Effect of sowing date and genotype on pearl millet yield across semi-arid regions of Sub-Saharan Africa

Abstract

In climate change–vulnerable, food-insecure semi-arid regions of Sub-Saharan Africa, limited studies compared the performance of pearl millet [Pennisetum glaucum (L.)] landraces and improved genotypes under staggered sowing to establish their interactions, resulting in a generalization that landraces are lower yielding than their improved counterparts. A 3-year field experiment was conducted to compare grain and biomass production of an improved Okashana-2 and the landrace Kantana pearl millet genotypes under five sowing dates between January 1 and March 1 in semi-arid North-Central Namibia. Across years, Kantana sown on January 1 produced the highest grain and shoot biomass yields, ranging from 0.5 to 9.5 t ha−1 and 2.6 to 31.4 t ha−1, respectively, with both gradually declining with sowing delays. Higher grain and biomass yields in early-sown Kantana were due to its longer vegetative growth phase, nearly 2 weeks longer than that of its Okashana-2 counterpart, allowing more time for normal growth and development before heading. Okashana-2, on the other hand, attained its highest yields under January 1 or January 15 sowing dates, with grain and biomass yields ranging from 0.8 to 7.4 t ha−1 and 1.7 to 18.6 t ha−1, respectively, fluctuating among sowing dates; however, March 1 sowing produced the lowest yields. The variable yields for Okashana-2 indicate the genotype’s ability to respond rapidly to soil moisture from various rainfall events. These results demonstrate that maximum pearl millet yields in northern Namibia are achievable by sowing Kantana by January 1, while Okashana-2 has higher and relatively stable yields under late sowing. However, farmers must promptly acquire production inputs and services to facilitate early sowing