Investigating soil pH and nutrition as possible factors influencing pink rot in potatoes – a pilot study (PT19000)
What’s it all about?
This project is investigating how soil pH and nutrition may play a part in reducing the impact of pink rot disease in potatoes. By furthering the industry’s knowledge on this soilborne disease, the work will provide direction for future research priorities and recommendations on how to best manage pink rot.
Specifically, the project will:
- Perform a literature review of recent related pink rot research work
- Survey growers and agronomists on their experience and view of pink rot
- Conduct pot trials to study the role of PH, calcium, other nutrients and acidifying fertilisers on pathogen load and pink rot expression
- Establish field surveys of 20 potato paddocks known to have a recent history of pink rot to assess disease factors and analyse the soil.
Over the last four months, the Year 2 field trials and surveys have been set up at 9 trial sites in north-east Tasmania with four periodic soil/crop assessments occurring through to February 2022.
The Year 2 pot trials have been planned and will incorporate one treatment pathogen level across two soil types with N form and Ca amendment treatments tested.
Informal discussion with growers and industry has also provided insight into historical issues related to pink rot and identified areas for further work.
A draft literature review has been prepared with a focus on:
- Soil conditions, in particular pH and soil properties, from key potato growing regions in Australia
- Background of the pink rot pathogen and key factors impacting disease expression.
Plans for Year 1 pot trials to assess the impact of calcium levels with and without pH adjustment were completed, in preparation for planting in January-February 2021. Field soils of ferrosol and a sandy loam were collected, with pink rot pathogen isolates (P. erythroseptica) being bulked for addition to the pots.
The year 1 field survey commenced, with soil samples for PreDicta Pt and basic soil chemistry collected from 11 different sites in four distinct regions of Tasmania (Sisters Creek, Devonport, Scottsdale, Epping Forest). Six of the field sites also include research strips of calcium amendments, added either pre-spread, in-furrow and / or surface spray. Planting was from late October through to early December, with planning and site selection aided by field officers and industry.
The team considered historical analysis by speaking with researchers about prior pink rot work and any useful information available from recent trials. Input was also sought from industry about the perception of pink rot disease management in terms of landscape influence, irrigation management and calcium usage. This information will be further analysed over the coming months.