Divisi
Cucurbit mosaic virus
Watermelon mosaic virus · Viral
Photo: Dr. Jan Hinrichs-Berger, Landwirtschaftliches Technologiezentrum Augustenberg, Karlsruhe. · CC BY 4.0
Cucurbit mosaic (Watermelon mosaic virus and related potyviruses) is a virus disease of cucumber, pumpkin, squash, melon and watermelon. Winged aphids carry it on their mouthparts and pass it from plant to plant in seconds as they probe (a non-persistent virus — caught and spread almost instantly). It survives the off-season in weeds and volunteer cucurbits, then rides warm-weather aphid flights into the crop, so early plots next to old fields and weedy edges are hit first.
Downtowngal · CC BY-SA 4.0 
OllieMartin on WikiGardener · CC BY-SA 3.0
Why it matters
Cucurbit mosaic can take up to half your crop (50%) — the vines stay stunted and the fruit come out mottled, warty and misshapen, so buyers won't take them. The hardest part: once a plant catches the virus there is no cure and no spray that fixes it — the plant carries it for life. And because aphids pass it in seconds as they probe a leaf, it moves through a field fast before you even see the insects. Your only real power is to keep it out and pull out sick plants early.
When to act
Rogue at first mosaic symptom; act on aphids before winged migrants build up.
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 cucurbit mosaic virus field guide
- Identify it
- Scout for it
- Control it
13 field-guide sections in the app
The full guide to cucurbit mosaic virus — 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 cucurbit mosaic virus?
What you see first: on the youngest leaves at the shoot tips, a patchy bright yellow-green mosaic — light and dark green mixed together like a patchwork quilt, not an even yellowing. The leaf often puckers and blisters, with raised bumpy areas between the veins.
When should I take action against cucurbit mosaic virus?
Rogue at first mosaic symptom; act on aphids before winged migrants build up.
How do I control cucurbit mosaic virus?
Prevent first — best protection is a resistant variety: grow mosaic-tolerant cucurbit varieties suited to your area. This is the single strongest tool you have, because it protects the plant even when aphids do land on it.
Which crops does cucurbit mosaic virus affect?
Among the crops covered here: Cucumber, Egusi melon, Watermelon.
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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