Season In Nigeria Research Articles

Response of maize and cucumber intercrop to soil moisture control through irrigation and mulching during the dry season in Nigeria

Replicate field plots were used in experiments aimed at evaluating the yield potentials of maize and cucumber intercrop resulting from the control of soil moisture through irrigation and mulching, for a period of eleven weeks. Three irrigation depths, 2.5, 3.5 and 4.5 mm; and two mulch levels, zero mulch and 10 ton/ha of oil palm bunch refuse as mulch material were employed, while the third option involved the combination of the different levels of irrigation and mulching. These were used alongside fertilizer application. The pertinent growth and yield parameters were then determined. Results of the analysis indicated that there were no significant differences in growth parameters such as plant height, vine length and days to 50% flowering across the treatment variants. Yield components such as total grain yield, total fresh cob yield and total fruit yield differed greatly across the treatment options and also indicated significance at the 1% probability level. It was observed that cucumber total fruit yield was greater in the plots that received only mulching than the other plots. The results of the study highlight the position that the best crop yields would be obtained for maize and cucumber intercrop during the dry season, if farmers resort to optimum application levels while using the synergy of irrigation and mulching to achieve a crop favorable soil moisture regime.

Studies on prevalence of malaria and management practices of the Azia community, Ihiala L.G.A., Anambra State, south-east Nigeria

A prevalence survey of malaria was carried out in Azia, a rural community in Ihiala Local Government Area of Anambra State, southeast Nigeria. Thick blood films of 1000 individuals attending local hospitals in the community were used to determine the prevalence. Also, structured questionnaire was administered to 1000 individuals in order to obtain information on malaria management practices of the people. The study was carried to the wet season in Nigeria. The prevalence rate was found to be 76% and all were infections of Plasmodium falciparum. The prevalence by age was found to be 0-9(13.2%), 10-19(23.2%), 20-29(21.0%), 30-39(13.6%), 40-49(9.7%), 50 and above (19.2%). The malaria management practices showed that 24.6% attend hospitals, 12.0% use traditional medicine from local healers while 25.0% buy antimalarial drugs without prescription by a physician. It was also found that some use more than one method in their management of malaria. Those who combined antimalaria drugs with traditional medicine from local healers were found to be 17.4% combined antimalarials as well as attend hospitals, 13.8% do0 the while 1.2% reported doing nothing about malaria. The Nigerian Journal of Parasitology Vol. 24 2003: 33-38

Lightning signature as an index for the determination of the beginning of the planting season in Nigeria

West African rains are mainly due to the squall-line activities. Squall lines are groups of active thunderstorm clouds that are aligned with the ITCZ in front. The clouds are electrically active and 90% of lightning recorded occurs during squall lines associated thunderstorms. The results of measurements of lightning count from 1986 to date for Nigeria are presented in this work. Data obtained from other West African countries are also compared with them. The maximum lightning count occur mid-way between the north most position to the ITCZ and the ocean; shows a diurnal variation dependent on the movement of ITCZ that has very strong dependence on solar activities via evaporation and wind speed and direction. The minimum count is recorded during the ITCZ's recession and behind it. The applications to agricultural practices in West Africa are discussed. African Journal of Science and Technology Vol. 5(2) 2004: 28-33

Bushmeat trade in Amuro-Okigwe, Nigeria

Types, number and amount of bushmeat displayed for sale in a central bushmeat market in Amuro, Okigwe, Nigeria were recorded for 4 weeks in the month of November, which falls within the dry season in Nigeria. A total of 17 species of bushmeat were identified with the grasscutter, Thryonomis swinderianus , being the most prominent in number (62.8%) and biomass (49.5%). In the 4–week period, a total of 390 animals, weighing 2,602.7 kg and valued at N677,336.00 (approx. USD 5,107.00) were sold. Lunar influence on bushmeat hunting was suspected as fewer animals were caught during the moonlit nights of the month. Comparison of Amuro, Okigwe with other bushmeat hunting grounds, using such indices as human population density and rodent:ungulate ratio, showed that Amuro, Okigwe was likely under a severe hunting pressure. Keywords : bushmeat marketing, cane rats, Thyronomis swinderianus , hunting pressure International Journal of Agriculture and Rural Development Vol. 5 2004: 187-192

