Divisi
Pineapple base rot
Thielaviopsis paradoxa (Chalara paradoxa) · Fungal
Photo: Hawaii. Board of Commissioners of Agriculture and Forestry · No restrictions
Pineapple base rot (also called butt rot or black rot) is a fungal disease caused by Thielaviopsis paradoxa. It is a wound rot: the fungus cannot break into a healthy, unbroken plant, but the moment you cut a sucker, slip or crown from the mother plant it can slip into the fresh, wet wound at the base. In warm, damp conditions it turns the cut base soft, watery and black, so the shoot never roots and simply rots away in the ground. Its spores live on in old pineapple trash and in the soil, waiting for the next fresh cut — and the same fungus rots bruised or cut fruit into a soft, dark 'water blister' after harvest.
Why it matters
Base rot strikes at the most expensive moment of the whole crop — the shoots you have just cut, carried and planted. Because it only needs a fresh wound and a little warm damp, a careless batch of uncured setts piled in the shade or pushed into wet soil can rot at the base and fail to root — up to half of them (50%) lost before the crop even starts. Every rotted sett is a gap in your block that you cannot fill in later, so the stand you lose now caps your harvest for the whole two-year crop. The good news is that this is one of the most preventable diseases you have: a healed, dry base and well-drained soil stop it almost completely.
When to act
pull and replace any newly-set shoot with a soft, blackening base that has not rooted; if more than about 1 in 10 setts (10%) are rotting at the base, stop planting from that batch, improve curing and drainage, and dip the bases before setting any more
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 pineapple base rot field guide
- Identify it
- Scout for it
- Control it
16 field-guide sections in the app
The full guide to pineapple base 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 pineapple base rot?
The first thing you see: newly planted shoots that sit still and never root while their neighbours take. Pull one gently and the base comes away soft — the firm, pale cut has turned into a wet, watery, blackening rot.
When should I take action against pineapple base rot?
pull and replace any newly-set shoot with a soft, blackening base that has not rooted; if more than about 1 in 10 setts (10%) are rotting at the base, stop planting from that batch, improve curing and drainage, and dip the bases before setting any more
How do I control pineapple base rot?
Prevent it first — cure the setts (your single strongest tool): after cutting suckers, slips or crowns, strip a few of the lowest leaves and lay them in the shade, base upward, for several days up to two weeks, until the cut base dries hard and heals over. 'Curing' just means letting the wound scab shut — a healed, dry base leaves the fungus no wet wound to get in through. Never plant a fresh, wet-cut sett straight into the ground.
Which crops does pineapple base rot affect?
Among the crops covered here: Pineapple.
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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