Abstract

Wheat productivity in southern Niger is hampered by the utilization of local wheat varieties that exhibit a low response to fertilizer. A field experiment was conducted over two dry seasons in Djirataoua to investigate the efficiency and responsiveness of four wheat varieties under four nitrogen doses (0, 100, 150 and 200 kg N ha-1). The experiment followed a split-plot design with three replications. Results revealed an increase in grain yield with rising nitrogen rates, peaking at 150 kg N ha-1. The wheat varieties exhibited varying responses to nitrogen, with Reyna-28 demonstrating higher grain yield and the local variety showing lower productivity. The most substantial grain yield was observed with the interaction of Reyna-28 and 150 kg N ha-1. Sokoll/3/ exhibited the best agronomic efficiency with the application of 100 kg N ha-1. The grain yield response index indicated that Reyna-28 was more efficient in nitrogen utilization, Sokoll/3/ was more responsive to nitrogen increase, while the local variety displayed neither efficiency nor responsiveness to nitrogen. Based on these findings, the recommended practice for maximizing wheat grain yield in this area is the application of 150 kg N ha-1, coupled with the use of Reyna-28.

Key words: Triticum aestivum, low-N, high-N, N-utilization, yield.