Direct and indirect methods of estimating lucerne (Medicago sativa) yield

Thesis (MScAgric)--Stellenbosch University, 2019.ENGLISH ABSTRACT: Lucerne (Medicago sativa) is an important drought tolerant fodder crop which plays an important role in providing feed for livestock in South Africa. Currently, the standard method for determining fodder on offer is the cut-and-dry method, which is time consuming, costly and labour intensive. There is therefore a need to find alternative non-destructive methods that can be used to accurately estimate lucerne yield in a time-efficient manner. The aim of this study was to calibrate a rising plate meter (RPM), ceptometer, meter ruler and canopy cover using an unmanned aerial vehicle (UAV) to estimate lucerne herbage yield. Data was collected from January 2015 till February 2018 with a break from June 2016 to June 2017. The study trial was conducted from July 2017 to February 2018 on existing lucerne trial plots under full irrigation at the Elsenburg Research Farm outside Stellenbosch. The first objective was to determine yield potential of lucerne cultivars available commercially in South Africa. Herbage yield data for 2015 was used to determine yield potential of different cultivars. Dormancy class did not affect herbage production in this study. The second objective was to calibrate indirect methods namely RPM, ceptometer and meter ruler, for estimating lucerne yield. Linear and quadratic regressions were calculated to estimate the accuracy of the RPM, ceptometer and meter ruler. Coefficients of determination derived from three yield estimations were significant (p<0.05). The RPM had the best coefficient of determination of r2 = 0.69 (p<0.05) compared to the other instruments. Operation was fairly easy and it achieved its objective of cutting down on time. It worked best on the months where lucerne production was low. The ceptometer (r2 = 0.55) was highly weather dependent as it worked best on clear sunny days and was affected on days with clouds and morning dew. The meter ruler was quick and easy to use to collect data. However, it could not produce a high coefficient of determination (r2 = 0.50). The third objective was to develop ways to use digital data collected with a UAV for estimating lucerne yield. Linear and quadratic regressions were also calculated to estimate accuracy of the UAV canopy cover. The UAV canopy cover estimations produced the lowest coefficient of determination of r2 = 0.45 compared to the other instruments. The drought experienced in the Western Cape Province during 2017 and part of 2018 cut the data collection period down to seven months from the expected twelve months. For the current study, it was concluded the RPM could be the best yield estimation instrument for estimating yield albeit there is room for it to be calibrated to get higher yield estimation accuracy. It is recommended the study is repeated over a longer period to properly calibrate all yield estimation instruments over all seasons of the year.AFRIKAANS OPSOMMING: Lusern (Medicago sativa) is ’n belangrike droogte-tolerante voergewas wat ’n belangrike rol in veeproduksiestelsels in Suid-Afrika speel. Huidiglik is die standaardmetode om ruvoerbeskikbaarheid te bepaal, die sny-en-droog-metode, wat tydrowend, duur en arbeidsintensief is. Daar is ‘n behoefte om alternatiewe, nie-destruktiewe metodes te vind wat akkurraat en op ‘n tyd-effektiewe manier, lusernopbrengs kan skat. Die doel van die studie was om die skyfmeter (RPM), septometer, meterstok en blaredakbedekking gemeet met ‘n onbemande lugvoertuig (UAV) te kalibreer om lusernopbrengs te bepaal. Data was van Januarie 2015 tot Februarie 2018 versamel, met ‘n breek van Junie 2016 tot Junie 2017. Die studie was uitgevoer op bestaande lusernpersele onder besproeiing by die Elsenburg Navorsingsplaas buite Stellenbosch. Die eerste doelwit was om die opbrengs van lusernkultivars wat kommersiëel beskikbaar in Suid-Afrika is, te bepaal. Opbrengsdata van 2015 was gebruik om opbrengspotenisaal van verskillende kultivars te bepaal. Dormansieklasse het nie ’n invloed op produksie in hierdie studie gehad nie. Die tweede doelwit was om die indirekte metodes, naamlik die RPM, septometer en meterstok te gebruik om opbrengs te bepaal. Liniêre en kwadratiese regressies was bereken om die akkuraatheid van die drie metodes te bepaal. Koëffisiente van bepalings was afgelei van drie opbrengsskattings, was betekensivol (p<0.05). Die RPM het die hoogste koëffisient gehad van r2 = 0.69 (p<0.05), vergeleke met die ander instrumente. Hantering van die RPM was redelik eenvoudig en tyd-effektief. Die effektiwiteit was egter die beste in maande wanneer lusernproduksie laag was. Die septometer (r2 = 0.55) het afgehang van die weersomstandighede en het die beste op sonnige dae gewerk, en was die meeste beinvloed op oortrokke dae en deur oggenddou. Die meterstok was maklik en eenvoudig om te gebruik, maar kon nie ‘n hoë koëffisient (r2 = 0.50) produseer nie. Die derde doelwit was om maniere om digitale data wat deur ’n UAV versamel was, te ontwikkel om lusernopbrengs te bepaal. Liniêre en kwadratiese regressies was ook gebruik om lusernopbrengs en die blaredak te korrelaar. Die UAV-skattings het die laagste koëffisient van r2 = 0.45 tot gevolg gehad. Die droogte wat in die Wes-Kaap gedurende 2017 en 2018 ondervind was, het veroorsaak dat die dataversamelingstyd van 12 na sewe maande verkort was. Die gevolgtrekking was dat die RPM die beste opbrengskattingsinstrument was, alhoewel daar nog plek vir verbetering is om nog beter akkuraatheid te verseker. Dit word aanbeveel dat die studie herhaal word oor ‘n langer tyd om die inligting verder te verfyn.Master

