Competition in Maize by Annual Weeds І Annual Variability in competition Effects due to Rainfuall an dNitrogen Fertilizer

Abstract

Statistical analyses were undertaken on data relating to the competition effects of annual weeds (Brachiaria sp, Euphorbia sp, and others) on maize yield, with and without nitrogen fertilization, and between years, of differing rainfall patterns. Linear regression relationships were established between the duration of weed competition and final maize grain yield. There was year-to-year variability in the effects of competition reflecting both rainfall pattern and nitrogen fertilization. Very verly competition and high yield losses resulted in very wet years when maie was grown in teh absence of nitrogen fertilization.