Field trials conducted with groundnut(Arachis hypogaeaL.) at three different locations in Niger, using seed‐protectant chemicals, showed a large reduction in plant stand on non‐treated plots. The reduction in plant stand was largely due to pre‐emergence seed and seedling rots, caused byAspergillus niger, A. flavus, Rhizoctonia solani, Macrophomina phaseolinaand species ofRhizopus, FusariumandPythium.Losses in pod yields in non‐treated plots were substantial and varied over locations. Seed treatment with thiram was very effective in improving plant stand and pod yields at all locations.