Tag Archives: Resistance

Growth Performance of Eleven Improved Cassava Varieties and their susceptibility to Some Insect Pests and Diseases in Humid Tropics, Rivers State (Published)

Study on the agronomic evaluation and disease resistance of eleven improved cassava varieties was carried out in Rivers State University Teaching and Research Farm in a Randomized Complete Block Design (RCBD). The eleven varieties assessed are TMS 30572, TMS 98/0510, TMS 98/0581, TMS 98/0505, TMS 92/0326, TME 419, TMS 01/1371, TMS 01/1368, TMS 07/0593, TMS 95/0289 and TMS 96/1632 were evaluated for plant height, leaf number, number of branches, number of flowers, insect infestation and disease incidence. The plant height of the cassava varieties revealed that eight varieties (TMS 01/1371, TMS 01/1368, TMS 30572, TME 419, TMS 98/0505, TMS 96/1632, TMS 98/0510 and TMS 07/0593) are tall varieties while TMS 98/0581, TMS 92/0326 and TMS 95/0289 are short varieties. The highest leaf number was recorded in TMS 01/1371 but the tall varieties like TMS 01/1368, TMS 96/1632 and TME 419 had low leaf number. TMS 98/0581, TMS 92/0326 and TMS 95/0289 were shown to have scanty leaves. TMS 01/1371 was significantly higher (P<0.05) than other varieties in plant height, leaf number and branches. Four varieties flowered namely TMS 07/0593, TMS 01/1371, TMS 30572 and TMS 98/0505. TMS 30572 and TMS 92/0326 were highly susceptible to both African Cassava Mosaic and Xanthomona sp. (Bacterial blight diseases) while TMS 95/0289, TMS 01/1368 and TMS 98/0505 were less susceptible to African Cassava Mosaic virus disease alone. Insect infestations (White fly: Bemisia sp. and Mealybugs: Phenacoccus sp.) on the tested varieties were significantly minimal though five cultivars (TMS 98/0505, TMS 96/1632, TMS 98/0510, TMS 98/0581 and TMS 95/0289) were completely resistant. Therefore, there is urgent need to withdraw the varieties that are susceptible, and use more of the varieties that are disease resistant for high crop yield, breeding and higher productivity.

Keywords: Resistance, Varieties, cassava, susceptibility and agronomic assessment.

Antibacterial Effect of Gongronema Latifolium Leaf Extracts On Selected Gram Positive and Negative Clinical Bacterial Isolates (Published)

This work was aimed at assaying the in-vitro effect of aqueous and ethanolic leaf extracts of Gongronema latifolium on Pseudomonas aeruginosa, Staphylococcus aureus, Klebsiella pneumoniae and Escherichia coli. Six (6) milimetre sterile discs were impregnated with the aqueous and ethanolic extracts at different concentrations ranging from 6.25mg/mL to 100mg/mL. The test organisms were spread evenly on Mueller Hinton agar plate and the discs were aseptically placed on them. The sensitivity plates were incubated at 37ºC for 24 hours. All the test organisms showed sensitivity to both aqueous and ethanolic leaf extracts of Gongronema latifolium. The zones of inhibition were concentration dependent, ranging from 2.0mm to 10.8mm for aqueous extract and 2.0mm to 8.3mm for the ethanolic extract. Comparison of the zones of inhibition produced by the two extracts showed that there is no statistical difference (P > 0.05) between aqueous and ethanolic extracts. Staphylococcus aureus, Escherichia coli and Klebsiella pneumoniae had Minimum inhibitory concentration (MIC) of 6.25mg/mL, while Pseudomonas aeruginosa had MIC of 25mg/mL for the aqueous extract. The MIC was 3.125mg/mL, 6.25mg/mL, 6.25mg/mL and 25mg/mL for S. aureus, E. coli, K. pneumoniae and P. aeruginosa, respectively for the ethanolic extract. Gongronema latifolium extracts were also bactericidal in action. S. aureus, E. coli and P. aeruginosa all had Minimum bactericidal concentration (MBC) of 6.25mg/mL, while K. pneumoniae had MBC of 25mg/mL for the aqueous extract, while for the ethanolic extract, S. aureus, E. coli, K. pneumoniae and P. aeruginosa had MBC of 12.5mg/mL, 12.5mg/mL, 6.25mg/mL and 3.125mg/mL respectively. The data obtained from the study indicated that both the aqueous and ethanolic leaf extracts of Gongronema latifolium possess antibacterial properties. Therefore, the pharmaceutical industries should consider its usage for the production of novel antibiotics.

Keywords: : Antibiotic, Plants, Pseudomonas aeruginosa, Resistance, medicinal

Interrogating Foucauldian Concept of Power/Knowledge in Shakespeare’s The Tempest (Published)

This paper is an attempt to discuss the operation of power/knowledge and invisible disciplinary measures that are operational in Shakespeare’s tragi-comedy The Tempest. Prospero’s island in this play can be assumed as a metaphorical presentation of modern society where human behavior is determined by the implication of power/knowledge structure. The play validates Michel Foucault’s claim for omnipotent nature of Power being operated through the manipulations of Knowledge. Power and knowledge are inseparable and in order to make an effective society, modern institutions ceaselessly produce knowledge leading to “biopower”. These are the basic tenets of Michel Foucault’s conception of power/knowledge. Besides the theme of power, this play can also be analyzed basing on power relations and production of knowledge in both the court and exiled life. We have tried to analyze Shakespeare’s theme of power in The Tempest in the light of Foucault’s concepts and explore human relations based on the integrity of power/knowledge. However, the paper also shows the reversal of power relations in the form of resistance from the apparently docile and controlled bodies. 


Keywords: Biopower, Disciplinary power, Panopticon, Power/knowledge, Resistance