Agronomic performance of pearl millet genotypes under variable phosphorus, water, and environmental regimes

Abstract

Water and P deficiency can significantly limit pearl millet [Pennisetum glaucum (L.) R. Br.] productivity and response to N application in the arid and semi-arid regions of Africa. The objectives of this research were to quantify the responses of improved pearl millet genotypes and a landrace to contrasting rainfall gradient and P deficient soil conditions across different locations in Niger. The study was conducted at four locations: (a) Tara, (b) the International Crop Research Institute for the Semi-Arid Tropics (ICRISAT) research station at Sadoré, (c) Maradi, and (d) Araourayé, Niger, during 2015 and 2016 rainy seasons. Results of the study indicated that the effect of P fertilizer application on shoot weight, panicle weight, grain yield, and harvest index was different by environment (year × location). As high as 113% straw yield, 72% panicle weight, and 100% grain yield advantage was obtained with P application over low P in favorable environments. Across all genotypes and in both P treatments, irrigation had a consistent effect on the agronomic performance. On average, there was significantly greater straw yield (629 vs. 492 g m–2), panicle weight (472 vs. 229 g m–2), grain yield (257 vs. 122 g m–2), and harvest index (0.25 vs. 0.15) in the irrigated site compared with rainfed sites. Among the tested genotypes, Mil de Siaka showed relatively consistent performance in irrigated, water deficit, and P deficient conditions, emerging as an ideal candidate for inclusion into pearl millet breeding programs, aimed toward developing multi-stress tolerant pearl millet varieties.