66 research outputs found
Simulating planting date and cultivar effects on dryland maize production using CERESmaize model
Open Access JournalMaize farmers and extension agents in dry sudan savanna need information on how planting date and the choice of variety affect grain yield. This study was conducted to test the ability of model to predict maize yields under varying planting dates. Data on two open-pollinated maize cultivars (TSB-SR and TZE-COMP4) sown on different dates (June 29th, July 13th, July 21st and July 28th) in 2006 and 2007 at Azir (11Ā° 01.820Ā“ N, 12Ā°37.714Ā“ E; 441 m) and Damboa (11Ā° 10.379Ā“; 12Ā° 47.145Ā“E; 396 m) in the Sudan Savanna of Nigeria were used in running the model. Experimental data from Azir in 2006 was used to calibrate the model, while the data for 2007 at Azir 2006 and 2007 at Damboa were used for model validation. The model predicted days to anthesis at Damboa as reasonably well in both 2006 and 2007 (d-index >0.8), while at Azir, the prediction of days to anthesis was very poor in 2007. The match between predicted and observed grain yield were very good in 2007 at both locations. The root mean square error (RMSE) values for grain yield in 2007 were 431.5 and 226.5 kg ha-1 at Azir, and 799.5 and 611.5 kg ha-1 at Damboa for TZB SR and TZE COMP4, respectively, while the d-index values were all greater than 0.94. Generally, the model predicted decrease in grain yield with delay in planting date except for TZB-SR at Azir in 2006 where planting on July 13th gave higher yield than planting on June 29th. The grain yield values from the simulations suggested late June to early July as the optimum planting window for both varieties at both Azir and Damboa
Effect of Cover Crops, Lime and Rock Phosphate on Maize (Zea mays L.) in an Acidic Soil of Northern Guinea Savanna of Nigeria
Phosphorus deficiency is the major constraint to maize production in acidic soil of Heipang (9Ā°38ā, 8Ā°53ā) in Northern Guinea Savanna of Nigeria. The soil is high in sesquioxides and soluble aluminum and has high phosphate sorption capacity. To address this problem, a field trial was conducted between 1996-1997 to assess the responses of six tropical cover crops and maize to lime and applied rock phosphate and to evaluate the effect of these treatments on the performance and P nutrition of succeeding maize. Results of the trial showed that planting Chamaecrista rotundifolia, Lablab purpureus, Mucuna pruriens, and maize-Chamaecrista rotundifolia intercrop reduced the leaf Al concentration of succeeding maize by more than 38%. Although none of the six cover crops significantly increased grain yields of succeeding maize, C. rotundifolia was the most consistent in improving maize performance while Glycine max produced the least performance. Concentration of Mn in the index leaves of maize was significantly higher on plots where G. max preceded maize, thus accounting for the poor performance of maize on these plots. Application of Sokoto Phosphate Rock at 30 kg ha^(-1) to cover crops produced very significant improvement in the yields of succeeding maize. While liming with 1.35 t CaO ha^(-1) in 1997 raised the soil pH value by 0.2 and significantly improved total P uptake by maize
CERES-maize model for determining the optimum planting dates of early maturing maize varieties in northern Nigeria
Open Access JournalField trials were carried out in the Sudan Savannah of Nigeria to assess the usefulness of CERESāmaize crop model as a decision support tool for optimizing maize production through manipulation of plant dates. The calibration experiments comprised of 20 maize varieties planted during the dry and rainy seasons of 2014 and 2015 at Bayero University Kano and Audu Bako College of Agriculture Dambatta. The trials for model evaluation were conducted in 16 different farmer fields across the Sudan (Bunkure and GarunāMallam) and Northern Guinea (Tudun-Wada and Lere) Savannas using two of the calibrated varieties under four different sowing dates. The model accurately predicted grain yield, harvest index, and biomass of both varieties with low RMSE-values (below 5% of mean), high d-index (above 0.8), and high r-square (above 0.9) for the calibration trials. The time series data (tops weight, stem and leaf dry weights) were also predicted with high accuracy (% RMSEn above 70%, d-index above 0.88). Similar results were also observed for the evaluation trials, where all variables were simulated with high accuracies. Estimation efficiencies (EF)-values above 0.8 were observed for all the evaluation parameters. Seasonal and sensitivity analyses on Typic Plinthiustalfs and Plinthic Kanhaplustults in the Sudan and Northern Guinea Savannas were conducted. Results showed that planting extra early maize varieties in late July and early maize in mid-June leads to production of highest grain yields in the Sudan Savanna. In the Northern Guinea Savanna planting extra-early maize in mid-July and early maize in late July produced the highest grain yields. Delaying planting in both Agro-ecologies until mid-August leads to lower yields. Delaying planting to mid-August led to grain yield reduction of 39.2% for extra early maize and 74.4% for early maize in the Sudan Savanna. In the Northern Guinea Savanna however, delaying planting to mid-August resulted in yield reduction of 66.9 and 94.3% for extra-early and early maize, respectively
Efficiency Analysis on Small Sized Generators in Nigeria
In this paper, efficiency analysis of small sized generators in Nigeria was considered. Experimental analyses were carried out on two (2) different samples of generators tagged āSā and āTā at different loading conditions (20%, 40%, 60% etc. of ratings) to ascertain the generatorsā efficiencies as well as the maximum true power that could be drawn out from the generators. The experimental results are compared with the manufacturers ratings specified on the name plate of the generators. The results indicated an average efficiency of 44.9% and 55.7% for āTā and āSā respectively an indication that generator āSā is more efficient that āTā. The results also showed that the values of the power factor indicated on the generators are inaccurate as none of the generators could give the maximum power as indicated on their name plates based on the experimental analysis carried out. The generators selected were able to provide adequate power to the selected loads with efficiencies not up to 100% of the expected rated value of the generators. For generator āSā it was observed that the efficiency decreases from the highest rating to the lowest rating. Conclusively, this result suggests that portable generators dealers are taking advantage of the energy crises to importing generators not up to specifications to the Nigerian market at the expense of naĆÆve customers. This paper recommends that proper standards and measures be put in place and enforced by the relevant authority for conformity of standards to all imported generators to save guard and protect the interest of potential customers and Nigerians
Gender Analysis on Food Consumption Patterns for Enhancing Food Security in Nigeria
Traditionally, there has been a strict division of labor by gender in agriculture in Africa. Men and women participate in agriculture, the task may be gender specific but they are complementary and reciprocal. This article analyses different roles performed by men and women in food conservation strategies for enhancing food security in Nigeria. The study was conducted in two villages each in Kano and Katsina States of Nigeria. A total number of households interviewed in this survey was 282. Food Security Index (Zi) was used to measure the food security status of farming households. Harvard Analysis Framework was used to assess the distinctive gender roles in these communities. The result shows that male farmers were responsible for conducting most of the farming related activities in the study areas, women farmers were responsible for harvesting, pounding and threshing in addition to selecting the varieties. An interesting aspect of the study was the ability of the households to conserve the staple foods throughout the year, which was useful towards enhancing food security and periods of food availability and shortage were also assessed to find out the extent of food security among the household members. Staple foods that are the main sources of carbohydrates were readily available and consumed every day. Protein sources among the foods vary between plant and animal sources. Plant source was consumed every day, while the animal source was consumed occasionally, mostly once or twice a week. Any interventions that focus on promoting access and control of resources in these communities would be instrumental in increasing level of womenās productivity in agricultural and related activities
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Implementation of and Early Outcomes From Anal Cancer Screening at a Community-Engaged Health Care Facility Providing Care to Nigerian Men Who Have Sex With Men.
PurposeAnal cancer risk is substantially higher among HIV-infected men who have sex with men (MSM) as compared with other reproductive-age adults, but screening is rare across sub-Saharan Africa. We report the use of high-resolution anoscopy (HRA) as a first-line screening tool and the resulting early outcomes among MSM in Abuja, Nigeria.MethodsFrom August 2016 to August 2017, 424 MSM enrolled in an anal cancer screening substudy of TRUST/RV368, a combined HIV prevention and treatment cohort. HRA-directed biopsies were diagnosed by histology, and ablative treatment was offered for high-grade squamous intraepithelial lesions (HSIL). HRA proficiency was assessed by evaluating the detection of squamous intraepithelial lesions (SIL) over time and the proportion biopsied. Prevalence estimates of low-grade squamous intraepithelial lesions and HSIL with 95% CIs were calculated. Multinomial logistic regression was used to identify those at the highest risk of SIL.ResultsMedian age was 25 years (interquartile range [IQR], 22-29), median time since sexual debut was 8 years (IQR, 4-12), and 59% (95% CI, 54.2% to 63.6%) were HIV infected. Rate of detection of any SIL stabilized after 200 screenings, and less than 20% had two or more biopsies. Preliminary prevalence estimates of low-grade squamous intraepithelial lesions and HSIL were 50.0% (95% CI, 44.7% to 55.3%) and 6.3% (95% CI, 4.0% to 9.3%). HIV infection, at least 8 years since anal coital debut, concurrency, and external warts were independently statistically associated with SIL.ConclusionProficiency with HRA increased with experience over time. However, HSIL detection rates were low, potentially affected by obstructed views from internal warts and low biopsy rates, highlighting the need for ongoing evaluation and mentoring to validate this finding. HRA is a feasible first-line screening tool at an MSM-friendly health care facility. Years since anal coital debut and external warts could prioritize screening
Economics of On-Farm Sorghum "ā Legume Strip Cropping System in Kano State, Nigeria
The study was conducted to carry out Economics of Alliance for Green Revolution in Africa (AGRA) on-farm Sorghum-legume strip cropping system in Kano State. Structured questionnaire was used and data were collected from 229 farmers randomly selected from three purposively selected Local Government Areas (LGAs). The Data were analyzed using descriptive statistics, gross margin analysis, profitability ratios and Paired T-test. The results revealed that 75.6% of the farmers were in active age of within 25-54 years with a mean age of 45 years. Majority of the farmers were male (93.4%); 58.5% had acquired qua'ranic education and 97.4% were married with many household size of between 7-11 household (46.3%).Ā The results of gross margin showed that the improved practice made a profit of N65, 931.64k/ha and a return on every naira invested of N2.08, compared with N56, 008.62k/ha and a return on every naira invested of N1.94in the traditional systems.Ā Result on T-test showed that there is significant difference between profits of some improved practices against farmers practice (p< 0.05). The constraints to production experienced by the farmers were high cost of inputs, insufficient fund, inadequate and untimely delivery of farm input, inadequate collaterals/security, inadequate loan/credit facilities, inadequate storage processing and marketing facilities, pest, and diseases. Other less severe problems identified were Striga infestation, unstable produce price and drought spells.Ā It was concluded that the technology package is more profitable.Ā It is recommended that farmers should increase land devoted to Sorghum- legume strip cropping system and government and other agencies like ADPs should address the challenges of shortage of extension services, credit supply to farmers, improve marketing system, input supply and affordable price of input
Optimizing sowing density-based management decisions with different nitrogen rates on smallholder maize farms in northern Nigeria
Open Access Article; Published online: 18 Jan 2021In this study, the CERES-Maize model was calibrated and evaluated using data from 60 farmersā fields across Sudan (SS) and Northern Guinea (NGS) Savannas of Nigeria in 2016 and 2017 rainy seasons. The trials consisted of 10 maize varieties sown at three different sowing densities (2.6, 5.3, and 6.6 plants mā2) across farmersā field with contrasting agronomic and nutrient management histories. Model predictions in both years and locations were close to observed data for both calibration and evaluation exercises as evidenced by low normalized root mean square error (RMSE) (ā¤15%), high modified d-index (> 0.6), and high model efficiency (>0.45) values for the phenology, growth, and yield data across all varieties and agro-ecologies. In both years and locations and for both calibration and evaluation exercises, very good agreements were found between observed and model-simulated grain yields, number of days to physiological maturity, above-ground biomass, and harvest index. Two separate scenario analyses were conducted using the long-term (26 years) weather records for Bunkure (representing the SS) and Zaria (representing the NGS). The early and extra-early varieties were used in the SS while the intermediate and late varieties were used in the NGS. The result of the scenario analyses showed that early and extra-early varieties grown in the SS responds to increased sowing density up to 8.8 plants mā2 when the recommended rate of N fertilizers (90 kg N haā1) was applied. In the NGS, yield responses were observed up to a density of 6.6 plants mā2 with the application of 120 kg N haā1 for the intermediate and late varieties. The highest mean monetary returns to land (US957.7 haā1) was simulated for scenarios with 6.6 plants mā2 and 90 Kg N haā1 in the SS. In the NGS, monetary return per hectare was highest with a planting density of 6.6 plants mā2 with the application of 120 kg N, while the return to labor was highest for sowing density of 5.3 plants mā2 at the same N fertilizer application rates. The results of the long-term simulations predicted increases in yield and economic returns to land and labor by increasing sowing densities in the maize belts of Nigeria without applying N fertilizers above the recommended rates
Drought tolerance mechanisms for responses to pre and post flowering drought stress of groundnut in a dryland ecology
Understanding the mechanisms of groundnut tolerance to pre and post flowering drought stress is important for improving its yield and phenological development in the drylands. The mechanisms of drought tolerance are known to be under variable genetic control. The aim of this study was to investigate the mechanism of drought tolerance of various groundnut genotypes to pre and post flowering drought stress. Screen house trials were undertaken between March and June 2014. Three moisture management treatments were imposed on 10 groundnut cultivars. Three cultivars (Ex-Oakar, Samnut 23 and Samnut 24) are known to have some drought tolerance characteristics; two cultivars (Samnut 21 and Samnut 22) do not tolerate drought, while the drought response ofthe remaining five cultivars (Samnut 25, Samnut 26, Sabiya, Kwankwaso and Yar Oigir) is not known. The water managements were: Field Capacity throughout the period of experimentation (FCT), Imposition of PreFlowering Moisture Stress (PrFS) and Imposition of Post Flowering Stress (PoFS). Stomatal conductance and relative water content (RWC) were recorded at 10, 15, 20, 25, 30, 35,40 and 45 days after emergence. Total dry matter samples (shoots and pods) were collected at 15 and 25 days after emergence, R5 and R7. From these samples, shoot and pod growth rates were calculated. Two ofthe drought tolerant cultivars were found to tolerate only pre-flowering drought and only Ex-Oakar tolerate both pre and post flowering drought stress. Among the two susceptible cultivars, Samnut 22 was found to tolerate post-flowering stress, but was susceptible to pre flowering stress. Samnut 26 and Kwankwaso tolerated both pre and post flowering stress, while Sabiya and Yar Oigir were susceptible to both stresses. Most of the cultivars adopted the mechanism of conserving water by reducing transpiration to maintain high RWC. Only Samnut 24 showed the mechanism of improving assimilate partitioning to the pods at grain filling phase. The knowledge gathered could be used for breeding groundnut that will be suited to the drylands in order to escape periods of intermittent drought
Effect of high-pressure rolling followed by laser processing on mechanical properties, microstructure and residual stress distribution in multi-pass welds of 304L stainless steel
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