Effect of inter-row spacing and plant population on weed dynamics and maize(Zea mays L.) yield at Zanyokwe Irrigation Scheme, Eastern Cape,South Africa

Abstract

A study was conducted to determine the effects of inter-row spacing (45 and 90 cm) and plant population (40000 and 60000 plants ha-1) on weed biomass and the yield of both green and grain materials of maize plants. The experiment was set up as 2 × 2 factorial in a randomised complete block design with three replications. Plant population had no significant effects and interaction among factors was not significant on weed biomass. Narrow rows of 45 cm reduced weed biomass by 58%. Growing maize at 40000 plants ha-1 resulted in similar green cob weight regardless of inter-row spacing. Cob length decreased with increase in plant population and with wider rows. Similar grain yield was obtained regardless of inter-row spacing when maize was grown at 40000 plants ha-1, but at 60000 plants ha-1, 45 cm rows resulted in 11% higher grain yield than 90 cm rows. Increasing plant population from 40000 to 60000 plants ha-1 resulted in a 30% grain yield increase. The study demonstrated that growers could obtain higher green and/or grain yield by increasing plant population from the current practice of 40000 to 60000 plants ha-1 and through use of narrow rows. Key words: Row spacing, plant population, weed density, weed biomass, maize yield.