OS Balogun

Bio: OS Balogun is an academic researcher from University of Ilorin. The author has contributed to research in topics: Cucumber mosaic virus & Mosaic virus. The author has an hindex of 8, co-authored 21 publications receiving 150 citations.

Occurrence and distribution of pepper veinal mottle virus and cucumber mosaic virus in pepper in Ibadan, Nigeria

Abstract: 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).

Pathogenicity and cell wall-degrading enzyme activities of some fungal isolates from cowpea (Vigna unguiculata (L) Walp)

Abstract: Nine fungal species isolated from cowpea seeds were used as inocula on four cowpea varieties commonly distributed to farmers in Ilorin, Kwara state, Nigeria by the National Seed Service, a subsidiary of the Federal Ministry of Agriculture and Natural Resources. The effects of fungi on germinability and seedling health were determined using seedling symptom test. Two of the virulent species were screened for the production of cell wall degrading enzymes using viscometric method. All the fungi reduced germination rate in all the cowpea varieties and different types of seedling symptoms were noted for the fungi. The symptoms included seed rot, chlorotic leaf development, stunted growth etc. Production of pectinases and cellulases by Aspergillus flavus and Penicillum sp. was observed and the virulence of the two organisms could be attributed to the activities of these cell wall degrading enzymes.

Time-course analysis of the accumulation of phenols in tomato seedlings infected with Potato Virus X and Tobacco mosaic virus

Abstract: The cotyledons of 3 –true leaf potted seedlings of a common Japanese tomato (i.e. cv. Fukuju No. 2) were mock inoculated with buffer only or singly and doubly with potato Virus X (PVX) and/or an attenuated strain (L11A) of tobacco mosaic virus (TMV-L11A) in greenhouse experiments. Time-course analysis of the methanol-extractable free, and saponifiable ester-bound phenol contents, as determined by the Folin-Ciolcalteau method, showed significantly higher accumulation in the primary leaves during the first 3 days in both mock and viral inoculated plants compared to the uninoculated controls. Whereas, however, the level in the healthy plants remained at about the same level thereafter, that in the infected plants continued to increase steadily peaking between 6 and 10 days postinoculation (dpi). Single infection induced significantly more free phenol accumulation than mixed infection at the peak period. The mean daily level of ester- bound cell wall phenols was about 12 – 20 times lower than that of the free phenols. It increased steadily in infected plants doubling its initial concentration as at 12 dpi but remained relatively unchanged in the healthy plants in the course of development. In contrast to the trend for methanol extractable free phenol accumulation, mixed infected plants had higher contents of saponifiable phenols than singly infected ones. Thin layer chromatography on silica gel G of the extracts from samples obtained at 12 dpi revealed at least 5 distinct bands (spots) that were common to both healthy and infected plants. However, the appearance of some extra bands that were highly florescent under long wave (320 nm) ultraviolet light on non florescent background silica gel, also indicating their phenolic nature, were limited to infected plants only. This indicates that viral infection not only affected the quantity but may also have altered the type of phenol components of the infected tomato plants. Key Words: Tomato cv. Fukuju No. 2, mock and viral inoculations, phenolic components Biokemistri Vol.16(2) 2004: 112-120

Survey of the symptoms and viruses associated with cowpea (Vigna unguiculata (L.)) in the agroecological zones of Kwara State, Nigeria

