To date, research on organic farming and certification has focused on the production and trade possibilities of the industry. Farmers‟ opinions are underrepresented and this study endeavours to capture their opinions. In this study, the economic problem is to investigate the low participation of farmers in certified organic farming, highlight the economic benefits which are normally not clearly defined, as well as study the often complicated and frustrating certification process. The main objective is to investigate the determinants, which affect the smallholder farmer‟s participation, and to analyse farmers‟ perceptions of certified organic farming in the Limpopo Province of South Africa. The specific focus was on the participation of smallholder farmers in certified organic farming. The dependent variable was participation as measured by a farmer‟s decision to either certify their farm or not. The independent variables included factors that make up farmer and farm characteristics, certification and market related characteristics. The study used a standard questionnaire to obtain information from farmers. The research methodology, analysis and the presentation of the study was quantitative. The study used descriptive statistics (percentages, means, standard deviations, Chi-squares and significance intervals) to evaluate the significance of the variables. These were analysed and described quantitatively by making use of EVIEWS and IBM AMOS software. In estimating the influential factors, a probit model was adopted, and in analysing farmer perception, structural equation modelling was used. v Descriptive statistics indicated that among farmers interviewed, the majority (61%) were female farmers and 39 per cent were male farmers. Among the female respondents, 46% participated in certified organic farming and 15 per cent of female farmers were not certified organic farmers. From the male group, 29 per cent were certified organic farmers and 7% were not. In determining factors influencing farmer participation, three of the variables were positively associated with the probability of participating in certified organic farming, these being: the age of the farmer, membership to a farmer organisation and market premium prices for certified commodities. The other five significant factors were negatively associated with the probability of participating in certified organic production. These factors were: the gender of the farmer, the farmers‟ income, farming experience, information access and certification costs. All these factors tended to decrease the likelihood of participating. With the exception of the farmers‟ income and farming experience, all the significant variables had the expected signs. Farmers‟ perceptions of certified organic farming were analysed and the results showed that a high percentage of farmers had a positive view of certified organic farming. In other words, the perceived benefits of certified organic farming meet farmers‟ expectations. The perceived premium price of certified organic products is the most important factor affecting farmer perception. This is not unusual because South Africa‟s organic production is mainly focused on exportation and targets high value markets. As hypothesized, the costs associated with the certification process, that is: inspection costs (-0.578) and annual certification costs (-0.719), negatively affect farmer perception. In conclusion, a combination of factors influence a farmer‟s decision as to whether or not to participate in certified organic farming. One cannot rely only on specific factors to determine farmers‟ participation in certified organic farming. Farmer perception of certified organic farming is also an important aspect. The more farmers positively perceive the farming enterprise, the higher the rate of participation will be. The same applies to the perceived costs, which have a negative impact on participation. The study finally recommends that government complete and put into practice the South African organic regulations, which may motivate farmers to get involved in certified organic farming and encourage local capacity building in certified organic farming. However, in the meantime, government should place an vi emphasis on self-regulation within farmer groups and cooperatives for organic production, and set up a regulator to monitor the current activities. This would enhance interest from potential farmers, and strengthen consumer confidence. The study further recommends that information on organic farming should be improved by encouraging more research in this area, which will enable farmers, consumers and regulators to access data on socio-economic, production and trade in the industry. Government should support or create a partnership between farmers and processors to establish cost effective processing of organic products and to increase the availability of processed products for market. Government should assist non-certified smallholder organic farmers to become certified, potentially resulting in a price premium for their products and enhancing export capabilities. / Dissertation (MSc Agric)--University of Pretoria, 2013. / gm2014 / Agricultural Economics, Extension and Rural Development / unrestricted

The aetiological diagnosis of recessive non-syndromic hearing loss poses a challenge owing to marked heterogeneity and the lack of identifying clinical features. The finding that up to 50% of recessive non-syndromal genetic hearing loss among Caucasians was due to mutations in GJB2, the gene encoding Connexin 26 (Cx26) was a breakthrough, whose value as a diagnostic tool has been limited by the significant variation in the prevalence of deafness genes and loci among population groups. The significant association of the GJB6-D13S1830 deletion among individuals with one mutant GJB2 allele highlighted the need to explore population specific genetic mutations for NSHL. Although data from Sub-Saharan Africa is limited, reported studies found a high prevalence of R143W GJB2 mutation among Ghanaian, the 35delG mutation in 5 out of 139 Sudanese and a low prevalence of GJB2 variations among 385 Kenyan deaf children. The mutation spectrum of Waardenburg Syndrome (WS) in Africans has not been documented. During a visit to a School for the Deaf in the Limpopo Province of South Africa in 1997, it was noted that a high number of students came from Nzhelele sub-district. All had childhood onset hearing loss with no associated anomalies or disorders. The question arose as to whether there was a high-risk area for deafness in the Limpopo Province and what the