02/06/2026
Alternaria Brown Spot (ABS) remains one of the most challenging and economically damaging diseases in susceptible citrus cultivars.
In this CRI Podcast discussion, Prof Jacquie van der Waals, Researcher and Programme Coordinator: Preharvest Diseases, unpacks new CRI research aimed at helping growers manage ABS more effectively through improved cultivar screening and smarter disease prediction tools.
The discussion explores:
• why ABS can severely impact export quality and packouts
• CRI’s work on identifying resistant and susceptible cultivars earlier
• the development of reliable inoculation and genetic screening methods
• how the CRI ABS infection risk model helps growers optimise spray timing
• why preventative disease management is critical
A key message from the episode is that by the time visible symptoms appear, infection has already taken place. This makes proactive management and accurate infection risk prediction essential for effective control.
The discussion also highlights how better timing of fungicide applications could help growers reduce unnecessary sprays while still maintaining protection during high-risk infection periods.
🎧 Watch or listen to the full conversation on the CRI YouTube channel: https://youtu.be/0wn3wGbl5pE or Spotify: https://open.spotify.com/episode/2nEAS2yDYoMBj2vBMD5obK?si=6-t8Nrq8TLaxYEwMwY1LXQ
For viewers wanting additional background on Alternaria management and disease risk in citrus, CRI also recommends watching the previous CRI Podcast discussion with Prof Jacquie van der Waals on this topic: https://youtu.be/Kt5P1gV6Kzc