The microbial composition of the frass from maize (Zea mays) grains and seven dried root and tuber crops (R&TC) infested by Prostephanus truncatus were evaluated. Five cubes (6 cm 3 ) of each R&TC as well as 100 g of maize grains were separately infested with 15 pairs of 1-2 day old adult LGB in 250 cm 3 sized Kilner jars and incubated for 90 days at 28 + 18C and 79-82% RH. At 90 days post-infestation, the microbiological assay of frass from the commodities was performed. The results indicated the presence of 10 bacterial species, namely Bacillus cereus, B. macerans, Proteus mirabilis, P. morganic, P. rettgeri, Proteus sp., Pseud geniculatum, Pseud fragii, Pseud putela, Serratia marcences and six fungal species, namely Aspergillus niger, A. tamari, A. parasiticus, A. ochraceus, Fusarium compacticum and F. oxysporum. Infested cubes of M. esculenta have the highest population of adult LGB (168.3) and frass from its damaged cubes had the highest mean bacterial count of 30.0 6 10 7 colony forming units (CFU) and it was significantly (P 5 0.05) higher than LGB infestation and bacterial infection of other R&TC. The bacterial count from the damaged commodities correlated positively and significantly (P 5 0.05) with weight of frass, percentage damage and percentage weight loss. The results revealed that frass from the LGB-infested and damaged commodities were infected by bacteria and fungi. Maize grains and dried R&TC should therefore be protected from LGB infestation to avoid quantity reduction and microbial infection.

Effects of 2,4-D(2,4-dichlorophenoxy acetic acid) and Dichlorvos(2,2-dichlorovinyl dimenthyl phosphate DDVP) were investigated on soil microbial population in a 4 weeks experiment. Soil samples were serially diluted and inoculated using pour plate method on different medium and incubated at 37°C for 24 and 48 hrs for enumeration of microbial diversity, colonies that appeared on plates were counted. At pre-application of 2,4-D, bacteria had the highest population (9.5x107 Cfu), followed by fungi (7.5x105 Cfu ), actinomycetes (1.6x106 Cfu) and protozoa (1.1x103 Cfu). Likewise, the pre-application of DDVP represents the population count of microorganisms in the following manner: Bacteria (8.0x107 Cfu)>fungi (5.1x105 Cfu)>actinomycetes (1.0x106 Cfu)> protozoa (1.0x103 Cfu)f The post-application of 2,4-D and DDVP also had the similar pattern of population count. With percentage difference on each of the microbial counts, 2,4-D of bacteria, fungi, actinomycetes and protozoa (99.5%, 95.3%, 99.9% and 86.0% respectively), DDVP percentage difference (99.2%, 99.4%, 99.3% and 98.6% respectively). Application of these pesticides at recommended rates was followed by the general decline in microbial counts. Therefore, the pesticides had toxic effects on microorganisms which may be beneficial to cultivated plants.

Aframomum species (Aframomum danielli, Aframomum melegueta and Aframomum sceptrum) are used traditionally as medicine and food preservatives. Synthetic preservatives have been reported to be carcinogenic; hence, the continuous search for a natural preservative. This study was designed to validate the efficacy of the three named Aframomum species as a preservative against fungi that causes spoilage in raw fish and meat. The methanolic extracts of the samples were screened against Aspergillus tamarii, Aspergillus fumigatus, Aspergillus ochraceus and Trichoderma sp. using pour plate technique. The fungi were isolated from the raw fish and meat by the method of serial dilution then pour plated into Potatoes Dextro Agar (PDA) incubated at 37ºC for 7 days. The fungi observed were subcultured to get pure culture. The three samples showed significant antifungal activities against Aspergillus tamarii, Aspergillus fumigatus, Aspergillus ochraceus and Trichoderma sp. at 25%, 50% and 75% concentrations. The significant antifungal activities displayed by extract of these samples could be attributed to their phytochemical and nutritional components of the samples as well as their antioxidant activity. The three samples could be valuable natural preservatives with additional therapeutic potential.

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