aetiology of this hearing loss was.The main aim of this study was to investigate the role of GJB2, the GJB6-D13S1830 deletion, and the four common mitochondrial mutations, A1555G, A3243G, A7511C and A7445G, in the African hearing-impaired population of Limpopo province in South Africa, and to identify the mutation spectrum of the deafness genes found. The type and degree of hearing loss in this hearing impaired population would also be assessed. Secondly, this study sought to identify the mutations in a sibling pair with 2 clinical WS and to use the findings in a future study to establish the mutation spectrum of WS in the African population of the Limpopo province and of South Africa in general. The study was designed as a two phase study, in which phase 1 was used for hypothesis formulation and phase 2 was for hypothesis testing. While phase 1 was a descriptive retrospective case study, phase 2 was a combination of sample survey and prospective descriptive case study. In phase 1, demographic data of 361 students in two schools of the deaf in the Limpopo province was analyzed for evidence of areas of high risk populations for deafness in the province. In phase 2, a group of 182 individuals with genetic non-syndromic hearing loss (NSHL) and two siblings with clinical WS from two schools for the Deaf in the Limpopo Province of South Africa were investigated. A thorough clinical examination, audiological evaluation and urinalysis were done. Mutational screening was carried out in all 184 subjects using genomic DNA using single-strand conformation polymorphism (SSCP), multiplex polymerase chain reaction (PCR), and direct sequencing for GJB2, and Restriction Fragment-Length Polymorphism (PCR–RFLP) analysis for GJB6, and SSCP, hetero-duplex analysis, and direct sequencing of the first 8 exons of PAX3 and all of MITF for Waarenburg syndrome. Data analysis was by geographical mapping, frequency tables, tests of association with calculation of odds ratios, and binary logistic regression analysis using STATA and GIS mapping systems. The results indicate that there seem to be areas of genuine populations at risk for hearing loss in the Limpopo province of South Africa, namely Mutale and parts of Makhado and Thulamela municipalities. In Thulamela (NP343) wards 11-15, 26-30 and 31-35, and in Mutale (NP 344) wards 6-10, together accounted for 67 (18%) of participants in phase 1, and 33 (18%) of the participants in phase 2 of the study. Mutale municipality in the Vhembe 3 district gave with a projected prevalence of at least 13.14 deaf children per 100,000 African population attending the local school for the deaf. The observed hearing loss is a genetic, non-syndromic form, which is mainly severe and severe to profound, although without any clear defining configuration or shape. It is a stable, non-progressive and prelingual form of hearing loss, implying that this may be a recessive form of deafness. No identifiable environmental confounding factors or associations were identified. The deafness is not linked the common known auditory gene mutations in GJB2, the GJB6-D13S1830 deletion, or the common mitochondrial mutations A1555G, A3243G, A7511C and A7445G. Severe and profound levels of hearing loss were found in 22.8% and 75% of the cohort respectively, with the majority exhibiting flat (70.1%) or sloping (23.4%) audiograms that were commonly symmetrical (81.5%). However, as indicated, there was no clear pattern in the audiological findings overall. None of the 184 hearing impaired individuals exhibited any of the reported disease causing mutations of GJB2, including 35delG. There was, however, a high prevalence of two variants, the C>T variant at position g.3318-15 and the C>T variant at position g.3318-34, occurring in 21.4% and 46.2% of the deaf cohort respectively. The same variants were found to occur in 35% and 42.6% of a normal hearing control group (n = 63) respectively, indicating that these variations are polymorphisms. In three subjects (1.63% of the cohort), a T>A homozygous variation at position g.3318-6 was detected. Its significance in the causation of NSSNHL is yet to be determined. The GJB6-D13S1830 deletion was not detected in any of the participants. None of the four mitochondrial mutations screened for were found. 4 These results indicate that GJB2 is not a significant deafness gene in the African population of the Limpopo Province of South Africa and that significant genes for non-syndromic recessive hearing loss in this population are yet to be found. The geographical clustering of deafness found in this study, combined with the lack of identifiable common associated clinical features among the subjects of this study (excluding the WS sibling pair), suggests that these subjects have a genetic recessive non-syndromal type of hearing loss. In the context of historical and cultural evidence of consanguinity in this population, a founder effect cannot be ruled out. A rare mutation, R223X, previously identified only once out of 470 WS patients, was identified in the PAX3 gene among the WS sibling pair. A novel silent change GGG>GGT at amino acid 293, was also identified. These identical findings document, for the first time, a molecular defect in WS in an African sibling pair, and confirm WS Type I in this family, which could be found in other WS type I South Africans in the Limpopo Province of South Africa. The current study demonstrated that parents of genetically hearing impaired children in these areas are able to detect hearing loss at an early age, with over 60% suspecting their children’s hearing loss below 6 months of age. A child-centered management model encompassing all the areas relevant to childhood deafness/hearing impairment, which takes into consideration the prevailing logistical and financial constraints of the available healthcare system, is proposed. The implementation of this model requires a paradigm shift from the current fragmented model of service delivery to a cohesive patient-centered approach, based on concrete data from appropriate community based research, in which all the relevant parties communicate and share resources. 5 It would achieve the goals of early detection and intervention, as well as inclusive education for all. The relevant health and education policies are already in place and the posts funded. Equitable implementation of these policies would require appropriate community based research, as well as improved communication and consultation between the various stakeholders to ensure an efficient and affordable quality healthcare service for all hearing impaired South Africans.