Abstract: A comprehensive field survey was carried out in 2011 spanning thirty locations within the forest and savannah agroecologies of Kwara State, Nigeria. This was with the objective of having an overview of the prevalence of virus disease symptoms and to specifically identify the viruses infecting cowpea ( Vigna unguiculata .L.) in Kwara State. Data were collected on the prevalence of some peculiar virus symptoms on cowpea plants on growing on farms in each location. Symptomatic cowpea leaves were also collected from each location for virus identification in the laboratory. The serological protocol employed for virus detection in the leaf samples was the antigen – coated plate Enzyme linked immunosorbent assay (ACP–ELISA) method. The results of the field survey indicated that the symptoms observed on the cowpea plants were peculiar to those associated with virus disease infection. The symptoms observed were leaf mottling (36.8%), mosaic (24.9%), leaf curl (15.6%), necrotic spots (8.2%) and other symptoms (14.5%). The result of the laboratory assay to detect the viruses present in the leaf samples revealed the presence of four (4) different viruses. The viruses identified were, Cowpea Aphid Borne Mosaic Virus (CABMV), Cowpea Yellow Mosaic Virus (CYMV), Blackeye Cowpea Mosaic Virus (BICMV) and Cowpea Mottle Virus (CPMoV). These viruses were detected infecting the cowpea plants in mixtures of two or three. These results are indicative of the presence of viruses in all the ecological zones of Kwara State where cowpea is cultivated. Keywords : Survey, Agroecology, Cowpea, Virus, Symptoms, ACP-ELISA

Assessment of the effect of rate and time of application of rice-husk powder as an organic amendment on cowpea (Vigna unguiculata L.,walp) inoculated with cowpea mottle virus

Abstract: A Screen house experiment using potted plants was carried out to assess the effects of time and rate of application of Rice-husk powder as an organic amendment on cowpea (Vigna unguiculata L Walp) cv. Ife Bimpe, that were mechanically inoculated with Cowpea Mottle Virus (CMeV). The results showed that the organic amendment was very effective on plants with soils amended with rice-husk powder, as the plants exhibited better yields and productivity. The amended plants also showed considerable less susceptibility to the virus pathogen compared to the non-amended plants. The results of the experiment further showed that the rate and time of application of the Rice-husk powder was a key factor in the ameliorative effect of this organic amendment in the suppression of the viral inoculum. An application rate of 0.50kg of Rice-husk powder per 10kg of soil two weeks before sowing the cowpea seeds was observed to confer on the plants the highest growth and yield attributes and also the least susceptibility to Cowpea Mottle Virus (CMeV). On the other hand, cowpea sown on soils amended at a lower rate of 0.125kg of Rice-husk powder per 10kg of soil two weeks after planting were found to have higher susceptibility to Cowpea Mottle Virus (CMeV). This is indicative that Rice-husk which is cheap, readily available and environmentally friendly offers a promising prospect in Agriculture both as an Organic amendment and in the control of virus disease in Cowpea if applied at recommended rates and time.

Chilli Anthracnose: The Epidemiology and Management.

Abstract: Indian cuisine is renowned and celebrated throughout the world for its spicy treat to the tongue. The flavor and aroma of the food generated due to the use of spices creates an indelible experience. Among the commonly utilized spices to stimulate the taste buds in Indian food, whole or powdered chilli constitutes an inevitable position. Besides being a vital ingredient of of Indian food, chilli occupy an important position as an economic commodity, a major share in Indian economy. Chilli also has uncountable benefits to human health. Fresh green chilli fruits contain more Vitamin C than found in citrus fruits, while red chilli fruits have more Vitamin A content than as found in carrots. The active component of the spice, Capsaicin possesses the antioxidant, anti-mutagenic, anti-carcinogenic and immunosuppressive activities having ability to inhibit bacterial growth and platelet aggregation. Though introduced by the Portuguese in the Seventeenth century, India has been one of the major producers and exporters of this crop. During 2010-2011, India was the leading exporter and producer of chilli in the world, but recently due to a decline in chilli production, it stands at third position in terms of its production. The decline in chilli production has been attributed to the diseases linked with crop like anthracnose or fruit rot causing the major share of crop loss. The disease causes severe damage to both mature fruits in the field as well as during their storage under favorable conditions, which amplifies the loss in yield and overall production of the crop. This review gives an account of the loss in production and yield procured in chili cultivation due to anthracnose disease in Indian sub-continent, with emphasis given to the sustainable management strategies against the conventionally recommended control for the disease. Also, the review highlights the various pathogenic species of Colletotrichum spp, the causal agent of the disease, associated with the host crop in the country. The information in the review will prove of immense importance for the groups targeting the problem, for giving a collective information on various aspects of the epidemiology and management of the disease.

