Divisi
Sweet potato virus disease
Sweet potato feathery mottle virus and Sweet potato chlorotic stunt virus · Viral
Photo: JIRCAS (Nakano Masaaki) · CC BY 2.0
Sweet potato virus disease is the severe illness that strikes when two viruses meet in the same plant: one spread by aphids (Sweet potato feathery mottle virus) and one spread by whiteflies (Sweet potato chlorotic stunt virus). Alone each does little harm, but together they cripple the plant. Both hide inside vine cuttings, so the disease travels mostly in the planting material you carry from field to field, then spreads further as tiny insects move it plant to plant.
JIRCAS (Nakano Masaaki) · CC BY 2.0
Why it matters
Sweet potato virus disease can wipe out up to 80% of your roots — turning a full harvest into a handful of small, stringy tubers not worth digging. It is dangerous because it hides inside the vines: an infected cutting looks healthy when you plant it, so you can spread the disease across your whole field without knowing. And once a plant is sick there is no cure and no spray that heals it — the virus lives in every part of the plant. Your only real weapons are clean planting material and pulling out sick plants early, before insects carry it further.
When to act
Rogue symptomatic plants as soon as they appear and control vectors; never take cuttings from a symptomatic mother plant.
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 sweet potato virus disease field guide
- Identify it
- Scout for it
- Control it
17 field-guide sections in the app
The full guide to sweet potato virus disease — 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 sweet potato virus disease?
The first thing you see: plants that just sit there and stay small and stunted while the healthy ones around them run and cover the ground. A sick plant looks weak and never fills out.
When should I take action against sweet potato virus disease?
Rogue symptomatic plants as soon as they appear and control vectors; never take cuttings from a symptomatic mother plant.
How do I control sweet potato virus disease?
Prevent — start clean (your strongest tool): plant only virus-tested clean or certified vines, or sprouts you know are healthy. This is the single most effective thing you can do — it stops the disease before it ever enters your field. When you cut your own vines, positively select: take cuttings ONLY from strong, fast-growing, symptom-free mother plants, never from weak or mottled ones.
Which crops does sweet potato virus disease affect?
Among the crops covered here: Sweet potato.
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.
Check what grows on your farm