Typhoid intestinal perforation in North Central Nigeria

Typhoid intestinal perforation is a surgical problem with severe morbidity and high mortality in North Central Nigeria. In order to determine the pattern and the prognostic indices, we studied 101 patients with typhoid intestinal perforation managed over a ten-year period Children constituted 49% of the cases and majority (78%) of the patients were in the low socio-economic strata. The incidence peaked to 67% between November and March - the dry season in Nigeria. The male/female ratio was 1.9:1 with a mean age of 19 years and a mean hospitalization period of 18 days. There were 167 perforations; four involved the large bowel and appendix, and in 72.2% cases, the perforation was single. The mortality rate was 13.9%, affected mostly children and significantly worsened by prolonged perforation-surgery interval > 72 hours, jaundice, convulsion, ASA V, faecal peritonitis and re-exploration for early intra-peritoneal complications. Morbidity rate was 65.3% and significantly affected more children than adults and associated with perforation-surgery interval of between 24 and 72 hours, haematochezia and multiple perforations. Moribund patients fared better when operated upon under local anaesthesia with adequate analgesia. The least traumatic but effective surgical procedure that could seal the perforations and keep the peritoneum clean gave the best results. Children who survived up to 5 days and adults who survived up to 10 days after surgery had better chances of survival. The most significant prognostic factor is late presentation which prolongs perforation-surgery interval and the other complication and mortality indices are directly influenced by it.

Rainfall and the length of the growing season in Nigeria

AbstractThis study examines the length of the growing season in Nigeria using the daily rainfall data of Ikeja, Ondo, Ilorin, Kaduna and Kano. The data were collected from the archives of the Nigerian Meteorological Services, Oshodi, Lagos. The length of the growing season was determined using the cumulative percentage mean rainfall and daily rainfall probability methods.Although rainfall in Ikeja, Ondo, Ilorin, Kaduna, and Kano appears to commence around the end of the second dekad of March, middle of the third dekad of March, mid April, end of the first dekad of May, and early June respectively, its distribution characteristics at the respective stations remain inadequate for crop germination, establishment, and development till the end of the second dekad of May, early third dekad of May, mid third dekad of May, end of May, and end of the first dekad of July respectively. Also, rainfall at the various stations appears to retreat starting from the early third dekad of October, early third dekad of October, end of the first dekad of October, end of September, and early second dekad of September respectively, but its distribution characteristics only remain adequate for crop development at the respective stations till around the end of the second dekad of October, end of the second dekad of October, middle of the first dekad of October, early October, and middle of the first dekad of September respectively. Thus, the active lengths of the growing season are approximately 5 months, 5 months, 4 months, 4 months, and 2 months respectively. Plants that are short‐dry‐spell tolerant may thrive early in the rainy season, i.e. from the end of the second dekad of March to the end of the second dekad of May (in Ikeja), middle of the third dekad of March to the early third dekad of May (in Ondo), mid April to the middle of the third dekad of May (in Ilorin), end of the first dekad of May to end of May (in Kaduna), and early June to the end of the first dekad in July (in Kano), but other less tolerant plants should be planted starting from the end of the second dekad of May, early third dekad of May, mid third dekad of May, end of May, and end of the first dekad of July respectively. The daily rainfall probability method is recommended as more efficient in the assessment of the nature and length of the growing season. Copyright © 2004 Royal Meteorological Society

Effect of constant temperature and humidity on oviposition and development of Callosobruchus maculatus (F.) and Callosobruchus subinnotatus (Pic) on bambara groundnut, Vigna subterranea (L.) Verdcourt

The effect of different conditions of temperature and humidity on oviposition and development of Callosobruchus maculatus and Callosobruchus s ubinnotatus was investigated in the present study. Four temperatures (25°C, 30°C, 35°C and 40°C) and three humidities (30%, 60% and 90% r.h.) were evaluated on both species in pure and mixed populations on bambara groundnut ( Vigna subterranea) seeds. In both pure and mixed populations, temperature influenced oviposition and progeny development of both species significantly more than humidity. Egg-laying and progeny development in C. maculatus were optimal at 35°C. In contrast, oviposition and progeny development in C. subinnotatus were optimal at 30°C. In mixed populations, where eggs were laid by females of C. maculatus and C. subinnotatus held together, more C. maculatus adults than C. subinnotatus adults were produced at the various temperatures and humidities. No adult progeny of either species developed in pure or mixed populations at 40°C. C. maculatus was more fecund than C. subinnotatus and development from egg to adult took much longer in C. subinnotatus than in C. maculatus in both pure and mixed populations. The implications of these findings for the development and survival of both species in the different agroecologies and seasons in Nigeria are discussed.

