Fusarium
Changes in climate suitability for Fusarium are likely to create challenges and opportunities for cotton production.
Fusarium in NSW
The fungal pathogen Fusarium oxysporum f.sp. vasinfectum (hereafter referred to Fusarium) was first detected in NSW in the late 1990s. Fusarium is predominantly found around the Gwydir and Namoi valleys; however, it has been detected in all the cotton-growing valleys of NSW. These are shown on the accompanying map.
Fusarium is capable of persisting for years in the soil. Fusarium infects cotton seedlings through their roots. Once inside the plant, it restricts water and nutrient flow, leading to wilting and even plant death. Under conducive climatic conditions, the majority of infection occurs early in the season and progresses upwards through the plant during the remaining growing season.
This strain of Fusarium is specific to cotton, infecting all stages of crop growth, with the mortality of seedlings frequently greater than 50% and reduced yields, threatening the profitability and sustainability of the cotton industry.
What is the NSW DPIRD Climate Vulnerability Assessment? ⏷
Climate change is altering the biosecurity risks for many agricultural commodities across NSW. Primary producers need evidence-based information about the changing climate, and the risks and opportunities it may bring.
The NSW DPIRD Climate Vulnerability Assessments are enhancing the resilience of our primary industries by providing information and data to help the sector better plan for, and respond to, climate change. They have assessed climate change impacts for extensive livestock, broadacre and irrigated cropping, marine fisheries, forestry, horticulture and viticulture, and important biosecurity risks associated with these industries to inform sound planning, risk management and adaptation decisions.
How we assessed climate suitability ⏷
Climate projections were sourced from Climate Change in Australia’s ‘Application Ready Data’. This dataset is comprised of projections from an ensemble of 8 global climate models, each presenting a plausible future climate. Low confidence in the projected changes due to differences between the models is noted in the text. Care should be taken when interpreting these results.
The Climate Vulnerability Assessment is intended to highlight potential industry- or regional-level changes. Intermediate and high emissions scenarios were used in the assessments (RCP4.5 and RCP8.5), but these are not the only future scenarios possible. The inclusion of climate variables important to the commodities production was based on published research, expert knowledge and data quality and availability.
Climate suitability was assessed on a monthly timescale, with the reported climate suitability representing the average for a given month over all years in the dataset. This reflects the pattern of life stages for biosecurity risks and the need to determine which months are likely to pose the greatest risk to host commodities.
Learn more in the Climate Vulnerability Assessment Project Framework.
Climate impacts: expected challenges for primary industries
Overall, the likely impacts of Fusarium on cotton are projected to increase in spring and autumn but decrease in summer by 2050. These changes in climate suitability are likely to affect the cotton-growing valleys except the Murrumbidgee.
Changes to monthly climate suitability for Fusarium are likely to affect the cotton-growing valleys in different ways:
- Increased climate suitability for Fusarium is expected during September and May in the Macquarie and Lachlan cotton valleys under both emission scenarios (moderate to high confidence).
- Decreased climate suitability for Fusarium is expected from November to March for the Gwydir/Namoi and Macquarie cotton valleys under both emission scenarios. These changes are more prominent and wide-spread under the high emissions scenario (low to high confidence).
- Historical climate suitability is likely to be maintained in all regions during most of spring and autumn (low to high confidence). During winter, all sites will likely maintain historical levels of very low climate suitability (moderate to high confidence).
The effects of Fusarium on the cotton industry in NSW will depend on:
- the future distribution of cotton production in NSW,
- changes in production timings, and
- the overlap between susceptible life stages of cotton and the lifecycle of Fusarium.
A warmer climate could increase climate suitability for Fusarium in NSW by 2050, affecting the cotton industry. Due to rising temperatures, the Macquarie and Lachlan cotton valleys may experience higher infection rates in spring and autumn, leading to possible earlier infection at planting and improved post-harvest survival of the pathogen on stubble.
Decreased climate suitability for Fusarium during the warmer summer months in the Gwydir/Namoi valleys could result in reduced mid to late-season infection, a potential opportunity for this region in the future. Current strategies for managing Fusarium are likely to remain effective but may need adjustments to adapt to these changes. Suggested modifications include selecting high F-rank varieties, managing stubble by leaving it on the surface for a more extended period after harvest, and placing greater emphasis on controlling host weeds to minimise the risk of infection. To support these cotton regions, research needs to be undertaken to assess these management approaches and communicate effective management strategies to industry.
Where can I find the climate suitability maps?
Maps of historical and future climate suitability for commodities and biosecurity risks were produced to demonstrate where in the state they are likely to thrive or else be limited by future climatic conditions. The maps are provided in the Fusarium Results Report (PDF, 4809.5 KB).
Fusarium Factsheet
(PDF, 1985.53 KB)
Fusarium Results Report
(PDF, 4809.5 KB)