A History of the Last Church of God and His Christ

Some scholars classify the Last Church of God and His Christ under the ecclesiastical-cultural bloc known as African Indigenous Churches (AICs). David Barret has divided the world's Christians into seven major ecclesiastical blocs. However, there are many large churches and denominations which do not define themselves under any of these three terms, and often reject all three. As far back as 1549 (Japan) and 1741 (USA), new types of Christianity have emerged that do not fit readily into any of these preceding six major blocs. These consist of denominations, churches and movements that have been initiated, founded and spread by black, Non-White or non-European peoples without European assistance, mainly in the Global South, but also among Black and Non-White minorities in the Western World. The African Indigenous Churches fall under this category. The aim of the book, is to examine the history of the Last Church of God and His Christ International in Malawi from its beginning (1916) through the years and to portray a picture of its current existence in its various branches: What developments and changes have taken place over the years? What has been the relationship of the church to African culture? How has the church grown or expanded? Has the church been able to maintain its unity? And what has been the relationship of the church with other churches

ZETDC inspect to connect mobile application

The need to develop an Inspect to Connect Mobile Application (ZETDC ITC) was necessitated by the lack of a facility that was convenient in the operations of electrical inspection to the connection procedures. Clients had to incur expenses of travelling from one point to another for them to get inspection and connection services, despite having to travel long distances to ZETDC offices they also had to wait for hours in queues waiting to be attended to. Employees also ended up having burnout syndrome and fatigue due to working extra hours as well as writing some monotonous weekly and monthly reports. The development of the new system using android and PHP (for back end application) helped to curb the challenges faced by customers as well as the employees since most of the client electrical inspection and connection procedures are now done at the comfort of their homes and employees reports are now auto generated by the system. Data was gathered using interviews, observations and questionnaire as the data gathering methodologies with the intention of understanding the operations of the old system and identify problems that were being faced as well as determining the requirements and functionality that was being expected in the new system. Feasibility study was undertaken and the results permitted the project team to go to the next development procedure. Alternatives were evaluated on which way to develop the new system and in-house development was recommended since it was the best alternative among others. The system was installed using parallel changeover as the changeover strategy since this was considered safe enough to countermeasure the risks of data loss in case of a system failure. The project team decided to implement all the maintenance strategies since they considered them to serve different purposes. The new system should accommodate the use of USSD code for nonandroid users, as well as for the clients with internet access problems, for client fault reporting and purchase of ZETDC electricity token

