Weed Specie Composition and Diversity as Influenced by Poultry Manure Rates and Weeding Frequency in Okra
Adeyemi, O. R; Olaogun, O; Adigun, J. A; Adejuyigbe, C. O

Yield losses in okra are often aggravated by the soil fertility status, weed types and degree of infestation on the field. Field trials were conducted during the early and late wet seasons of 2012 to investigate the influence of poultry manure rates and weeding regime on weed species composition and weed species diversity in okra. The experiment was arranged in a split- plot fitted into a Randomized Complete Block Design with three replicates. The main plot consisted of five poultry manure rates (0, 5, 10 and 15 t ha-1) while the sub plots were five weeding regimes namely: weedy check, weeding at 3 weeks after sowing (WAS); weeding at 3 and 6 WAS; weeding at 3, 5 and 7 WAS and weeding at 3, 6 and 9 WAS. Data were collected on weed specie composition, growth and yield of okra. Data collected were subjected to ecological analysis and analysis of variance as appropriate and significant treatment means were separated using Duncan Multiple Range test at p <0.05. The result shows that thirteen (13) and seventeen (17) weed species were observed in the early and late wet seasons respectively with broadleaves being the most prevalent. In the early wet season weed species diversity (Shannon index H’) (WDI) were mostly reduced in plots weeded 3, 6 and 9 WAP) while the greatest WDI reduction was recorded in plots weeded 3, 5 and 7 WAP. WDI was greater in late wet season than early wet season. Weed dry weights were negatively and significantly correlated with total fruit yield (r = -0.81 and - 0.90) in both early and late wet season respectively. It is therefore concluded that weed types and intensity could be influenced by manure rates and weeding regimes in okra.

Full Text: PDF     DOI: 10.15640/jaes.v4n1a28