Objective: Striga gesnerioides (Willd.) Vatke is one of the most important parasitic weeds affecting cowpea production in Burkina Faso. This study was designed to establish a clear geographic distribution of Striga gesnerioides and identifies its alternate hosts in Burkina Faso:
Methodology and Results: A prospection was undertaken in all parts the country. A minimum distance of 25 km was observed between sampling sites. The sampling sites were mainly naturally Striga infested fields and fallows. The results showed that Striga gesnerioides is found to be parasitizing cowpea and other alternate hosts in the four phytogeographical sectors of the country. However, the degree of infestation increases from the South to the North. During the prospection, five (05) weeds species were identified as alternate hosts of S. gesnerioides. These were Cassia mimosoides, Alysicarpus ovalifolius, Ipomea eriocarpa, Ipomea sp, and Thephrosia pedicellata. In addition, four (04) morphotypes of Striga gesnerioides were all found to be parasitizing both wild plants and cowpea (Vigna unguiculata).
Conclusion and application of results: From these results, a genetic diversity study can be undertaken in order to determine the intraspecific genetic variability within Striga gesnerioides in Burkina Faso. This could allow a clear identification and mapping of the different races of Striga occurring in the country. The determination of the geographic distribution of the different races will facilitate the adoption of new strategies for controlling Striga.

Burkina Faso, geographical distribution, morphotypes, Striga gesnerioides, alternate host