Cocoa Pollination for Optimised Production

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Background and rationale to the project

Despite the importance of cocoa as a major cash crop of the tropics, the pollination biology of cocoa remains neglected.  Pollination rates are generally poor for cocoa and inconsistent across the year but recent evidence indicates that improving pollination can improve yield [1]. For example, manual pollination of cocoa has been shown to increase fruit set, the number of mature pods and the number of seeds per pod [2]. However, controlled studies showing the effects of variable midge pollinating rates are not available. Despite this, it is widely recognized that midges should be encouraged on cocoa farms - for example, by leaving plant litter around plantations for colonisation by midges and food for larvae [3]. The impact of such action on cocoa yield has not yet been quantified and is a key objective of the CocoaPOP project. It is also unknown how effective these midges are at pollinating, what attracts them to cocoa flowers and how visitation benefits the midges, thereby encouraging them to visit one flower or several. Generating knowledge about these midges and their role in cocoa pollination and how this information can be used to optimise yields of cocoa is the primary objective of the CocoaPOP project.

[1] Groeneveld, J.H., Tscharntke, T., Moser, G., Clough, Y. (2010) Perspect Plant Ecol Evol Syst 12:183-91.

[2] Falque, M., Vincent, A., Vaissiere, B.E., Eskes, A.B. (1995) Sex Plant Reprod 8:354–60; Goda Sporn, S., Bos, M.M., Robbert Gradstein, S. (2007) Agr Ecosyst Environ 122:490-3; Young, A.M. (1982) J Appl Ecol 19(1):47-63.

[3] Winder, J.A., Silva, P. (1972) Bull Ent Res 61:651-55; Young, A.M. (1982) J Appl Ecol 19(1):47-63; Young, A.M. (1994) The chocolate tree: A natural history of cacao. 1st ed. Smithsonian Institution Press, Washington and London.