Measurement of solar energy radiation at Okigwe using silicon solar cell

Utilizing a silicon solar cell with an average power conversion efficiency of ∼10.23%, the global solar radiation at Okigwe, located at latitude 5° 40′ N and longitude 7° 10′ E, and with no known previous record of such data, was evaluated. Readings were taken hourly and daily for a period of four months, January–April, an important part of the dry season in Nigeria outside the harmattan period. It was observed that the insolation was generally high, reaching up to a monthly mean hourly value of ∼1011.85 W m −2 and has a daily time duration of ∼12 h with ∼8 h of noontime sunlight. The diurnal variation was found to be slight within the months. The monthly mean variation was also found to be slight, varying from 10.22 kW m −2 in January to 9.99 kW m −2 in April.

Modelling the vertical distribution of insects

The Weibull distribution has been used to model the vertical distribution of insects under a number of activities: natural flight without any artificial stimulus, resting behaviour, and response to trapping involving colour attractants and odour baits. Initial approximations of the Weibull parameters are obtained using the least squares method, with more accurate values computed using the maximum likelihood estimates. Coefficients of determination are obtained after linearization of the Weibull equation and results show that these coefficients are generally high, indicating suitability of the model for fitting the observed data. The model yields an analytical formula for determining the mean heights at which the activities tend to occur. The model is tested on data from three sources: coleoptera in natural flight over Tallulah, Louisiana; Glossina palpalis palpalis at rest during the dry season in Nigeria; and catches of Glossina spp., in Rwanda, by traps placed at varying heights above the ground. Results show that different species of insects tend to fly, rest or be trapped at heights which are characteristic of the species.

Effects of sowing date on the growth, yield and quality of okra (Abelmoschus esculentus (L.) Moench.) in southern Nigeria

SUMMARYTwo varieties of okra were sown at approximately 14-day intervals from 1 April to 1 June for 2 years during the main rainy season in Nigeria. Low soil temperature and moisture, which resulted from a combined effect of high solar radiation, high atmospheric temperature and low rainfall, led to poor seedling emergence at the early sowing dates.The growth of the fewer plants of the early sowing dates were more vigorous than those of later sowing dates and they attained 50% flowering earlier and had a longer harvest duration. This resulted in increases in number of pods per plant, pod length, pod diameter, pod volume, pod weight and pod yield per ha, indicating compensatory growth by the fewer plants in the early plantings. The relatively lower values obtained for these variables with the late sowing dates were also attributed to possible poor soil aeration arising from the increased rainfall during their growth period.Sowing dates did not generally affect the percentage moisture, oil and protein in the pods. The effects of varieties on the variables measured were more uniform than those of sowing dates and mostly not significant.

Phytosociological Observations on the Vegetation of Burnt and Unburnt Areas near Ibadan, Nigeria

Phytosociological Observations on the Vegetation of Burnt and Unburnt Areas near Ibadan, Nigeria

Weather hazards in Calabar ? Nigeria

The major weather hazards in Calabar, a coastal town in Nigeria during both winter and summer hemispheres are discussed using meteorological data for 32 years (1951–1982). Results show that during the winter months of November to March, which are usually referred to as the dry season in Nigeria, frequency of occurrence of fog and harmattan dust haze is low. Summer patterns of precipitation are typical of the equatorial zone.

