PhD defence Simon N’cho

SimonOn Monday 1 December 2014 Simon N'cho defends his PhD-thesis entitled: "Socio-economic impacts and determinants of parasitic weed infestation in rainfed rice systems of sub-Saharan Africa". The defence starts at 16hr and will be held at the Auditorium, building number 362 at the Generaal Foulkesweg 1, 6703 BG in Wageningen.


Rice is the world’s most important food crop in terms of the area harvested and caloric intake. In sub-Saharan Africa, rice has become an important strategic crop for achieving food security. However, domestic production cannot match the demand among others due to the yield losses caused by parasitic weeds. This thesis used econometric and mathematical programming techniques to determine the main factors that cause infestation of rainfed rice farms by parasitic weeds and to estimate the economic impact on rice producers. Findings indicate that parasitic weeds cause productivity losses ranging from 21% to 50% and that there is no evidence that farmers can manage parasitic weeds efficiently with the currently used manual weeding methods. The results of this thesis provide guidance to policy makers and farmers for developing strategies for coping with parasitic weeds more efficiently.


  1. Parasitic weeds in rainfed rice cannot be efficiently managed with the currently applied weeding strategies (this thesis).
  2. Rainfed rice farmers could save more than half of their weeding labour if they were operating fully technically efficient (this thesis).
  3. Soil management is the key to a sustainable decrease of the gap between actual and attainable crop yields, and therefore crucial for feeding the increasing world population.
  4. Increasing the competitiveness of agriculture is a precondition for Côte d’Ivoire to become an emerging economy.
  5. Mass migration to cities in Africa will reduce if income inequality between rural and urban populations is reduced.
  6. Reducing unemployment among young people in countries in West Africa will enhance the stability of the countries’ social and political environment.

More information can be found here.