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

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

Effects of a Carbendazim-Mancozeb Fungicidal Mixture on Soil Microbial Populations and Some Enzyme Activities in Soil

The effects of a Carbendazim-Mancozeb fungicidal mixture on microbial populations and some enzyme activities of three selected soils of Kwara State, Nigeria were studied. The soil dilution method was used to isolate bacteria, fungi, actinomycetes and some functional microbial groups from treated soils. Cultivation and enumeration of the soil microorganisms were made on different selective media. Assays for cellulases and pectinases in the treated soils were carried out. The populations of actinomycetes,bacteria and fungi were reduced significantly by the application of the fungicide. The fungicide applied at a concentration of 2.34mg/kg soil had a greater (p < 0.05) inhibitory effect than the recommended concentration of 1.67mg/kg soil. The populations of nitrogen fixers nitrifying bacteria and cellulolytic organisms were also significantly (p < 0.05.) reduced at the two concentrations. The fungicidal mixture equally lowered the cellulose and pectinase enzyme activities in soil significantly, with a return to normalcy by 60 days after treatment. A re-establishment of the soil microbial populations was observed by 21 days after treatment. It was concluded that the use of the Carbendazim-Mancozeb mixture should be with caution since it reduced the populations of ecologically important non-target organisms and that the recommended concentration should be adhered to

Incidence and Severity of Common Viral and Fungal Diseases of Dry Season Tomato Crop in a Southern Guinea Savannah Agro-Ecology

The incidence and severity of common fungal and viral diseases affecting dry season tomato crop were determined on the tomato field of the Teaching and Research farm of the University of Ilorin, situated in the Southern Guinea savannah ecological zone of Nigeria. Seeds were sown in January in the nursery and seedlings were transplanted to the field, inJanuary 2005 and 2006 at the age of 4 weeks. The growth period of tomato was partitioned into three stages viz: seedling/vegetative stage (1), pre-flowering stage (2), and flowering/fruiting stage (3), during which the incidence of fungal, viral or mixed fungal and viral diseases wereinvestigated. The aim was to identify the relative prevalence of the disease categories for each growth stages. The results showed plants in the earliest stage of growth with the lowest rate of infection. Nevertheless, viral disease incidence was the significantly highest (22.7%) at this stage. The incidence of double infections increased gradually from the second growth stagereaching 29% in the third stage. Comparatively, infection with virus alone in the third stage was 28.5%, while fungus alone was 0. 59%. The highest disease severity was in plants that were mixed infected by the two categories of pathogens. Such plants had significant retardation ofgrowth (height and mean number of leaves/ leaflets) and yield attributes such as the number of fruits produced per plant compared to singly infected and apparently healthy plants.Keywords: Disease incidence, dry season, tomato, Southern Guinea savannah ecology

Rural-Urban Differences in Maternal Responses to Childhood Fever in South East Nigeria

Childhood fevers due to malaria remain a major cause of morbidity and mortality among under-five children in Nigeria. The degree of vulnerability perceived by mothers will affect their perception of the severity and threat of their child's fever and the patterns of health care use. This study was undertaken to compare maternal responses to childhood fever in urban and rural areas of Enugu, south east Nigeria.Data was collected with pre-tested interviewer-administered questionnaires from 276 and 124 urban and rural households respectively. In each household, only one woman aged 15-49 years who had lived in each of the urban and rural communities for at least one year and had at least one child less than 5 years old was interviewed. Malaria was mentioned as the commonest cause of childhood fevers. Rural mothers were more likely to recognize danger signs and symptoms than urban mothers. Rural mothers use more of informal than formal health services, and there is more home management of the fever with urban than rural mothers. Chloroquine, ACT, SP and Paracetamol are the main drugs given at home for childhood fevers, but the rural mothers were more likely to use leftover drugs from previous treatment to treat the fevers than urban mothers. The urban respondents were also more likely to use a preventive measure. Urban mothers sought actions faster than rural mothers and the total cost of treatment was also higher in urban areas.Both urban and rural mothers are aware that malaria is the major cause of childhood fevers. Although rural mothers recognize childhood fever and danger signs better than urban mothers, the urban mothers' responses to fever seem to be better than that for rural mothers. These responses and differences may be important for geographical targeting by policy makers for malaria interventions

Studies on effects of benomyl (Benzimidazole) on non-target microflora of a tomato cropped soil

The effect of benomyl on the microflora of a tomato cropped soil was investigated. Benomyl applied as soil  treatments in micro pots at 25 ppm. 50ppm. 75ppm. I00ppm and l 25ppm levels lowered fungal counts while there  was a corresponding increase in total bacterial count with increasing benomyl concentration. Studies were also  conducted to observe the etlect of varying concentrations of benomyl on the population of Pseudomonas species in  tomato soil. Pseudomonas counts decreased with increasing concentration of benomyl both in culture and soil treatments. lt was concluded that the use of benomyl in cuitivation of tomato may not predispose the crop to  Pseudomonad infections.Keywords: Benomyl, non-target microflora, tomato soil

Distribution of fungi and bacteria in the soils of the University of Ilorin Teaching and Research Farm

