Plant Density and Nitrogen Fertilizer Effects on Pearl Millet Production in Niger

Pearl millet ( Pennisetum glaucum [L.] R. Br) is an important crop in many developing countries in West Africa and provides 80 to 90% of the food requirement for Niger. Farmers plant at a wide range of densities which may affect crop response to fertilizer. Studies were conducted for 3 yrs in a sandy soil in southern Niger to assess the effects of N fertilization (0–60 kg N ha −1 ) and plant density (5000–40 000 pockets ha −1 , three plants per pocket) on millet yield and yield components. The effects of N and density on yield were influenced by midseason rainfall. With low midseason rainfall, highdensity planting reduced yield slightly and N had no effect. With average or above rainfall, N application and high plant density increased millet grain yield four‐ to fivefold. Nitrogen increased stover production 33% in a dry year and 100% in the wetter year. Plant density significantly affected stover yield only in 1983, a year with high early season rainfall. Increasing plant density tended to increase stover production in all years. Grain weight in 1983 decreased 14% when plant density exceeded 20 000 pockets ha −1 . Nitrogen fertilizer doubled the number of heads per pocket at low plant densities when rainfall was normal or above. A plant density of 15 000 to 20 000 pockets ha −1 and N application of 30 kg N ha −1 in two splits achieved good yields in average and wet years, with only a small yield reduction in the drought year.