Abstract

Hydropriming of pearl millet seeds was tested during two growing seasons in Burkina Faso. A total of 32 field experiments were distributed equally between two agro-ecological zones: The Northern zone receiving on average less than 600 mm annual precipitation and the Central zone receiving 600 to 900 mm. Hydropriming was performed by soaking of seeds in water for 6 h, followed by air-drying overnight. In the Northern zone, an increase of both emergence and yield was observed for hydroprimed seeds in both years of testing. This was reflected by a higher yield observed in 13 out of 16 field experiments, increased median yield (+159 kg/ha; p<0.0053) and an increase of the relative yield by +29% as a field average (p<0.000054). In contrast, in the Central zone a net negative effect on crop emergence was observed in both years, and only 5 out of 16 field experiments showed a yield increase for hydroprimed seeds. Meteorological data confirmed the difference in rainfall between the two zones. Hydropriming by 6 h of soaking and drying of seeds overnight appears as a simple method to increase yield of pearl millet significantly in the most arid out of two agro-ecological zones tested in Burkina Faso. Drying of seeds overnight is a novel agronomically feasible approach, allowing a full day for subsequent sowing.     

Key words: Seed-priming, hydro-priming, Sahel, millets, location-dependent effect.