scheme was covered during the two weeks training workshop.
This is mainly to enhance the pathogen testing skill capacity of the participants and provide an insight of procedures required to produce and manage clean diseasefree material.
The field component of the workshop allowed the participants to observe and hands on experience of the production of sweetpotato in the Australian commercial setting.
Two types of PT production groups were visited; the primary PT producer and the secondary PT growers.
At this stage, NARI has the skills and capacity to make available clean planting material. The tissue culture laboratory in Aiyura has been supplying PT planting materials of sweetpotato since 2010.
NARI and FPDA are better placed to support the commercial production of sweetpotato in PNG through relevant research and development Study reveals plight of coffeeprogrammes.