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Page will reload when a filter is selected or excluded.- Clay Silo 2 results 2
- Grain Quality 2 results 2
- Level of Fill 2 results 2
- Maize 2 results 2
- Postharvest losses 2 results 2
- Silos have a fixed volume at the time of construction; harvests however vary from season to season. Complaints about severe postharvest losses in grains in the humid tropics of southern Nigeria necessitated a study into the effect of fill volume on quality of stored maize. Three clay silos labelled S1 to S3 of the same dimension and capacity (3.5 metric tonnes) were used. The silo walls were painted externally with gloss paint to reduce water absorption and filled with shelled maize. The first silo (S1) was filled with 3 tonnes, the second silo (S2) with 2 tonnes and the third (S3) filled with a tonne of maize for 6 months. Data was collected on microclimatic conditions within the silo and grain quality with increasing time of storage. Temperature, relative humidity (RH) and equilibrium moisture content (EMC) were recorded three times daily for each silo, focusing on the air between the grains and the headspace above the grains. Temperature fluctuations within S1 were smaller as indicated by the statistical range of 2 oC compared to S2 and S3 at 7 and 8 oC respectively. S3 showed high values of RH toward the end of storage, ranging between 65% to 80% at the top level and 76% at the bottom. EMC at the airspace above the grains in S1 increased from 12.0% at the beginning of storage in the dry season to 15.6% at the end of storage in the rainy season compared with S2 and S3 which increased from 12.0 to 17% and 12.0 to 17.2% respectively. Grains were found to be more prone to deterioration with decreasing level of fill because and increase in microbial activity was observed with a decreasing level of fill. Recommendations were made to farmers and grain aggregators on proper actions to take during grain storage given the peculiarities of the humid tropics. 2 results 2
- , yam tuber 1 results 1
- 2015, 2016 and 2017 have been confirmed the three warmest years on record and the degree of warming during these three years has been exceptional. Extremes of heat and cold environmental conditions have been known to be very detrimental to the health and comfort of humans. The severity of these adverse effects is often local and varies from one place to another though they are happening on a global scale therefore Temperature variation, Heat Index (HI) temperature and Dew Point Temperature (DPT) ( Meteorological comfort indices) were used to assess the effect of this condition in southwest, Nigeria. Air temperature and Humidity data were collected from meteorological stations situated in the southwestern states selected for study and was processed using the rule of Thumb for DPT calculations as expressed by Lawrence (2005) and Steadman (1979) formula simplified by Rothfusz’ model (1990) for HI temperature. The data analysis was done using Microsoft Excel Package and Statistical Package for the Social Sciences (SPSS), the following results were obtained: Elevation may affect temperature yet during extreme warmness other factors can have a greater influence on temperature and meteorological comfort indices used to assess extreme warmness in southwest Nigeria from this study showed greater impacts thus: Heat Index Temperature has highest values in Lagos State, while Dew Point Temperature have highest values in Ogun state. None of these extreme warmness measuring variables seem to be solely in favour of state Location in terms of coordinates and elevation; this suggests more anthropogenic influence forming the characteristics of the states to geographic locations of the states however, between the start year of extreme warmness (2015) and 2017, HI temperature showed a significant increase while average DPT did not really change during the period of extreme warmness. 1 results 1
- An experimental study was undertaken to evaluate and compare the performances of a local barn and a platform, as storage structures for yam tubers (Dioscorea rotundata poir.) The criteria used for evaluation and comparison were the degree of weight loss during storage, tuber sprouting and rotting of yam tubers during a 17 week storage duration between March and June 2008. Measurements of temperatures and relative humidity in the storage environment were taken thrice daily during the period. Weight loss in each tuber was measured weekly while sprouts were removed from tubers fortnightly. Results show that the average temperature and relative humidity on the platform were 30.4°C and 57.3% respectively while for the barn, they were 26.5°C and 55.5% respectively. The average weight loss in tubers in the barn during the duration was 32.8% while for tubers on the platform, it was 30.3%. Yam tubers on the platform recorded 5.4% sprouting while those in the barn had 4.9% sprouting. Palm leaves cover for yam tubers on the platform protected the tubers from excessive heat and moisture loss. Rotting was observed in 10% of the tubers stored in the barn but was completely absent from those stored on the platform. 1 results 1
- Barn 1 results 1
- Dew point temperature 1 results 1
- Extreme warmness 1 results 1
- Heat Index 1 results 1
- The need to improve the animal protein diet of the Nigerian population has underlined the importation of temperate-evolved cattle into Nigeria. How these animals adapt to the new environment should be of economic and scientific interest. Under the natural hot/humid subequatorial climate of Ibadan, some physiologic, adrenocortical and reproductive functions were investigated in 6 German Brown, 5 Holstein and 6 White Fulani heifers. The Brown/ Holstein and Fulani heifers attained puberty at the average eyes, with the standard deviation, of 17.8 + 1.6, 16.7 + 1.8 and 23.7 + 1.9 months respectively. Observations on estrous cycles showed that estrous period ranged between 7 and 31 hours in the three breeds, the mean values, with the standard errors, being 16.2+0.7, 15.8 ± 0.7 and 14.6 +_0.8 hours in the Brown, Holstein and Fulani heifers respectively. The difference between the Bos taurus and Bos indices cattle was slight but significant. Most estrus commenced during the day with a greater concentration in the morning time. The intensity of estrus was high in both species though, occasionally, a few Fulani heifers showed weaker estrual signs. Average estrous cycle length was slightly longer in the Brown and Fulani than in the Holstein heifers, the