Parasitic plants such as Striga hermonthica and Striga gesnerioides represent a real plague of parasitism on cultivated host plants. The main objective of this study is to assess the knowledge levels of growers on Striga hermonthica and Striga gesnerioides. A participatory approach was used, including the Communal Directors of Agriculture of five (5) communes, as well as producers in each target village. This study shows that 95% of producers confirm the presence of Striga hermonthica in millet fields and 89% of producers also mention the presence of Striga gesnerioides in cowpea fields. Among the wild host plants, eleven (11) are identified for Striga hermonthica and four (4) for Striga gesnerioides. According to producers, the symptoms of the attack of these parasitic plants that reduce millet and cowpea yields remain yellowing, stunting, reduced tillering / branching, poor development of ears/pods and the presence of millet stem borers. However, producers use control techniques such as hand-pulling, use of manure and use of host plant association techniques with sesame. These results can contribute to the development of effective control methods against Striga hermonthica and Striga gesnerioides.

140 sesame accessions (Sesamum indicum) collected in different regions of Niger were characterized through 16 agro-morphological characters. These characters showed a great diversity within this collection. However, no link has been highlighted between this diversity and the geographical isolation of the collected accessions. The principal component analysis (PCA) and the hierarchical classification on the principal components (HCPC) highlighted three agromorphological groups. The group 1 accessions are the earliest and with a low vegetative development but very productive. Those of group 2 have an average precociousness and a vegetative development but as productive as those of group 1. Group 3 is that of the late ones with a very important vegetative development but low yields. The early rain cessation in September, before the end of their cycle, certainly impacted their productivity. The most discriminating variables that describe the variability between the identified groups are the precocity characters (date of start of flowering, date of 50% flowering, date of start of flower buds and physiological maturity) and vegetation characters (number of branches on the main stem, number of nodes on the main stem and length of internodes). Some accessions, with good agronomic performance, have been identified to be multiplied and distributed directly to producers or to integrate future sesame selection programs in Niger.