Effect of rainfall gradient and previous crop on weed flora diversity in pearl millet (Pennisetum glaucum [L.]) crop under Sudano-sahelian conditions of Senegal

A study was conducted to determine the effect of climate gradient and previous crop on weed flora structure in pearl millet crop. Thus, floristic surveys were carried out during ۲۰۱۶ and ۲۰۱۷ crop years on station in Sahelian, Sudano-sahelian and Sudanian zones of Senegal. The results revealed that flora consisted of ۸۱ species distributed in ۵۹ genera and ۱۹ families. Higher number of species were recorded in Sudanian zone (Kolda and Séfa) with respectively ۶۱ and ۴۵ species and the lowest number of species were found at Vélingara in Sudano-sahelian zone (۲۸ species) and Sinthiou Malème in sahelian zone (۲۸ species). According to previously crop, the higher number of species was registered in previous fallow (۶۴ species) followed by previous pearl millet (۵۷ species). In previous mucuna and peanut, flora is ۱۴ percent lower than species recorded in previous fallow. Spectrum analysis indicated that the flora is largely dominated by therophytes, which includes ۸۱.۵% of the recorded species. It’s presence in pearl millet field was higher in Sahelian zone (۹۳%) followed by Sudano-sahelian zone (۸۹%) and Sudanian zone (Kolda and Séfa) with respectively ۸۰ and ۸۴% of recorded species. Domination of therophytes is more accurate in plot with previous fallow (۸۶%) followed by previous millet (۸۲%), previous peanut (۸۱%) and previous mucuna (۷۹%). Also, it was observed a decreasing of perennial species from Sudanian to Sahelian zone.

Keywords:

Pearl millet , Previous crop , Rainfall gradient , Senegal , Weed flora