Determinants of cassava commercialization for export development among farmers in Abia state

This review presents an overview of how genomics have developed over the years and how genomic tools have helped to change our approach to crop improvement. In the years preceding now, Plant breeding has been very successful in developing improved varieties using conventional tools and methodologies. Nowadays, the availability of genomic tools and resources has led to a new revolution of plant breeding, as they facilitate the study of the genotype and its relationship with the phenotype, in particular for complex traits. Recent technological advancements like Next Generation Sequencing (NGS), Genome-wide expression studies, Resequencing of genomes for the genome-wide discovery of markers amenable for high-throughput genotyping platforms, like SSRs and SNPs, or the construction of high density genetic maps, have substantially expanded our ability to analyze and understand plant genomes and to reduce the gap existing between genotype and phenotype. The fast evolving field of genomics allows scientists to analyze thousands of genes in parallel, to understand the genetic architecture of plant genomes and also to isolate the genes responsible for mutations. Conclusively, advances in genomics are providing breeders with new tools and methodologies that allow a great leap forward in plant breeding, including the ‘superdomestication’ of crops and the genetic dissection and breeding for complex traits. Keywords: Genotyping, phenotyping, genomics, and sequencin

Food grain yield response to climate variability in Nigeria: an empirical analysis

The effect of variability of climate parameters on grain yield and the proportion of change in production that is due to impact of climate variability demands urgent attention. This study looks at the consequences of climate variability on grain yield in Nigeria within 1970-2012.The result revealed that the yield of rice was negatively affected by rainfall (p=0.1) and (p=0.05) for fertilizer quantity. Maize yield was observed to be influenced negatively by area harvested (p=0.1). Based on these findings, the use of improved high yielding varieties, availability of more input supplies, introduction of improved farming techniques and cultural practices are necessary to increase the yield of these grains.Keywords: climate variability, yield and grain, cultural practice

Effects of Climate Variability on Grain Yield in Nigeria: An FM-OLS Model Approach

The study empirically explored the effects of variability in climate parameters on yield of two grain crops grown in Nigeria (millet and sorghum). This study was based on time series data obtained from various sources spanning from 1970 to 2012. Data obtained were analyzed using fully Modified Ordinary Least Square (FM-OLS) approach. The results showed that land area expansion (lnarea) exerted a significant effect on yield of sorghum in the study at a 5% level of significance within the period of study. For millet, the results indicated that climate variable (mean annual temperature), CO2 emissions as well as land area expansion significantly impacted on the yield of the crop in the study. It is recommended that land expansion should be accompanied by intensive utilization of inputs which could help to boost the yield of sorghum and millet in the study area

Heat transfer correlations and pressure drop dynamics of palm fibre wetting media for evaporative cooling at different air flow rates

© 2023 Elsevier Ltd and IIR. All rights reserved. This is the accepted manuscript version of an article which has been published in final form at https://doi.org/10.1016/j.ijrefrig.2023.07.008The thermal and flow resistance properties of wetting pads play a key role in how effective direct evaporative cooling (DEC) systems Perform. To make an informed decision, it's crucial to study the heat transfer properties and airflow resistance manifested in pressure drop for various types of wetting media. An experimental study was conducted to determine pressure drop and heat transfer correlation constants at three airflow rates for palm fruit mesocarp fibres (PFMF) wetting media. Heat transfer and pressure drop equations were fitted with generated data to obtain correlation constants. The wetting media were effective to lower the ambient temperature at an average depression of 6.6 to 8.2 °C and increase the relative humidity of the inlet air at an average value of 25.54 to 39.32%. PFMF had a low-pressure drop per unit length, ranging from 5.29 to 7.62 Pa/m, which makes it an appealing alternative to other wetting media. New correlation constants generated for pressure drop and heat transfer data fit well with high coefficient of determination (R2) values. The average cooling efficiency ranged from 56.43 to 65.27%, while the average Merkel number was 0.16 to 0.19. The Nusselt number increased with the Reynolds number and showed a laminar flow. Amaranths stored in DEC produced respiratory heat ranging from 290.86 to 336.53 mg/kg/h for all air velocities. Considering the respiratory rate within the range of cooler temperatures, it is recommended to use the DEC only for short periods or for pre-cooling of vegetable storage.Peer reviewe

Analysis of the influence of outdoor surface heat flux on the inlet water and the exhaust air temperature of the wetting pad of a direct evaporative cooling system

© 2023 Elsevier Ltd. This is the accepted manuscript version of an article which has been published in final form at https://doi.org/10.1016/j.applthermaleng.2023.120292The study investigates the interconnectivity between the inlet water temperature, wind flow rate, and storage water heat flux with the performance of biomass wetting pads in direct evaporative cooling under the external ambient condition of Sub-Saharan Africa. Thus, a standalone direct, evaporative cooling system with an upper water storage tank exposed to wind flow was locally developed and evaluated with jute, palm fruit mesocarp and wood charcoal as biomass cooling pad at three air velocities and constant pad thickness and three different air flow rates. The results indicated that increasing the heat flux around the water tank and decreasing the relative humidity of the inlet air through the wetting pad will lower both the inlet water and pad exhaust temperatures. The water demand was higher in palm fruit mesocarp fibre at airflow rates of 3 m/s, while at 4 and 4.5 m/s, it was higher in wood charcoal, and the value ranged from 9.64 × 10 −4 to 1.46 × 10 −3 kg/s. Except for jute fibre at 4 m/s, higher humidity difference or low cold room temperature did not translate to higher evaporative cooling effectiveness or efficiency. However, the lower inlet water temperature significantly affected the evaporative effectiveness. This shows the possibility of free moisture transfer into the cold room from the pad materials at increased air flow rates that helped boost the exhaust air's humidity. The average evaporative efficiency for the three pads ranged from 56.4 % to 80.96 %. The values for the enlargement coefficient ranged from 5 to 6.82, while the temperature thermal stress ranged from 24.37 to 28.66 °C.Peer reviewe

Progressive review of solar drying studies of agricultural products with exergoeconomics and econo-market participation aspect

An analysis of review articles on solar drying of agricultural products is presented. The review also discusses detailed economic evaluation methods and market participation approaches for transitioning solar dryers from the workshop to the market. This study aims to serve as a model for future solar drying reviews. In addition to broad perspective reviews, most reviews focused on using thermal storage, hybrid technologies, solar greenhouses, 4E evaluations, software applications and crop quality. From most of the reviews, solar dryers with thermal storage are now a viable substitute for fossil energy source dryers and can provide the continuous temperature range of 40–60 °C required to dry food crops. When phase change material is deployed, the transition temperature should be at 5 °C above the desired drying temperature. However, all reviews included sections on types, classification, mode of airflow through the collector, and use of thermal storage in solar drying. Hence, the authors review nearly the same research material, but review gaps remain. Thus that aspect was covered by examining the economic and exergoeconomic analysis methods used in solar dryer evaluations. Again agribusiness inter-phasing between researchers and users, which will spore market participation of solar dryer fabricators lacking in the literature were presented. Therefore, for a more market-oriented development of solar thermal technologies, solar dryer producers must engage in market-oriented production. The nature of markets located at different places calls for better strategies to improve market orientation and access to solar dryers and fabricators