Divisi
Passion fruit brown spot
Alternaria passiflorae · Fungal
Photo: Forest and Kim Starr · CC BY 3.0 us
Brown spot is the most serious fungal disease of passion fruit. The fungus Alternaria passiflorae attacks the leaves, stems and fruit of the vine. Its spores are splashed up by rain and blown on the wind from old spotted leaves and fruit, and in warm, humid, wet weather they settle on wet foliage and start new spots within days. It strips the leaves that should be feeding the crop, rings and kills the fruiting shoots, and pits the fruit so it shrivels, drops early and cannot be sold.
Forest and Kim Starr · CC BY 3.0 us
Why it matters
Brown spot is the disease most likely to wreck a passion-fruit vine, and once it takes hold in warm, wet weather it can cost you up to 7 in every 10 fruit (70% of your crop). It hits you three ways at once: it kills the leaves that feed the plant so the whole vine weakens, it rings and kills the fruiting shoots so they die back and drop everything beyond the sore, and it pits the fruit so it wrinkles, falls early and cannot be sold. Worst of all, the vine lives on the same spot for 2–3 years, so the disease sits in the old spotted leaves and fruit on the ground and comes back at the crop again every wet season unless you keep on top of it.
When to act
start protecting the crop at the very first brown ring-marked spots on the leaves, stems or fruit — do not wait for more; and when warm, wet, humid weather is set to persist, protect the vine before any spots show
This guidance is general, compiled from published agronomic references including FAO and CABI. Thresholds and timing shift with your crop, your variety and the season.
In much of the region a spray is simply called mushonga — medicine. But a chemical group you cannot name is one you cannot rotate, and a product you did not write down has no pre-harvest interval you can observe. Mushonga, and other farming words →
The full passion fruit brown spot field guide
- Identify it
- Scout for it
- Control it
15 field-guide sections in the app
The full guide to passion fruit brown spot — every symptom to check, how and when to walk your field looking for it, and the controls that actually work, ranked. Built into your crop plan, so you are told to look before it costs you a harvest.
Crops it affects
Frequently asked questions
How do I identify passion fruit brown spot?
The first thing you see — on the leaves: small brown spots that start pinhead-size and grow into round-to-irregular brown patches, often with a paler tan centre and faint rings inside, like a target or an archery board. Each spot is usually ringed by a yellow halo where the green fades. As spots join up the leaf yellows and falls, and a badly hit vine loses much of its leaf.
When should I take action against passion fruit brown spot?
start protecting the crop at the very first brown ring-marked spots on the leaves, stems or fruit — do not wait for more; and when warm, wet, humid weather is set to persist, protect the vine before any spots show
How do I control passion fruit brown spot?
Prevent it first — grow an open, airy, dry canopy (your strongest non-spray tool): brown spot needs still, damp air and wet leaves. Give the vines their full wide spacing (about 3 big strides / 3 m in the row), train one clean stem up to the wire and clear all growth below it, and every couple of weeks pull out the tangled tendrils so the hanging fruiting shoots hang free like a loose curtain. Leaves that dry fast after rain get far less disease — this open canopy is the single most effective thing you can do without a sprayer.
Which crops does passion fruit brown spot affect?
Among the crops covered here: Passion fruit.
Catch it before it costs you a harvest
Divisi builds scouting into your crop plan — it tells you when to walk your field, what to look for at that stage, and what to do when you find it. Free for farmers, works offline.
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