Improving Seed Health and Seed Performance by Positive Selection in Three Kenyan Potato Varieties

Abstract: Selecting seed potatoes from healthy-looking mother plants (positive selection) was compared with common Kenyan farmer practice of selection from the harvested bulk of potatoes (farmer selection) in 23 farmer-managed trials. Positive selection assured lower incidences of PLRV (39%), PVY (35%) and PVX (35%). Positive selection out-yielded farmer selection irrespective of the agro-ecology, crop management, soil fertility, variety and quality of the starter seed, with an overall average of 30%. Regression analysis showed a relation between lower virus incidence and higher yield for the varieties. The paper discusses the consequences for seed system management in African countries. Furthermore possible additional effects of positive selection are discussed and further research is suggested. The paper concludes that positive selection can benefit all smallholder potato producers who at some stage select seed potatoes from their own fields, and should thus be incorporated routinely in agricultural extension efforts.

Prediction of irrigation groundwater quality parameters using ANN, LSTM, and MLR models

Abstract: Forecasting the irrigation groundwater parameters helps plan irrigation water and crop, and it is commonly expensive because it needs various parameters, mainly in developing nations. Therefore, the present research’s core objective is to create accurate and reliable machine learning models for irrigation parameters. To accomplish this determination, three machine learning (ML) models, viz. long short-term memory (LSTM), multi-linear regression (MLR), and artificial neural network (ANN), have been trained. It is validated with mean squared error (MSE) and correlation coefficients (r), root mean square error (RMSE), and mean absolute error (MAE). These machine learning models have been used and applied for predicating the six irrigation water quality parameters such as sodium absorption ratio (SAR), percentage of sodium (%Na), residual sodium carbonate (RSC), magnesium hazard (MH), Permeability Index (PI), and Kelly ratio (KR). Therefore, the two scenario performances of ANN, LSTM, and MLR have been developed for each model to predict irrigation water quality parameters. The first and second scenario performance was created based on all and second reduction input variables. The ANN, LSTM, and MLR models have discovered that excluding for ANN and MLR models shows high accuracy in first and second scenario models, respectively. These model’s accuracy was checked based on the mean squared error (MSE), correlation coefficients (r), and root mean square error (RMSE) for training and testing processes serially. The RSC values are highly accurate predicated values using ANN and MLR models. As a result, machine learning models may improve irrigation water quality parameters, and such types of results are essential to farmers and crop planning in various irrigation processes.

Comparative Proteomic Analysis of Different Isolates of Fusarium oxysporum f.sp. lycopersici to Exploit the Differentially Expressed Proteins Responsible for Virulence on Tomato Plants.

Abstract: The vascular wilt of tomato caused by Fusarium oxysporum f.sp. lycopersici is an important soil borne pathogen causes severe yield loss. The molecular characterization and their interaction with its host is necessary to develop a protection strategy. 20 isolates of F. oxysporum f.sp. lycopersici (FOL) were isolated from wilt infected tomato plants across Tamil Nadu. They were subjected to cultural, morphological, molecular and virulence studies. The results revealed that all the isolates produced both micro and macro conidia with different size, number of cells. The colors of the culture and growth pattern were also varied. In addition, chlamydospores were observed terminally and intercalary. The PCR analysis with F. oxysporum species-specific primer significantly amplified an amplicon of 600 bp fragment in all the isolates. Based on the above characters and pathogenicity, isolate FOL-8 was considered as virulent and FOL-20 was considered as least virulent. Proteomics strategy was adopted to determine the virulence factors between the isolates of FOL-8 and FOL-20. The 2D analyses have showed the differential expression of 17 different proteins. Among them, three proteins were down regulated and 14 proteins were significantly up regulated in FOL-8 than FOL-20 isolate. Among the 17 proteins, 10 distinct spots were analyzed by MALDI-TOF. The functions of the analyzed proteins, suggested that they were involved in pathogenicity, symptom expression and disease development, sporulation, growth, and higher penetration rate on tomato root tissue. Overall, these experiments proves the role of proteome in pathogenicity of F. oxysporum f.sp. lycopersici in tomato and unravels the mechanism behinds the virulence of the pathogen in causing wilt disease.