Stomatal Conductance of Two Tropical Trees During the Wet Season in Nigeria

(1) Measurements of stomatal conductance were made on teak and Gmelina on 5 days during the wet season in Nigeria. Both species displayed very high conductances but, when compared in the same conditions, values for Gmelina were less than those in teak. (2) Stomatal conductance was mainly determined by the quantum flux, although the saturation deficit of the air also exerted an effect. (3) Transpiration rates were calculated from the stomatal conductances, using the Penman-Monteith equation. The rates were high, and imply that almost all the net radiation was used to evaporate water. (4) Sensitivity analysis showed that transpiration rate for much of the day is insensitive to changes in the stomatal conductance gs, the aerodynamic conductance ga or the leaf area index. It is however closely coupled to net radiation. (5) The future application of the results to other sites is discussed.

Stomatal Response to Environmental Variables in Two Tropical Forest Species During the Dry Season in Nigeria

SUMMARY (1) Measurements of stomatal conductance using a null-balance diffusion porometer were made on Gmelina and teak on 6 days during the dry season in Nigeria. Stomatal conductance increased rapidly in the early morning and decreased after midday in both species but values in Gmelina were less than those in teak. Leaf water potential, measured with a pressure chamber, was usually lower in Gmelina than in teak. (2) Stomatal conductance in both species was dominantly controlled by irradiance and air saturation deficit and a model, relating stomatal conductance to these two variables accounted for more than 80% of the variation in the measurements. (3) The Penman-Monteith equation was used to calculate transpiration rates from measured stomatal conductances and environmental variables. Transpiration rates using conductances predicted from the model agreed closely with the calculated ones. (4) Hydraulic resistances were similar for both species. (5) The use of these measurements in predicting transpiration rates by the species from weather station data is discussed.

Field reversals during the dry season in Nigeria

The anomalous reversal in the atmospheric potential gradient in northern Nigeria is examined with particular reference to atmospheric moisture content and photoionisation.

The Biology of the Sudan Bollworm, Diparopsis watersi (Roths.), in the Gash Delta, Sudan

Diparopsis watersi (Roths.) is a serious pest of the cotton crop in the Gash Delta of the eastern Sudan. The climate and method of cotton cultivation are described briefly and a general account of the incidence of D. watersi during the season is given. Earlier work in the Sudan on this bollworm was mainly centred in the Northern Province and there is little information on the history of its occurrence in the Gash Delta. The aspects of its biology considered here include its egg-laying and larval habits, and duration of the pupal stage.The majority of eggs were laid on the younger and more accessible plant growth. The period of wandering in search of food after eclosion from the egg was of short duration with normal egg placement, the emerging larvae had little difficulty in finding suitable food, and mortality from failure to do so was low on healthy plants. Depth of pupation did not vary greatly with soil type; the majority of pupae were found within one inch of the soil surface, and none at a depth greater than three inches. Only when the soil was a heavy clay that had baked hard following the rains, did the emerging moths have difficulty in passing through it and ascending to the surface.The proportion of larvae forming diapause pupae increased amongst field-collected larvae as the season advanced, and in successive generations bred in an insectary from the non-diapause fractions of the preceding generations, but at no time was there a complete cessation in the production of non-diapause pupae and infestations persisted as long as there was actively growing cotton. This persistent activity in the Gash Delta is contrasted with the restriction of D. watersi to a six months' season in Nigeria. The emergence of moths from diapause pupae was not completed during the season following that of pupation, but extended for at least two further seasons; approximately 35 per cent, of the total diapause pupal population was still alive and present in the soil after the first season's emergence. In any one season the emergence was bimodal, the two peaks of emergence, which were of similar magnitude, occurring in September-October and mid-November to mid-January. When diapause pupae were kept in the laboratory and thus exposed to less extreme temperatures than in the field, the emergence was distinctly unimodal, with maximum emergence during September. The bimodal emergence observed in the field is considered to be a result of external environmental factors that inhibit pupal development at certain times of year, and emergence data from diapause pupae exposed to different climatic conditions suggest that high soil temperatures are such a factor. The pattern of moth emergence from diapause pupae in the Gash Delta is compared with that found in Nigeria and Nyasaland.Natural mortality of D. watersi is discussed, and certain larval parasites, notably an un-named species of Apanteles of the ultor Reinh. group, and Bracon brevicornis Wesm., are considered to be of importance.The study of the biology of D. watersi has emphasised the difficulties in controlling this bollworm, and stressed the importance of attempting to destroy it in the diapause state, preferably during the “ dead ” season. It is considered that mechanical cultivation, of the soil may provide a means to that end.