Divisi
Burrowing nematode
Radopholus similis · Nematode
Photo: Plant pests and diseases · CC0
Burrowing nematode (Radopholus similis) is a microscopic, thread-like worm that lives inside the roots and corm (the underground stem) of banana, plantain, citrus and black pepper. It burrows through the tissue, leaving reddish-brown lesions that girdle and rot the root system until the plant can no longer anchor or feed itself — the classic result is 'blackhead toppling disease', where plants fall over under wind or the weight of a filling bunch. It spreads mainly inside infected planting material (suckers and corms) and in soil carried on tools and boots, and once it is established in a field you cannot spray it out.
Scot Nelson · CC0 
Scot Nelson · CC0
Why it matters
You will never see this pest with your own eyes — it is a worm so small and thin it needs a microscope, and it lives hidden inside your banana roots and corm, eating away the root system that anchors and feeds the plant. A bad attack rots the roots so badly that the plant topples over, often just as the heavy bunch is filling — so you lose the whole bunch, up to 60% of your crop. Because it hides inside the roots and in the soil, no spray can reach it once it is established, and it rides into clean fields inside infected suckers. That is why clean planting material is your only real defence — once it is in your soil, you cannot get it back out.
When to act
toppling plants, poor anchorage or reddish root lesions found when checking roots
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 burrowing nematode field guide
- Identify it
- Scout for it
- Control it
14 field-guide sections in the app
The full guide to burrowing nematode — 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 burrowing nematode?
The first thing you notice is a plant leaning or toppling over. A big, healthy-looking plant — often one carrying a filling bunch — suddenly falls, its corm (the underground stem) twisting up out of the ground while the leaves are still green. Before that, plants are stunted, with smaller bunches that take longer to come. This falling-over is called 'blackhead toppling disease'.
When should I take action against burrowing nematode?
toppling plants, poor anchorage or reddish root lesions found when checking roots
How do I control burrowing nematode?
Prevent it — clean planting material is everything (your single strongest tool). Never take suckers from a field that has toppling or root-rot. Instead plant tissue-culture plants — clean plantlets grown in a laboratory and sold nematode-free — or, if you use suckers, pare the corm (peel off the outer skin and all the old roots down to clean white tissue) and dip it in hot water at about 50°C for around 15 minutes to kill the nematodes hiding inside before you plant.
Which crops does burrowing nematode affect?
Among the crops covered here: Banana & plantain.
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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