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Stalk and ear rot is one of the most common fungal disease of maize. Significant crop failure and yield loss, arising from the disease, are reported annually. Maize grains infected with the pathogen pose serious threat to human and animal health, owing to mycotoxins contamination. The present study evaluated aqueous extracts from Allium sativum in the management of the disease. Four concentrations of the extracts were evaluated against the pathogen in vitro. The most promising concentrations, were applied as seed dressing agents in vivo at 5, 10 and 15-minutes duration for each concentration. Garlic extracts-dressed seeds were then transferred to F. verticilliodes infested medium and allowed to germinate and grow for 9 days. Seedlings were transplanted into sterile soils in plastic buckets thereafter. Data collected were subjected to analysis of variance and mean separation. The results obtained showed that peak inhibition of mycelial growth was achieved by 80% garlic extract concentration (76.29% at three days after inoculation). The in vivo study showed that the concentration of garlic extracts as well as the duration of treatment had significant effect on seed germination. Maize seeds dressed with 80% aqueous garlic extract had the least percentage germination, 43.33%, but recorded the least disease incidence and severity at 2 weeks after transplanting. It also had the best yield, fresh weight of cobs, 303.86 g, and the least percentage of kernel infection with F. verticillioides, 15.00%. Garlic extract has potential, as a bio-fungicide, in the management of stalk and ear rot disease of maize.

The adverse effect of the living components of the environment on plants is called biotic stress. Food insecurity, environmental degradation and global warming are some of the problems associated with loss of vegetation cover and crops death resulting from the activities of insect pests and pathogenic organisms (biotic stressors). A number of control measures exist for the management of plant biotic stress, but chemical control measures appear to be the most common in several parts of the globe. Mammalian toxicity, carcinogenicity, mutagenicity and disruption of the natural ecosystem are some of the common problems associated with chemical control of biotic stressors. It has therefore become imperative to adopt other management strategies that are environment friendly and less toxic to man and nontarget organisms. Botanicals and antagonistic fungi are two of these alternatives. They are cost effective, safe, environment friendly and sustainable. The tropic, because of its peculiar geography, ecology and economy, will benefit from this approach immensely.

The virulence and adhesive properties of 50 isolates of Candida albicans serotypes A and B collected over 6 years from 48 paediatric burn patients were examined to provide more detailed information about candidal pathogenesis in burn patients and to examine the relevance of the commonly used epithelial cell adhesion assay for determining fungal virulence. The isolates represented a fair distribution of serotypes (29 isolates were serotype A and 21 isolates were serotype B) and a total of 28 serotype-biotype combinations were found; 32% of the serotype-biotype combinations appeared only once, while 44% of the isolates showed similar biotype tests for two of three digits. Adhesion of the isolates to plastic and to buccal epithelial cells (BECs) was examined and compared after growth in a chemically defined medium. There were significant differences in the adhesion of individual isolates to plastic or BECs, but no correlation was found between biotype and adhesiveness. Serotype B isolates were found to be more adhesive to BECs (p less than 0.05) but not to plastic. There was no apparent correlation between candidal adhesiveness and site of isolation from these patients (autografts, blood, faeces, throat swabs, tracheal aspirates, wounds and intravenous catheters), although isolates from catheters were generally less adhesive to epithelial cells. Virulence in a systemic infection mouse model revealed that there were significant differences in virulence between isolates, but no correlation was found between virulence and the biotype, serotype or site of isolation. Similarly, no correlation was found between virulence and adhesiveness or cell-surface hydrophobicity.(ABSTRACT TRUNCATED AT 250 WORDS)