The occurrence of fungi and bacteria in Afon, Tanke, Badi, Bolorunduro and Ilemona soils of the University of Ilorin Teaching and Research Farm and the impact of some physicochemical properties of the soils on distribution of microorganisms were studied. The soil dilution technique was used to isolate bacteria and fungi on Nutrient Agar and Potato Dextrose Agar Plates respectively. Cultural and microscopic characteristics were employed in the identification of isolates. The population density of fungi in the soils was in the order Afon > Ilemona > Tanke > Bolorunduro > Badi series while that of bacteria was in the order of Afon > Tanke > Bolorunduro > Badi > Ilemona series. The high microbial load of Afon series was attributed to a combination of factors such as its relatively high organic matter content (0.20%) and Effective Cation Exchange Capacity (9.93), the sandy loam texture and the pH (5.7). A variety of fungal and bacterial species associated with nitrogen fixation and organic matter decomposition were isolated from all the soils. The mycoflora of Ilemona soil was dominated by saprophytic Aspergillus spp while plant pathogenic moulds such as Colletotrichum and Fusarium species occurred frequently in the other soils. The frequency of occurrence of Colletotrichum sp in Afon was 52%, while Fusarium spp was 87% in Badi, 36% in Tanke and 5% in Bolorunduro. The occurrence of enteric bacteria in high numbers in Bolorunduro and Ilemona soils was attributed to the presence of grazing cattle in the farmlands. It was concluded that for optimum crop yield, Afon, Badi, Tanke and Bolorunduro soils need to be treated with appropriate fungicides before the cultivation of crops. JARD Vol. 4 (2) 2005: pp. 218-22

Evaluation of the pathogenic effect of some fungal isolates on fruits and seedlings of pepper (Capsicum spp)

Laboratory and screenhouse experiments were carried out to identify and establish the pathogenic status of the micro-organisms isolated from the diseased fruits, stems and leaves of naturally infected pepper plants (Capsicum spp) on a devastated field cropped to assorted vegetables during the latter part of the rainy season of 2003 in Ilorin, Nigeria. Pure cultures of several fungal species were isolated on Potato Dextrose Agar (PDA). The consistently isolated fungi from the fruits and seeds were identified as Penicillium digitatum, Aspergillus flavus and Aspergillus niger while a specie of Verticillium was isolated from the leaves and stems. Pathogenicity tests on fresh pepper fruits in –vitro revealed that all the fungal isolates were pathogenic on the two pepper species (Capsicum annuum and C. frutescens) tested in this study. Level of susceptibility and or virulence however differed as measured in the ability of the fruit to support the growth of the fungi and subsequent development of fruit rot. Penicillium digitatum was the least virulent while Aspergillus niger was the most virulent. Pathogenicity test in the screenhouse showed that foliar inoculation of Verticillium sp on four -week old pepper seedlings induced strong symptom response in the form of initial necrotic spots on the leaves and then eventual wilting and dying -off of the seedlings after 4 weeks of inoculation. No fruits were produced on such diseased plants compared to the mock-inoculated control plants. The three other fungi isolates did not induce any visible infection on the seedlings indicating that the Verticillium sp was responsible for the wilting and drying off observed on the field pepper plants. Keywords: Aspergillus niger, A. flavus, Penicillium digitatum, Verticillium spp, Capsicum annuum, and C. frutescens, fruit rot and wilting.JARD Vol. 4 (2) 2005: pp. 159-16

The Use of Parkia Husk and Melon Wastes as Soil Amendments

A pot experiment was conducted to assess the effects of amending soil with agricultural wastes (Parkia biglobosa (Locust bean) husk (PAH), melon (Citrulus vulgaris) waste (MEW) and their mixture (PAH + MEW)) on some soil physical and chemical properties. The agricultural wastes were applied at two levels (7.5% and 10% w/w agricultural waste/soil) in a randomized complete block design. Changes in soil properties (bulk density, water holding capacity, organic carbon and available phosphorus contents) were observed over a period of 12 weeks. The available phosphorus (P) content of the soil was significantly increased (

Development and Evaluation of Coatings from Cactus opuntia in Prolonging the Shelf-life of Mangoes (Mangifera indica) Stored under Evaporative Coolant System (ECS)

Two different coatings were developed from the mucilage of Cactus and their effects were investigated on the quality and storability of mango fruits. The two experimental coatings were: Pure mucilage extracts (ME) and Mucilage extract mixed with 5ml glycerol (MEG) which served asplasticizer. The following parameters were measured : Weight loss, ascorbic acid content, pH, firmness and microbial qualities. Four hundred and eighty (480) mango fruits of “Ogbomosho” variety were stored for seven weeks at an average temperature of 27±2°C and relative humidity55- 60% under Evaporative Coolant System(ECS) . Prior to storage, the mango samples were surface sterilized using 100mg/-1 sodium hypochlorite and arranged randomly into three treatments, thecontrol (untreated) and two coating treatments. The overall result showed that Cactus mucilage is effective in extending the shelf-life of mango fruits when compared to untreated in the order, MEG>ME>Control. Result revealed that coating hindered the growth of microorganismssignificantly (P<0.05)

Postharvest quality and safety maintenance of the physical properties of Daucus carota L. fruits by Neem oil and Moringa oil treatment: A new edible coatings

Biodegradable edible coatings from Moringa oil(MO) and Neem oil (NO) was applied to carrot fruits in order to provide environmentally friendly, healthy treatments (with which to better preserve fresh fruit quality) and safety during postharvest storage at ambient temperature of 27± 3oC and relative humidity of 50-60% . Physical properties like weight loss and texture were determined throughout the storage period of 6 weeks. The coatings had a significant effect on the development of quality variables.The overall results showed the superiority of the coatings in extending the shelf-life of carrot fruit as compared to controlin the following order Moringa Oil>Neem Oil>Control.Keywords: Edible Coatings, Moringa Oil, Neem Oil, Carrot, Firmness and Weight Loss