values, with the standard errors, being 21.0 + 0.3, 21.4 ± 0.2 and 20.1 + 0.2 days respectively. Ovulations occurred mostly within a day after estrus, and this as well as the duration of estrus and estrous cycle length showed no seasonal variations. There was no indication that Bos taurus and Bos indicus cattle under the semi-intensive management preferred any particular season for increased sexual activity or breeding in the sub-equatorial climate. Marked shifts occurred in the respiratory rates during four selected quarters of the year. Increases occurring in the dry hot season from the values in the relatively cooler season were highly significant. Both mean morning and mean afternoon values (l4 - 44 and 17 – 75 breaths per minute respectively) were highest in the Holstein and lowest in the Fulani heifers. Rectal temperatures showed slight but significant seasonal changes. Mean values were 101.3°F (38.5°C) and 102.2°F (39.0°C) in the morning and afternoon respectively for all the heifers together through the year. The lowest afternoon values occurred in the wettest and coolest months. The Fulani and Holstein heifers showed the lowest and highest mean values respectively. Diurnal and circadian shifts in the respiratory rates and rectal temperatures in the heifers were most exaggerated in the sun and in the Holsteins, the latter particularly exhibited polypnea and hyperthermia. Unlike the zebu, the Bos taurus cattle sought shade in the sun. The Holstein heifers sought shade more frequently and stayed there longer than the Brown heifers. Basal plasma cortisol concentrations at 07 - 08.00 hours, determined by radioimmunoassay during four quarters of the year was low, ranging between 1 - 10 ng/ml with occasional mid-cycle and more frequent- . proestrual and/or estrual elevations. Mean values showed slight but significant seasonal changes. The levels in the dry season were slightly lower than in the wet season. Breed differences were not significant. Diurnal and circadian plasma cortisol concentrations in heifers in the shade and in the sun showed no rhythmical pattern. Exogenous corticotrophin at and after mid-cycle stage elicited marked and prolonged adrenocortical response which varied between heifers, and did not alter estrous. cycle rhythmicity. A high adrenal reserve in the heifers was indicated. Bos taurus cattle have been found to be adaptable to the southern Nigerian climate represented by the Ibadan condition. Management practice should, however, ensure all-year-round provision of shade and adequate nutrition including the adoption of night grazing. The Brown cattle are recommended over the Holsteins because the former are more comfortable, A mixed herd of the two breeds should be discouraged because socially the Browns dominate over the Holsteins. The Fulani cattle are more adaptable to the subequatorial climate than the temperate-evolved cattle as evidenced by the physiological responses, artificial breeding should be suitable for the Fulani cattle as it is for the Bos taurus cattle. The need to adopt better management practices than hitherto existing, range system for the Fulani cattle so that their reproductive and productive attributes may be well manifested, is indicated. 1 results 1
- This study analyses the spatial, diurnal and seasonal characteristics of some climatic parameters within the urban canopy of Ibadan. These climatic parameters are global radiation, surface albedo, net long wave radiation and latent and sensible fluxes of energy. The analysis is based on data collected on a daily basis (0600 - 1800 hrs. GMT) for one year at twenty stations located all ever the city. Furthermore, twenty-year data (1961-80) on the characteristics of maximum and minimum temperatures, relative humidity and rainfall are analysed with the aim of analysing the effect of urbanization on climate over that period. This study makes a departure from earlier studies which were concerned mainly with the rural/urban dichotomy ir climatic parameters by actually looking into the intra-urban pattern of the climatic parameters. In this regard the city surface was classified into six land use categories on the basis of their components of buildings, water, tarred roads, untarred roads, paved surfaces, bare ground, lawns and trees. The laud-uses identified are 'high density’ built-up areas, 'medium density' built-up areas, 'low density 'built-up areas, 'commercial' areas, 'open spaces’ and ’rural’ areas. These land-uses were used as the basis for setting up the climatic stations and explaining results of the variation in climatic parameters. Results of the investigation show that components of radiation and energy budgets vary considerably from the rural areas to the urban centre. Global radiation values for the different land-uses range between 0,62 and 0.64 ly min-1 in the rural surroundings to between 0,56 and 0.58 ly min-1 in the urban centre. This shows a decrease of about Albedo mean values range between 15% and 18% in the rural area to between 8% and 10% in the city centre. The net radiation at the urban centre is about 15% higher than that at the rural area; the mean values for the different land-use surfaces being between 0.200 and 0.215 ly. Min-1 in the rural area and between 0.225 and 0.245 ly. Min-1 in the urban centre. Net long wave radiation increases from between -0.21 and -0.22 ly. Min-1 in the rural area to between —0.18 and -0.19 ly min-1 in the urban centre, The Increase in the city centre over the rural area is by about Mean values of temperature urban 'heat island' vary between 1.0°C and 1.5°C, and 2.5°C and 3.0°C during the vet and harmattan periods respectively, The extreme value of temperature 'heat island' is as high as 11.7°C. The relative humidity in the urban centre is 6,3% lower than in the rural surroundings during the wet season and 24.3% lower than the harmattan season. From the temporal analysis of climatic data over a 20-year period, it is found that temperature has increased significantly over time. Maximum temperature increased by as much as 0o7°Co Rainfall increase over time has also been related to urban effects. All these confirm that urbanization is changing the climate of Ibadan, Finally, land-use components and climatic parameters are correlated and the relationships between them are found to be statistically significant at 5% level of significance. 1 results 1
- Warmest years 1 results 1
- platform, 1 results 1
- sprouting, 1 results 1
- weight loss, 1 results 1
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