ABSTRACT
The study was carried out at an existing field at Green hills cassava farm stead, IkpobaOkha Local Government Area, Edo State Benin City in Nigeria. This study investigated the composition of herbicide resistant bacteria in the rhizosphere of a cassava plant cultivated in ultisols. Soil samples were collected with a soil auger from a field and treated with Pre-emergence herbicide Tackum, and post emergence herbicide, Vigor, and a control plot. Soil samples were taken to the laboratory for analysis using the various standard laboratory procedures for chemical and biological analysis. The soil sample was tested for pH, Organic carbon, Total Nitrogen Content, Available phosphorus, and potassium. The control plot exhibited higher Total Nitrogen Content, Organic content, Organic matter, and available phosphorus content. Bacteria counts were highest in the plot treated with preemergence herbicide, followed by the control, and then the plot treated with both pre and post emergence herbicide. High bacteria count in the plot treated with preemergence herbicide highlights the potential impact of herbicide application on soil microbial communities. The isolates were tested for their ability to fix atmospheric nitrogen (N2), produce ammonia (NH3) and indole acetic acid (IAA) and solubilization of phosphate (PO4). All the isolates (Klebsiella spyyyyyyyyyyyyecies, Pseudomonas aeruginosa, Escherichia coli, Bacillus subtilis, and Enterobacter aerogenes) exhibited the ability to enhance nitrogen availability in the soil. Klebsiella species, Escherichia coli, and Bacillus subtilis showed positive results for ammonia production which is beneficial to plant growth. Klebsiella species, Bacillus subtilis, and Enterobacter aerogenes were capable of producing the phytohormone indole acetic acid (IAA). However, all isolates exhibited the ability to solubilize phosphate.
