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Groundnut rosette virus complex Groundnut rosette virus (Umbravirus arachidis) with its satellite RNA, and groundnut rosette assistor virus (Polerovirus GRAV) · formerly or also: GRD, GRV + sat-RNA + GRAV
Groundnut rosette is the most destructive virus disease of groundnut in sub-Saharan Africa. Infected plants are severely stunted and bushy, with small, curled leaves that are either yellow ('chlorotic rosette') or dark green and mottled ('green rosette'). The disease is caused by three agents that depend on each other and is spread by the groundnut aphid, Aphis craccivora. Plants infected early produce almost no pods.
Groundnut rosette disease is caused by Groundnut rosette virus complex Groundnut rosette virus (Umbravirus arachidis) with its satellite RNA, and groundnut rosette assistor virus (Polerovirus GRAV), a virus complex (an umbravirus, its satellite RNA and a polerovirus), spread by aphids (order Tolivirales (umbravirus) and Sobelivirales (polerovirus), family Tombusviridae (umbravirus) and Solemoviridae (polerovirus)).
Older or alternative scientific names: GRD, GRV + sat-RNA + GRAV.
Found only in sub-Saharan Africa and nearby islands, including Madagascar; chlorotic rosette is widespread across the region, while green rosette occurs mainly in West Africa and has been reported in East Africa.
| Region | Status |
|---|---|
| West Africa | Widespread; major epidemics in the past |
| East and southern Africa | Widespread |
| Elsewhere | Not recorded outside Africa |
The disease involves groundnut rosette virus (an umbravirus with no coat protein of its own), a satellite RNA that causes most of the symptoms, and groundnut rosette assistor virus (a polerovirus). The assistor virus provides the protein coat that allows aphids to transmit the complex. Aphids carry it in a persistent way, for life after acquisition. It is not seed-borne. Because all three agents are needed, plants can carry the assistor virus alone without symptoms, which complicates diagnosis.
| Crop stage | What you see |
|---|---|
| Early infection (seedlings) | Severe stunting and bushy growth; leaves small, curled and yellow or dark green with mosaic; plants produce few or no pods. |
| Later infection | Symptoms on part of the plant; reduced pod number and size. |
| Field pattern | Scattered affected plants early, then expanding patches as aphids move within the field. |
Between seasons the virus complex survives in volunteer groundnut and possibly in other plants. Winged groundnut aphids acquire it while feeding and carry it to new crops. Infected plants then serve as sources for aphids within the field. Because rosette spreads from plant to plant, sparse or late-planted crops that aphids land on easily are most affected.
| Stage | Duration | Notes |
|---|---|---|
| Survival in volunteers and other hosts | Between seasons | Few sources needed to start an epidemic. |
| Aphid acquisition and transmission | Hours of feeding; aphids then carry it for life | Persistent. |
| Symptom development | About 2-3 weeks | Early infection causes most loss. |
| Secondary spread | Through the season | From infected plants within the field. |
Epidemics follow aphid build-up, which is greatest in dry spells, especially early in the rainy season.
Spread continues while aphids are active.
Late sowing, low plant density and patchy stands that attract aphids, dry spells that favour aphid build-up, volunteer groundnut, and susceptible varieties.
There is no economic threshold; management is preventive, using early sowing, dense stands and resistant varieties.
Thresholds are local. They depend on crop price, control cost, variety and natural-enemy activity, so use the figure your local extension service publishes where one exists.
Plants infected early produce almost no pods. Epidemics have caused large regional losses in the past, and the disease remains a major constraint to groundnut production on smallholder farms in Africa. Losses vary greatly between years, depending on aphid numbers early in the season and on sowing date.
Control works best as a sequence: prevent, monitor, then act only when a threshold or a risk forecast says so, using the least disruptive option that works.
Seed treatments and sprays against aphids can delay spread, but are rarely economic for smallholders compared with early sowing, dense planting and resistant varieties. What is registered differs by country and changes over time; follow the label and your local plant-protection authority.
| Scheme | Group | Mode of action | Notes |
|---|---|---|---|
| IRAC | 4A | Nicotinic acetylcholine receptor competitive modulators (neonicotinoids), seed treatment against aphids | Toxic to pollinators. |
Groundnut is the only important crop host; a few weeds and other legumes have been infected experimentally.
How to grow the crop well is the first line of defence. Laisha's free grow guides cover each crop from sowing to harvest:
Written by Laisha from the sources above, in its own words. This page is general reference, not a prescription: confirm identification locally and follow the label and your plant-protection authority.