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.