Weed communities in intensified cereal‐based cropping systems of the northern Guinea savanna

Abstract

SummaryThe dynamics of weed populations were ana lysed in intensified cereal‐based cropping sys tems of the northern Guinea savanna in Nigeria, A total of four common weed associations were identified through cluster analysis. Five factors describing soil fertility conditions and field his tory best differentiated the weed communities according to a discriminant model. The analysis shows that maize‐based cropping systems with a high frequency of cereal cropping and a low fre quency of noncereal cropping tended to be domi nated by weeds such as Commelina spp. and Kyllinga squamulata. As soil fertility declined, Vernonia spp. and Eclipta prostrata became more important. Increased frequency of noncereal crops in mixed cropping with cereals was associ ated with reduced incidence of weeds such as Leucas martinicensis, Oldenlandia corymbosa, Spermacoce verticillata, Litdwigia hyssopifolia, Celosia laxa, and,Ipomoea spp. Further diversifi cation of cereal‐based systems to obtain a re duced frequency of cereals is likely to increase the incidence of Dactvloctenium aegyptium in crop fields. The information provides guidance for technology development and transfer on weed control for intensifying systems in the northern Guinea savanna of Africa.