3

Populations of the spiraling whitefly, Aleurodicus dispersus Russell (Homoptera: Aleyrodidae), were monitored on cassava plants in five sites in Benin City, Nigeria from February, 1999 to January, 2001 (24 months). The study revealed higher abundance of the whitefly on the mature and old leaves than the young ones. Since the distribution followed the same trend on all the sites, analysis of variance test on the data showed that the spatial distribution of whiteflies was not significantly different (P<0.05) from each other at P = 0.05 level. Periods of high population of A.

This paper examines resource use efficiency on small and large farms in Kwara State of Nigeria. Primary data were collected from 120 farmers who were selected using multistage random sampling method. The data were analyzed using descriptive and regression techniques. Results of the analysis revealed that farm size and fertilizer play major role in explaining variations in farm output. The marginal value product (MVP) of land, labour, purchased inputs, durable capital and fertilizer were positive and higher on large farms than on small farms.

The causal organism(s), and percentage infection of thread blight disease observed on some tea stands established in 1985 at the Cocoa Research Institute of Nigeria (CRIN), Ibadan, experimental plot was investigated for a period of one year (12 months). For the first months, the percentage infection ranges between 41.4% and 47.9%. Out of three fungi isolates (Botryodiplodia theobromae, Fusarium sp. and Marasmius pulcher) only M. pulcher produced the characteristic symptom observed in the field.

In most cities in Nigeria, Industrial and Domestic effluents are discharged indiscriminately into the environment. In city slums, the usual practice is for people to live side by side with the waste they produce (both liquid and soilid waste) thereby leaving them at the mercy of diseases. In highbrow areas of cities, wastes may be properly drained but channeled into streams, rivers and lakes with the resultant damage to aquatic flora and fauna. Industrial effluents are usually of channeled into water bodies and the cost in terms of fish kills is enormous.

The modulatory effects of three dietary supplements, honey, garlic (Allium sativum L.) and bitter kola (Garcinia kola seed) on sodium arsenite-induced toxicity were evaluated in rabbits. The experimental animals were fed 100 mg/kg body weight each of honey (Ho) and aqueous extracts of garlic (Ga) and bitter kola (Bi) either alone or in combination for five weeks. Sodium arsenite (2.5 mg/kg body weight) was fed at the beginning of the third week while feeding with the dietary supplements continued throughout the period of the experiment. Control rabbits were given distilled water.

A survey of the fungal flora of shelled cotton (Gossypium hirsutum) seeds stored at ambient temperature and how it affects the oil content was carried out using cotton seeds obtained from some local markets in Benin City, Nigeria. Three fungi (Rhizopus spp.; Aspergillus tarmarii and Candida spp.) were isolated from the seeds. Oil loss increased with storage. Rhizopus-inoculated seeds and uninoculated ones were almost equally affected. Oil loss in seeds inoculated concurrently with the three fungi did not differ significantly from the control.

The antibacterial activity of aqueous, ethanolic and methanolic extracts of Ricinus communis were studied by the agar diffusion method. The ethanolic extract produced the greatest antimicrobial activity and the aqueous extract the least. Staphylococcus aureus was the most sensitive to the extracts while Bacteroides fragilis was the most resistant. The minimum bactericidal concentration of the extracts ranged between 60% (w/v) and 100% (w/v). Thus the extracts of Ricinus communis could be useful as a source of antibiotics against aerobic and anaerobic bacteria.

Investigations based on field records and experiences at the Guinea Fowl Production Research Unit of the Kainji Lake Research Institute have shown that some diseases management conditions which include: yolksac, fungal infections, collibacillosis, helminthiasis, management problems in particular inbreeding, moulting, heatstroke and nutritional deficiencies affect significantly the reproductive organs, egg laying and hatchability.

Drinking water sources are epidemiologically suspected as one of the major transmission agents for pathogenic and perhaps drug resistant Enterobacteria. Accordingly, in the period October, 1995 – September, 1996, water samples as were available from tap, borehole, well, dams and rivers in randomly selected 19 Local Government areas of Kano State were screened for these bacteria. 1201 isolates comprising Citrobacter sp. (16.91%); Enterobacter aerogenes (14.99%); Klebsiella sp. (10.24%); Proteus sp. (9.58%); Shigella sp. (9.49%); Escherichia coli (8.24%); Salmonellae (7.99%) and Vibrio sp.

Mosquito coils (bars), formulated from three plant leaves, namely; Acalypha torta, Carica papaya and Calotropis gigantica, and seeds of Peganum harmala, were tested as repellents or toxicants against laboratory reared Culex sp. adult mosquitoes when burnt as an incense. None of the plants showed toxic activity, as knockdown was less than 5% in all cases. Slight repellency was observed with Acalypha sp. (0.21) and P. harmala (0.19), as these showed significant difference (P < 0.05) from values recorded for the control, i.e. bars without plant material.