Influence of plant spacing on weed suppression and maize performance in the humid forest agro-ecology of south eastern Nigeria
Field experiment was conducted at the Department of Crop and Soil Science Demonstration Plot, Faculty of Agriculture, University of Port Harcourt, Nigeria between April and October, 2017 to evaluate the effect of maize plant spacing on weed suppression and maize performance in the humid forest agro-ecology of South-Eastern Nigeria. The treatment consisted of five plant spacing: 50 cm x 25cm, 75cm x 25cm, 100 cm x 25 cm, 75cm x 50 cm and 100 cm x 50cm which was equivalent to five population densities (80,000; 53,333; 40,000, 26,667 and 20,000 plants /ha). The treatments were arranged in a Randomized Complete Block Design (RCBD), and replicated four times. Data collected on weeds were weed density and biomass, while maize data were count at emergence, height, leaf area index, stands at harvest, total plant weight at harvest, cob number, cob dry weight and grain yield. Result showed that spacing had no significant (P 0.05) effect on weed density but had on weed biomass. Plant spaced at 100 cm x 25cm had the highest weed biomass (190.53g/m2) but did not differ significantly from other plant spacing except for 75 x 50 cm. Spacing had significant (P 0.05) effect on all agronomic maize data assessed, except for plant height, cob dry weight and grain yield. Though there were no significant differences in grain yield among the different plant spacing, plants spaced at 75 cm x 25cm had the highest grain yield (1704 kg/ha) followed by 50 cm x 25 cm (1666.7kg/ha) plant spacing. In order to attain better weed control and high maize performance, farmers are encouraged to plant maize at a spacing of 75cm x 25cm or at closer spacing of 50 cm x 25cm with one plant per hill.
Keywords: Maize, weed suppression, spacing and weed control