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 contro

Effect of crop spacing regimes on weed growth and performance of cowpea (Vigna unguiculata (L.) in a humid zone 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 August and December 2017 to determine the effect of crop spacing regimes on weed growth and cowpea variety IT90K-277-2 performances in the humid zone of Southeastern Nigeria. The treatments consist of three crop spacing regimes: 75cm x 25cm, 75cmx 30cm and 75cm x 35 cm. The treatments were laid out in a randomized complete block design (RCBD) and replicated four times. Results showed that crop spacing regimes had no significant (P > 0.05) effect on weed growth, in all the growth and yield traits of cowpea data assessed, except for stand counts. Therefore, intermediate spacing (75cm x 30cm) or wider spacing (75cm x 35cm) at two stands per hill is recommended to farmers for better weed control and higher grain yield of cowpea in the humid zone of Southeastern Nigeria because either of the spacing tends to be more economical than close spacing, since, no seeds were wasted. However, the study need to the repeated with economic analysis of the crop spacing regime as a variable to revalidate the results obtained from this study.Keywords: Cowpea, humid zone, spacing, variety IT90K-277-2, and weed growt

Weed Flora and Nutritional Composition of Cowpea Grains as Influenced by Some Pre Emergence Herbicides Application in Nigeria

Field experiment was conducted at the Teaching and Research Farm of Ambrose Alli University, Ekpoma, Edo. State, Nigeria to the evaluate influence of some pre emergence herbicides application on weed flora and nutritional composition of cowpea grains. The treatments consisted of no weeding (control), Coda goldÒ at 1.65 kg a.i./ha, Galex at 3.0 kg a.i./ha, Pendilin at 2.0 kg a.i./ha, One hoe weeding  at 3 weeks after planting (WAP) and Two hoe weeding at 3 & 7WAP laid out in a Randomized Complete Block Design (RCBD)  with  four replicates. The result showed that there were changes in weed flora composition of broadleaved weeds and grasses except sedges before and after experiment. For instance, approximately 52.38% of the weeds were broadleaved species and 28.57% were grasses before planting while about 38.1% of the weeds were broadleaved species and 42.86 % grasses after harvest. Before planting, annual weed species were 28.57% and perennial 71.43% while after harvest, annual weed species were 47.62% and perennial 52.39%. The result further showed that plot treated with herbicides had a slight increase in nutritional composition of cowpea grains when compared to hoe weeding and no weeding. Since, the herbicides used in the study altered weed flora composition of cowpea plant without having any adverse effect on the nutritional composition of the grains, they are recommendable to farmers for boosting cowpea production in Nigeria. Keywords: cowpea grains, nutritional composition, pre emergence herbicides, weed flora, DOI: 10.7176/JBAH/9-2-0