In partnership with VegNET 3.0 and the Lockyer Valley Growers Association, AUSVEG hosted an insightful event in early December 2024 at the Gatton Research Centre in the Lockyer Valley, bringing together growers, researchers, and industry experts to tackle current challenges and pressures in the onion industry.

This event served as a knowledge-sharing platform and featured expert presentations, interactive panel discussions and a barbeque dinner to finish. Participants explored strategies to improve soil health, combat disease, and enhance storage outcomes.

Local organisations and experts provided practical solutions tailored to the local growing conditions, with interstate speakers providing alternative experiences and new perspectives. The event highlighted the importance of innovation and collaboration within the industry to ensure longevity and sustainability of the onion industry.

The event addressed topics identified as priorities by the region, such as soil health, improved onion storage outcomes, disease management, and benchmarking for improved farm profitability.

Dr Doris Blaesing from RMCG and Dr Neil Wilson from Metagen spoke on the relationship between soil health, crop nutrition, and storage quality in onions.

“A healthy soil promotes optimal nutrient availability and plant growth, which directly influences onion quality, including its ability to hold up under storage conditions,” Dr Blaesing emphasised.

Key soil properties, including structure, drainage, pH balance, and organic matter, ensure optimal nutrient uptake and minimise risks such as uneven growth and storage diseases, she told attendees at the workshop. Proper biological activity in the soil, such as the presence of beneficial microbes, further enhances nutrient cycling and pathogen suppression, contributing to the durability and quality of stored onions.

Balanced crop nutrition is equally vital, Dr Blaesing said. Adequate levels of nitrogen, phosphorus, potassium, sulphur, calcium, and micronutrients strengthen bulb firmness, disease resistance, and skin quality while minimising sprouting during storage.

Practices such as nutrient budgeting, timely irrigation, and post-harvest handling, including curing bulbs, enhance storage outcomes. Together, these integrated management strategies ensure that onions maintain their quality from harvest to storage.

Phil Frost from Arvensis research spoke on the progress of the Hort Innovation onion levy-funded project Optimising chemical and cultural control of onion white rot.

“80 percent of land sown to onions annually is infected with white rot, with crop losses of 10-30 percent attributed to the disease,” Phil stated.

Phil highlighted both cultural and chemical management strategies that can be implemented to control or suppress white rot. Biological control agents can compete with and inhibit white rot fungus when applied as granular treatments early in the season. However, relying solely on biological controls may not be sufficient, he told attendees, and an integrated management approach paired with best-practice biosecurity on-farm is important to mitigate the spread of disease.

Key strategies used in the management of white rot on-farm include regular soil testing to detect white rot presence, applying germination stimulants pre-planting to reduce viable sclerotia in
the soil, using new fungicide modes of action and rotating chemistry to prevent resistance, and enhancing soil health to improve plant resilience.

Attendees heard from Dr Neil Wilson and Shane Fitzgerald from Metagen on management and diagnosis of Stemphylium leaf blight in onions, with Elders Agronomist Greg Teske providing attendees an on-the-ground local perspective of the disease in the region.

Stemphylium leaf blight, caused by Stemphylium vesicarium, is a fungal disease primarily affecting onions along with a number of host crops such as garlic, brassicas, pears and spinach.

Stemphylium is characterised by yellow spots on leaves that expand into tan or brown lesions, leading to leaf dieback and reduced yield. The fungus spreads through wind, rain, and contaminated tools, surviving in plant debris and soil over winter.

Favourable conditions for disease development include warm overnight temperatures, high humidity, and poor irrigation or nutritional practices. Early detection of symptoms, such as necrosis at leaf tips, water-soaked lesions and leaf spot, is crucial for management, as severe infections can result in premature plant death and failure to lodge normally.

Effective management strategies include crop rotation with non-host species for at least two-three years, maintaining farm hygiene by removing infected plant residues, and applying fungicides preventatively or at the first sign of symptoms. Balanced nutrition, particularly avoiding excess nitrogen, and proper irrigation practices, such as early morning watering to allow leaves to dry quickly, further mitigate disease risk.

Resistant onion varieties and regular scouting to detect the disease early also supports effective management. Fungicide rotation and adherence to resistance management plans are vital for sustainable disease control.

Lauren Jones from RMCG delivered an informative presentation on the Level Up Hort benchmarking project. Level up Hort is a levy-funded program focused on supporting both vegetable and onion businesses to increase profitability and build long-term resilience, by providing clear and effective measures of success.

Lauren shared that the project’s report on the 2023 season found that Australia’s more profitable vegetable and onion growers were spending more on inputs, but were better at converting costs to income.

The Level Up Hort program can be broken down into three components, she said; link, learn, leverage. Firstly, once signed up to the program, independent and highly qualified farm business consultants are linked with growers for detailed data collection. An in-depth analysis and high-level review is conducted to establish which factors on-farm affect production efficiencies, what drives profit in your particular business and how to best grow your assets.

Secondly, a face-to-face consultation reviewing and learning from the data previously identified will aid the farming business in making data-driven management decisions, aiding to create a more efficient and profitable business that can better cope with challenging seasons and unpredictability in the market.

Lastly, knowing your costs and how best to distribute your resources within your business allows you to control and influence the factors that turn small returns into greater returns and grow your business wealth over time, therefore helping to leverage your business.

Thank you to all collaborators, speakers and attendees who contributed to the success of the Lockyer Valley event. For updates on future onion events and project outputs, stay connected through AUSVEG’s communication channels.