Natural multiple viral infections of cultivated cowpeas have been reported in Nigeria. In this study, three Nigerian commercial cowpea cultivars ("Olo 11", "Oloyin" and "White") and two lines from the IITA (IT86D-719 and TVU 76) were mechanically inoculated with Cowpea aphid-borne mosaic virus (CABMV), Bean southern mosaic virus (SBMV) and Cowpea mottle virus (CMeV) singly, as well as in all possible combinations at 10, 20 and 30 days after planting (DAP). Samples of leaves or stems were collected at 10, 20 and 30 days after inoculation (DAI) and analyzed for relative virus concentration by Enzyme-Linked Immunosrbent Assay. All the cultivars and lines {CVS/L} were susceptible to the viruses but the commercial CVS showed more severe symptoms and had relatively higher viral concentration. In single virus infections, CABMV which induced the most severe symptoms had absorbance values (at 405 nm) of 0.11 to 0.46 while SBMV and CMeV which induced moderate symptoms had virus titre of 0.74 to 1.99 and 0.11 to 0.90 respectively. Plants inoculated 10 DAP had significantly higher virus concentration than those inoculated 30 DAP. In mixed infections involving CABMV (10 DAP) apical necrosis and death were observed in commercial cultivars "Olo 11" and "White". Enhancement of CMeV titers were observed in plants infected with CMeV + CABMV. Multiple viral infections of cowpeas may result in complete yield loss, hence, the availability of seeds of cultivars with a high level of multiple virus resistance is recommended as a means of control.

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Ethanol and water extracts of Bridelia ferruginea were examined for antimicrobial properties. The leaf, bark and root extracts, which were tested from initial concentration of 100mg/ml to the final concentration of 6.25mg/ml, produced invitro antimicrobial activities in assays against clinical isolates of Pseudomonas aeruginosa, Klebsiella pneumoniae, Shigella dysentriae, Proteus mirabilis, Staphylococcus aureus, Hemophilus influenzae, Steptococcus pneumoniae and Escherichia coli. The agar well diffusion method was used to determine the antimicrobial properties of the extracts. The results showed that the growths of the organisms were inhibited by both ethanolic and water extracts of B. ferruginea, although the water extracts of plant parts showed significantly lower zones of inhibition. Higher inhibitory effects were seen with the bark and leaf extracts of the plant using ethanol. However, little inhibitory effect was observed in water extracts of the leaves and bark of the plant and no growth was observed with water extract of the root. The minimum inhibitory concentrations (MIC) of the bark extract were 5.5, 10.5, 34.0 and 42.0 for P. aeruginosa, S. pneumoniae, H. influenzae, K. pneumoniae, and P. mirabilis respectively.

Viral diseases constitute obstacles to pepper production in the world. In Nigeria, pepper plants are primarily affected by pepper veinal mottle virus (PVMV), Cucumber mosaic virus (CMV), Pepper leaf curl Virus (TLCV), Tobacco mosaic virus (TMV), Pepper mottle virus (PMV) and a host of other viruses. The experiment was carried out with a diagnostic survey on the experimental field of the National Horticultural Research Institute, Ibadan, Nigeria and on pepper farms in six local government areas within Ibadan Oyo State, Nigeria, forty samples were collected from each of the farms. Diseased samples were obtained from the field and taken to the laboratory for indexing. In ELISA test some of the samples from the pepper farms showed positive reaction to single infection with PVMV (36.79%), CMV (22.14%) while some others showed positive reaction to mixed infection of the two viruses (10%) but some also negative reaction to PVMV and CMV antisera (31.07).

This study was carried out to determine the effects of single infections and co-infections of three unrelated viruses on three cowpea cultivars (one commercial cowpea cultivar “White” and 2 IITA lines; IT81D-985 and TVu 76). The plants were inoculated with Cowpea aphid-borne mosaic virus (CABMV), genus Potyvirus, Cowpea mottle virus (CMeV), genus Carmovirus and Southern bean mosaic virus (SBMV), genus Sobemovirus singly and in mixture (double and triple) at 10, 20, and 30 days after planting (DAP). The treated plants were assessed for susceptibility to the viruses, growth, and yield. In all cases of infection, early inoculation resulted in higher disease severity compared with late infection. The virus treated cowpea plants were relatively shorter than buffer inoculated control plants except the IT81D-985 plants that were taller and produced more foliage. Single infections by CABMV, CMeV, and SBMV led to a complete loss of seeds in the three cowpea cultivars at 10 DAP; only cultivar White produced some seeds at 30 DAP. Double and triple virus infections led to a total loss of seeds in all three cowpea cultivars. None of the virus infected IITA lines produced any seeds except IT81D-985 plants co-infected with CABMV and SBMV at 30 DAP with a reduction of 80%. Overall, the commercial cultivar “White” was the least susceptible to the virus treatments and produced the most yield (flowers, pods, and seeds). CABMV was the most aggressive of these viruses and early single inoculations with this virus resulted in the premature death of some of the seedlings. The presence of the Potyvirus, CABMV in the double virus infections did not appear to increase disease severity or yield loss. There was no strong evidence for synergistic interactions between the viruses in the double virus mixtures.

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This study investigated the effect of inoculating three Amaranthus hybridus cultivars: NHAM/114, NH84/457-IL and LOCAL GREEN cultivar with Amaranthus mosaic virus (AMV) consecutively for four weeks. Results indicated significant differences between the control and virus inoculated plants. Severity of infection by the virus was more pronounced in plants inoculated at early ages while the effect was very mild on plants inoculated at later stage of growth. Reduced weight values were recorded in plants with early infection compared to plants inoculated at later stages of growth. Mean values of 0.190, 0.250 and 0.218 g were obtained for fresh weights of leaves of NHAM/114, NH84/457-IL and LOCAL GREEN respectively at 2 weeks after planting (WAP) while plants that were inoculated at 5 WAP had average values of 0.516, 0.392 and 0.397 g fresh weights of leaves for the three cultivars respectively. The percentage decrease in fresh weight of stem of the LOCAL GREEN cultivar was above average (56%) and higher than those of NHAM/114 and NH84/457-IL. NHAM/114 produced the least dry weights in stem while the highest dry weights were recorded for NH84/457-IL at all the stages of inoculations. These results indicated that infection at an early age resulted in greater reduction of the parameters assessed.