Divisi
Passion fruit collar rot
Phytophthora nicotianae (with Fusarium solani) · Fungal
Photo: Eiku · CC BY-SA 4.0
Passion fruit collar rot is a soil-borne water mould — Phytophthora nicotianae, an oomycete (a fungus-like organism) — usually joined by the fungus Fusarium solani, that rots the vine at the collar (the stem-base at the soil line) and its roots. It thrives in warm, wet, poorly drained soil, spreading in splashing rain and surface water, and once the rot rings the stem all the way round there is no cure: the whole vine wilts and dies. The mould survives in the soil for years, so it keeps coming back on the same ground.
Eiku · CC BY-SA 4.0
Why it matters
Collar rot is the disease that kills passion-fruit vines outright — it does not just spot a few leaves, it rots clean through the trunk so a whole bearing vine wilts and dies in a matter of days. In a wet season on poorly drained land it can take most of a plot — up to 8 in every 10 vines (80% of your crop) — and because each vine feeds you for 2–3 years, a dead vine costs you years of fruit, not one harvest. Worst of all there is no cure once the collar is girdled, and the mould lives on in the soil for about 4 years, so the land itself turns against passion fruit. That is why the whole fight is in the prevention — good drainage, grafted vines and a dry collar — long before you ever see a sick plant.
When to act
the very first vine that wilts with a soft, brown, cracked stem-base — 1 sick vine is enough to act, because there is no cure once the collar is girdled; and drain, keep collars dry and protect the rest before symptoms whenever warm, wet weather and standing water set in
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 collar rot field guide
- Identify it
- Scout for it
- Control it
16 field-guide sections in the app
The full guide to passion fruit collar rot — 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 collar rot?
The first thing you see (above ground): a whole vine — or one big arm — suddenly wilts. The leaves droop, yellow and hang, and the vine looks thirsty even when the soil is wet. Over a few days to a couple of weeks the whole vine collapses and dies. On a vine you were already harvesting from, this sudden death for no clear reason is the classic warning.
When should I take action against passion fruit collar rot?
the very first vine that wilts with a soft, brown, cracked stem-base — 1 sick vine is enough to act, because there is no cure once the collar is girdled; and drain, keep collars dry and protect the rest before symptoms whenever warm, wet weather and standing water set in
How do I control passion fruit collar rot?
Prevent it first — plant grafted vines on a resistant root (your strongest tool): use grafted plants — a sweet purple top joined onto a hardy yellow passion-fruit rootstock that resists the collar and root rots — and keep the graft join a hand-span above the soil so the disease-prone top never grows its own roots. Start with clean, certified planting material, and never replant passion fruit on land where collar rot killed vines before — the mould stays in that soil about 4 years.
Which crops does passion fruit collar rot 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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