Robigalia Roundup LXXX: International Day of Plant Health

Hello {{first_name | Robigalia readers}},

Tomorrow is the International Day of Plant Health, observed on 12 May each year to raise global awareness of how protecting plant health underpins food security, biodiversity, and economic stability. This year's theme is "Plant Biosecurity for Food Security and Nutrition", recognising the essential role biosecurity plays in protecting crops from pests and diseases and supporting a zero-hunger world. For those of us working in the field, it's a chance to bring some of that work into public view.

Plant Health Australia has put together everything you need to mark the day, including posters, social media images, email banners, and digital meeting backgrounds. Whether you're planning something for your lab, your department, or just your own social feeds, the resources are free to use and worth sharing.

On that note, I'm excited to share that I recently sat down with Dr Jo Luck, Programme Director of the Plant Biosecurity Research Initiative (PBRI), for one of the most wide-ranging conversations I've had for this newsletter.

Jo's career spans molecular plant pathology, biosecurity capability building, science investment, and a great deal of thinking about the gap between researchers and the people who need their work most.

We talked about what it takes to communicate science effectively, why that gap still exists, and what it might cost us if we don't close it. The full interview will be with you in the coming weeks.

Now, onto this week’s edition:

Let’s dive in!

No plant pathogen has been simultaneously celebrated and cursed quite like Botrytis cinerea. The same organism that destroys strawberry harvests and collapses grape crops in wet seasons is, under drier conditions, responsible for the noble rot that concentrates sugars in Tokaji and Sauternes grapes into wines worth hundreds of dollars a bottle. This Jekyll-and-Hyde existence makes B. cinerea one of the most biologically fascinating pathogens in agriculture, and, with estimated global losses approaching $100 billion USD annually, one of the most economically consequential.

Botrytis cinerea (teleomorph: Botryotinia fuckeliana) is a necrotrophic ascomycete in the family Sclerotiniaceae, closely related to Sclerotinia sclerotiorum. Its genus name derives from the Latin for "grapes like ashes," a nod to the bunching of its grey conidiophores rather than any particular host preference. Unlike most of its Botrytis relatives, which are host-specific, B. cinerea is a generalist of extraordinary breadth.

The fungus survives between seasons as sclerotia or intact mycelia, germinating in spring to produce abundant wind-dispersed conidia. These spores are opportunists, entering through natural openings, wounds, and senescing tissue before triggering cell death in host tissue and colonising the resulting debris.

The host range exceeds 1,000 plant species, but the pathogen is particularly damaging on soft-tissue crops: strawberries, grapes, tomatoes, lettuce, roses, and numerous other horticultural crops. Grey mould presents as water-soaked lesions that rapidly become covered in the characteristic grey sporulating mass from which the disease takes its common name. On strawberries under wet conditions, more than 80% of flowers and fruit can be lost without fungicide intervention. The fungus is equally destructive post-harvest, continuing to rot fruit in storage, transport, and on supermarket shelves.

Botrytis cinerea is distributed across temperate and subtropical regions worldwide, making it a near-universal problem for fruit, vegetable, and ornamental growers. It thrives wherever cool temperatures coincide with high humidity, and its polycyclic disease cycle means that a single wet week during flowering can set off a season-defining epidemic.

The pathogen has developed resistance to virtually every major fungicide class introduced over the past 50 years, driven by its short life cycle, multinucleate conidia, and high genetic variability. Effective programmes combine timed fungicide applications at flowering (the critical window for primary infection), canopy management to reduce humidity, and increasingly, biological control agents. Several microbial biocontrol products are now registered, though none fully replace chemistry under high disease pressure. The resistance crisis has pushed researchers toward RNA interference, host resistance induction, and microbiome-based approaches.

Keep reading to meet Gideon Darko, a Master's student at the University of Cambridge whose bioprospecting work is screening UK yeast isolates for novel antimicrobial activity against B. cinerea.

This week, we meet Gideon Darko, a Master's student in Biological Sciences (Crop Science) at the University of Cambridge, where he is conducting his research in collaboration with NIAB, the National Institute of Agricultural Botany.

Gideon grew up in Ghana with a practical question at the centre of his thinking: how do you help farmers keep their crops alive? That concern for agricultural communities, and a conviction that plant pathology remains underappreciated as a discipline back home, shaped his decision to pursue the field. Alongside advancing his own research, he wants to show young agricultural scientists in Ghana that this is a field worth investing in.

He arrived at Cambridge with strong foundations already in place. Gideon completed a Bachelor's degree in Agriculture at Kwame Nkrumah University of Science and Technology (KNUST) with First-Class Honours before staying on as a Teaching and Research Assistant in the Department of Crop and Soil Sciences. That role deepened both his technical knowledge and his interest in biocontrol, and gave him early exposure to applied plant pathology research, including work on Bacillus subtilis as a biocontrol option against rot-causing pathogens in seed yams and studies on aflatoxin levels in tiger nuts sold in Ghanaian markets.

His current MPhil research takes a bioprospecting approach to biocontrol. Working with a collection of UK yeast strains, Gideon is screening for novel antimicrobial activity against a set of economically important fungal pathogens: Botrytis cinerea, which causes serious losses in grapes and soft fruit; Fusarium graminearum and Fusarium oxysporum, major threats to UK cereals and high-value vegetables respectively; and Verticillium dahliae. Promising yeast candidates have already emerged from the screen, with full characterisation to come.

For Gideon, the appeal of this work goes beyond the immediate pathogens. Finding effective biocontrol agents from biological sources contributes to building a bio-based economy, one that reduces dependence on synthetic chemistry and offers a more sustainable toolkit for managing crop disease.

He is a Mastercard Foundation Scholar, and beyond the laboratory serves as Project Lead for the AgriYouth Network, a youth-led organisation focused on farmer-centred training and bridging modern and traditional agricultural practice in Ghana.

You can find Gideon on LinkedIn and follow his work as his biocontrol research moves into the characterisation phase.

Have a job, scholarship, or event to advertise? List it in Robigalia. I’ll help promote your opportunity or event to a global network of over 10,000 plant pathologists for free.

See you next Monday!

P.S. Why Robigalia? The name originates from the Ancient Roman festival dedicated to crop protection. You can read all about the history here: