Cotton R&D in Africa

Cotton (Gossypium hirsutum)

Cotton is the major source of cash income and foreign exchange in Sub-Saharan Africa (Hillocks, 2009). Insect pests especially cotton bollworms are the major constraint to cotton production in Africa (Hillocks, 1995; Javaid, 1995). African institutions in partnership with Monsanto Company are field testing Bt cotton expressing cry1Ac and cry2Ab and herbicide tolerant cotton (Biotech Uganda, 2010; Dahi, 2012; Waturu et al., 2008). The Bt cotton showed improved resistance against the bollworms in Egypt (Dahi, 2012). Bt cotton significantly reduced the bollworm populations in Kenya (Waturu et al., 2008). Bt cotton and herbicide tolerant cotton field tested in Uganda showed improved resistance to cotton bollworms and improved herbicide tolerance respectively (ABSPII,; Biotech Uganda, 2010; Miti, 2009). The specific genes, approaches and participating institutions are summarized in the table below.


GM cotton (Gossypium hirsutum)

Bollworm resistance

1.    Importance of the cotton bollworm

·   Cotton bollworms are the most damaging insect pests causing yield losses of up to 60% 6

2.    Damage by the cotton bollworm

·   Bollworm larvae feed on leaves, flower buds, flowers and bore into fruits/pods6.

3.    Susceptible varieties

·   Most cultivated cotton varieties6

4.    How cotton bollworms are spread

·   Fully grown larvae pupate in soil, adults emerge & lay eggs on host plants, which coincides with early flowering of host plants6.

5.    Management practices

·   Synthetic pesticides, inspecting for eggs or young larvae before they enter fruits, destroy plant debris after harvesting, plough soil after harvesting to expose pupae to the sun and natural enemies, crop rotation, biological control4, 6, 7

6.    Limitations of the commonly used management practices

·   Synthetic pesticides are expensive for the resource poor farmers and pose risk to human health & the environment, cultural practices are labour intensive & limited control by biological agents4, 6, 7

7.    Limitations to conventional breeding

·   Limited sources of bollworm resistance in cultivated cotton4.

8.    Potential sources of resistance for genetic engineering under development

·   Bt cry genes (cry1Ac, cry2Ab)5

9.    Mode of resistance

·   When cry proteins are consumed by insect larvae, they are cleaved under alkaline conditions. The resultant activated toxin binds to the gut membrane forming pores that lead to death8, 10

10. Research partners

·   Monsanto, NARS (Uganda, Kenya, Egypt)3, 9 11

11. Stage of development

·   Confined field trial-Uganda, Kenya, Egypt2, 3, 11.

NARS: National Agricultural Research Systems.



1.        Agricultural biotechnology support project II (ABSPII). Cotton – Uganda. (accessed 13 December 2012).

  1. Biotech Uganda. 2010. Uganda approves second phase of GM trials. (accessed 13 December 2012).
  2. Dahi, H. F. 2012. Field performance of genetically modified cotton varieties (Bt cotton) expressing insecticidal-proteins cry1Ac and cry2Ab against cotton bollworms. Nature Science, 10(7): 78-85.
  3. Hillocks, R.J. 1995. Integrated management of insect pests, diseases and weeds of cotton in Africa. Integrated Pest Management Reviews, 1: 31-47.
  4. Hillocks, R.J. 2009. GM cotton for Africa. Outlook on Agriculture, 38(4): 311-316.
  5. (accessed 26 January 2013).
  6. Javaid, I. 1995. Cultural control practices in cotton pest management in tropical Africa. Journal of Sustainable Agriculture, 5(1-2): 171-185.
  7. Li, H., Oppert, B., Zhu, K.Y., Higgins, R.A., Huang, F and Buschman, L. 2003. Transgenic plants expressing Bacillus thuringiensis delta-endotoxins. Entomologia Sinica, 10(3): 155-166.
  8. Miti, J. 2009. Uganda’s GM cotton trials are promising. (accessed 13 December 2012).
  9. , Yul, J., Choi, J.Y., Li, M.S., Jin, B.R and Je, Y.H. 2007. Bacillus thuringiensis as a specific, safe and effective tool for insect pest control. Journal of Microbiology and Biotechnology, 17(4): 547-559.
  10. Waturu, C.N., Wessels, W., Kambo, C.M., Wepukhulu, S.B., Njinju, S.M., Njenga, G.K., Kariuki. J.N., Karichu, P.M and Mureithi, J.M. 2008. Efficacy of Bt cotton against African bollworm (Helicoverpa armigera) and other arthropod pests. Proceedings of the 1st All Africa Congress on Biotechnology, 22-26 September 2008.