Groundnut plant residue at different placements in the soil was tested for phytotoxic and other effects on the growth and development of groundnut and maize plants. Results indicated that the residue released substances during decomposition that inhibited growth and development of groundnut. Residues mixed with the soil or banded in a layer below the seed was the most inhibitory to the growth of groundnut. However, early maize growth was stimulated by the presence of residue on the soil surface or in the soil