VegNET Lockyer Valley Regional Update

Vegetable growers in South-East Queensland (SEQ) are facing a range of challenges as they navigate the complexities of pest management, disease control, and regulatory compliance. These
issues are not unique to the region; however, they have become more pronounced in recent seasons. With significant threats to crops, including onions, leafy vegetables, and the emergence of new pests like fall armyworm (FAW), it’s clear that collaboration, research, and effective management strategies are more important than ever.

The discussion panel Greg Teske, Shane Fitzgerald, Doris Blaesing and Neil Wilson and attendees at the Onion Workshop Gatton.

Onions under threat: the Stemphylium challenge

Onion production in Australia is dominated by South Australia (48 percent), Tasmania (22 percent), Queensland (12 percent), and other states making up smaller shares. In October and November 2024, onion growers, particularly in Queensland’s Lockyer and Fassifern Valleys, faced a significant threat from the fungal disease Stemphylium sp. This disease was largely unknown in Australia, which increased concern among growers. In response, a workshop was held in Gatton in December 2024, attracting over 40 participants from 14 different farming enterprises.

The threat posed by Stemphylium sp. has highlighted the need for urgent research. The disease shares similarities with other canopy pathogens affecting onions in the region, such as downy mildew and purple blotch, making early detection difficult. Misdiagnosis has been a recurring problem, with symptoms often being confused with other diseases. Effective diagnosis usually requires advanced techniques, such as microscope assays and pathogen culturing, but by the time symptoms become visible, it’s often too late for timely intervention.

Key discussions at the Gatton workshop, led by experts such as Neil Williams, Shane Fitzgerald, Greg Teske, and Doris Blaesing, focused on better disease identification, improved soil nutrition, and managing the impact of temperature on disease development. The importance of rapid disease diagnosis and research into Stemphylium sp. resistance to known chemistries was also emphasised, paving the way for future collaborative efforts to mitigate the disease’s spread.

Strengthening food safety in the leafy vegetable sector

Dr SP Singh visited SEQ in early December to speak at a working lunch in the Lockyer Valley, where he presented on the Safe Leafy Veg program, which aims to improve food safety systems within the vegetable industry.

His work emphasises the pathways of microbial contamination and the implementation of robust food safety measures, particularly in regions like the Lockyer Valley. During general discussion and question time at the working lunch, growers expressed concerns over the new legislation and lack of information from Queensland authorities. During his visit, Dr Singh also conducted farm visits with Granite Belt Growers, having in depth discussions on how growers could continue to meet compliance standards by addressing contamination risks in both the fields and packing sheds.

Managing insect pests: the growing threat of resistance

Insect pest management has long been a challenge for vegetable growers. The Lockyer Valley’s ongoing battle with diamondback moth (DBM) resistance began in the late 1980s, but by 2017, growers were noticing poor efficacy from chemical sprays targeting DBM. This prompted insecticide resistance testing, which confirmed that DBM had developed resistance to most IPM-compatible pesticides, except for Bacillus thuringiensis (Bts).

To tackle this growing issue, the industry developed an Integrated Resistance Management Strategy (IRMS), first launched in 2018. The strategy includes regular crop monitoring and a ‘traffic light’ system for pest management, helping growers make informed decisions about pesticide application. The introduction of new pests like fall armyworm has led to further adaptations in pest management strategies, with trials like Rapid AIM providing valuable data on pest behaviour and control efficacy.

Previous projects, such as the levy-funded VG16067 which studies the impact of pesticides on beneficial arthropods, and VG16062, which focuses on field and landscape management, are critical in supporting sustainable pest management practices. The success of these initiatives relies on timely information dissemination, with tools like text messages, emails, and social media helping keep growers informed about pest management updates. It is the aim of the Lockyer Valley growers and the VegNET RDO South-East to use the established network of agronomists and the Rapid AIM data to develop a mobile phone app to enhance the real time information available to growers and agronomists.

Figure 1. Daily fall armyworm pest pressure in the Lockyer Valley region

Looking ahead: collaboration and research at the forefront

As SEQ vegetable growers face mounting challenges in pest and disease management, collaboration, research, and timely communication will be key to navigating these obstacles. From workshops focused on the emerging threat of Stemphylium sp. to strategic discussions on food safety systems and pest resistance, the industry is working tirelessly to mitigate risks and ensure the sustainability of vegetable production.

With the introduction of new regulations, pest management strategies, and ongoing research projects, 2025 promises to be a year of adaptation and growth for the region’s vegetable industry. However, the success of these efforts will depend on continued cooperation among growers, industry experts, and researchers, all united in the shared goal of a more resilient and sustainable agricultural sector.

As the challenges persist, one thing is clear: the future of vegetable growing in South-East Queensland will rely on the collective strength of the community, working together to tackle pests, diseases, and compliance hurdles in a rapidly changing agricultural landscape.

FIND OUT MORE
Please contact Darren Brown on 0456 956 340 or email ido@lockyervalleygrowers.com.au