Cabbage is an important crop in Ghana where it grows all year round, right across the country. It is mainly grown for commercial production in Southern Ghana, in Akwapim and Kwahu areas and in the moist high elevations around Tarkwa.
Growing cabbage in Ghana is challenging since it can be attacked by a variety of pests, such as cabbage aphids, caterpillars, cabbage webworm, diamondback moth, mole cricket, snails and rodents. Worldwide, aphids are a major concern because they commonly spread plant-infecting viruses. These are often diagnosed as turnip mosaic virus and cauliflower mosaic virus, particularly in Europe and the US, according to Dr John Carr, University of Cambridge, UK (Phys.org, 2017).
Two years ago, farmers in Ghana started noticing that cabbages in some fields were stunted, turning yellow and wilting, with leaves curled and dotted with mould. The timing of the damage appeared to correlate with aphid infestations; however, the kind of damage caused did not seem to be solely due to the sap-sucking habits of this pest. Scientists therefore believe that the aphids are acting as the vector of a virus, but one which has not been recorded before in Ghana (Phys.org, 2017).
In response to this finding, molecular biology methods are currently being used by Dr Ken Fening, University of Ghana, and Dr John Carr, University of Cambridge, to determine the virus which is causing the damage, in the hope that doing so will enable effective management and control techniques to be developed and used against the virus (Phys.org, 2017).
For more information, you may like to read Of cabbages and cows – increasing agricultural yields in Africa on which this article is based.
You can visit our Plantwise Knowledge Bank for information on:
- Cabbage aphids: Pest management decision guide, Factsheet for farmers
- Mosaic viruses on Brassica: Factsheet for farmers
- Aphids on Brassica: Factsheet for farmers
- Green peach aphid (Myzus persicae): Technical factsheet
CABI, 2017. Plantwise Knowledge Bank. http://www.plantwise.org/KnowledgeBank/ [Online]. Accessed 21/02/2017. Wallingford, UK: CAB International.
Ministry of Food and Agriculture, 2017. Cabbage Production. Ghana: Government of Ghana. http://mofa.gov.gh/site/?page_id=14160 [Online]. Accessed 21/02/2017
Phys.org, 2017. Of cabbages and cows—increasing agricultural yields in Africa. UK: Phys.org. https://phys.org/news/2017-02-cabbages-cowsincreasing-agricultural-yields-africa.html [Online]. Accessed 21/02/2017.