The legality of internet shutdowns in Zimbabwe

In an ever-increasingly global age, the world has become dependent on the internet for communication purposes and transacting, the internet has become a conduit through which people exercise realise their rights. The internet provides enhanced connectivity of persons and offers a platform for free expression. The internet has further become a conduit through which individuals can realise the right to freedom of expression. Autocratic governments that feel threatened by the difficulty of regulating the internet have resorted to shutting down entire communication systems leaving their citizens stranded and frustrated. Governments have been overtaken by technological developments which have been particularly rapid in the 21st Century. As such in situations where legislation fails to regulate modern communication structures, this leads to undesirable situations where governments use outdated legislation which does not grant authority to act in such a manner. The study answers the question of whether internet shutdowns are legal in Zimbabwe and in so doing examines the impact of internet shutdowns on the right to the freedom of expression. The study explores the relationship between the internet and the right to freedom of expression examining the boundaries of free expression and the circumstances under which as a right it can be limited. The study identifies how in order for rights to be limited such limit should be proportional, provided for in the law and should seek to serve a legitimate aim. An analysis of Zimbabwe’s constitutional provisions on the right to freedom of expression and how they reverberate with international principles on the right to freedom of expression. An examination of the scope of government’s powers in respect of the Interception of Communications Act in order to determine if there is in place a legal framework that authorises the shutting down of the Internet is conducted. In line with this is a consideration of the possible justifications for shutting down communications which include the need for the preservation of the national security. The study encompasses perspectives from the jurisdiction of Pakistan in order to obtain insight into the justifiability of internet shutdowns in a modern democratic society. It is arrived at a conclusion that internet shutdowns have no place in Zimbabwean law as there is no legislation that so provides for such a phenomenon. Furthermore, the justifiability of shutting down communications for whole communities is a drastic and draconian move. Recommendations are thereby proffered to the government on how best it can maintain national security without depriving entire populations of their ability to communicate freely

Experimental investigations of shock-wave/boundary-layer interactions in transonic aircraft engine intakes at high incidence

This paper presents results from a simplified experimental rig that aims to replicate the key physics of a transonic aircraft intake at high incidence for realistic altitudes. The equivalent flight conditions replicated are for free stream Mach numbers M∞ = 0: 25 - 0: 45 and incidence angles in the range α = 30 ± 5°. Measurement techniques from the simplified two-dimensional geometric setup include; schlieren imaging, surface oilflows, pressure sensitive paint, pressure and temperature measurements. CFD models that look to predict this behaviour have a limited accuracy largely due to a lack of experimental validation data - this lends itself as one of the key motivations for the work presented in this paper. Currently there is good qualitative agreement between the experimental results and the initial computation(s)

Transitional shock-wave/boundary-layer interactions in intakes at incidence

© Springer International Publishing Switzerland 2016. The work here presents an experimental and computational study of a simplified intake bottom lip at incidence. The experiments are carried out in a small-scale blow-downwind tunnel.Computations are carried out in parallel to experiments using an in-house unstructured compressible flow solver. Evaluation of current Reynolds Averaged Navier-Stokes (RANS) methods are conducted and compared to experimental measurements. Qualitative results showgood agreement of experiments to the computations, although further analysis is required. Current computational strategies followa steady, quasi-two-dimensional approach, with fully structuredwall-resolved grids

Prevalence of bacterial contamination in blood and blood products at the National Blood Service Zimbabwe

Introduction: Advances in screening for infections improve the safety of donated blood. Transfusion-related bacterial sepsis, although not established in Zimbabwe, stills makes bacterial contamination of blood clinically relevant. Methodology: This cross-sectional study was conducted in Harare. Bacteriological and antibiotic susceptibility testing were done using standard methods. Results: Of the 196 samples analyzed, 6 (3.1%) were contaminated with bacteria. Platelets had a significantly high contamination rate compared to other blood products. Bacteria showed varying patterns of susceptibility to the antibiotics tested. Conclusions: The prevalence of bacterial contamination in blood products suggests that patients who receive blood products are at risk of developing infection.</jats:p