Effect of the timing of water deficit on growth, phenology and yield of pearl millet (Pennisetum glaucum(L.) R. Br.) grown in Sahelian conditions

Abstract

Several studies conducted under high input conditions have indicated little susceptibility of pearl millet to water deficit untill early grain filling, because the losses in main shoot production were fully compensated by increased tiller fertility. The present study assessed the impact of water deficits at three development stages: prior to flowering (S30), at the beginning of flowering (S45), and at the end of flowering (S60) in pearl millet grown in experimental conditions similar to Sahelian farming conditions. It included a control irrigation treatment simulating the natural distribution of rainfall throughout the cropping season. Both biomass production and grain yield were severely reduced by S30 and S45, while S60 had no effect. In S30 and S45, the flowering of tillers was delayed or totally inhibited. In both of these treatments, the low number of productive tillers did not compensate for damage to panicle initiation and flowering of the main shoot. All treatments maintained green leaves on the main shoot during the grain filling period, and in S30 leaf growth recovered from mid-season drought. These results illustrate how pearl millet mostly escapes drought by matching its phenology to the mean rainfall distribution in the Sahel. In the case of mid-season drought, some late productive tillers and the maintenance of green leaf biomass of the main shoots limited, but did not overcome, the yield losses. This study stresses the importance of agro-ecological conditions in control treatments, particularly the water regime and crop density, when assessing crop drought resistance.

Deep Root Water Uptake Ability and Water Use Efficiency of Pearl Millet in Comparison to Other Millet Species

“…Since the ability to take up water from deep soil layers and WUE seem to operate largely independently on drought tolerance (Passioura, 1983), drought-tolerant millet species may have either one or both of these traits but not necessarily both of them. Many studies have stressed the ability of pearl millet to avoid drought stress by phenological, physiological, and morphological characteristics at the canopy level (Singh and Singh, 1995;Do et al, 1996;Levy et al, 1997;Winkel et al, 1997;, but only a few investigated the ability of pearl millet to take up water from the whole soil profi le (Zaongo et al, 1994;McIntyre et al, 1995). There is no quantitative information on the ability of the deep roots of pearl millet to extract water from wet subsoil layers when topsoil is prone to drought.…”

Weather-index drought insurance in Burkina-Faso: assessment of its potential interest to farmers

“…Several factors can explain this dispersion. First, cumulative rainfall is not a perfect proxy for yields: for a given rainfall amount, intraseasonal distribution can have significant effects on yields (Winkel et al 1997). Moreover, rainfall is not the only climatic variable impacting yields: radiation and temperature also influence crop productivity.…”

Drought Adaptation in Millets

“…Early stress: water stress from two weeks after emergence until symptoms of stress observed. A study by Winkel et al [52] in Niger where the annual rainfall is around 200 mm investigated the impact of water deficit at three stages of pearl millet development. The three stages were prior to flowering, at flowering and at the end of flowering.…”