Sweetpotato (Ipomoea batatas (L.) Lam.) is a root crop well established throughout the world's tropical and sub-tropical regions. Despite sweepotato's importance, it has been under-researched relative to many other major crops. The main objective of this thesis is to contribute to a fuller understanding of the genetic and physiological factors underlying the production of sweetpotato storage roots for human consumption. The sweetpotato genome is diverse and subject to high levels of natural somatic mutation. Applying the AFLP (amplified fragment length polymorphism) technique allowed a direct comparison of inter and intra-cultivar DNA (deoxyribonucleic acid) base sequence variation. Analysis of the variation indicated that although sweetpotatoes are clonally propagated, clones show a lack of genetic fidelity to their source. Further, the level of genetic variation within the cultivar 'Owairaka Red' indicated the continuing emergence of distinct new strains. Plant field establishment represents the interaction of both propagation and growth phases of storage root production. A range of establishment techniques were investigated in a field trial under commercial conditions. Sprouts cut from seed roots and held for six days rather than immediate planting improved establishment as measured by growth, at little expense. Plug raised plants also improved establishment, while potentially reducing the degree of intra-cultivar genetic variation. Plant carbohydrate partitioning in three cultivars, 'Beauregard', 'Beniazuma' and 'Owairaka Red' was examined by field trial over the period of storage root growth. While cultivars differed in the proportions of dry matter partitioned to leaf, stem and root organs, the cultivar specific ratios of leaf to stem dry weight were relatively stable over time. Total storage root dry weight increased with time for all cultivars, but the distribution of storage root grades by size was cultivar specific. Within the storage roots % dry weight increased over time in all cultivars, but total sugar concentration only increased for 'Beauregard' and 'Beniazuma'. Finally, a storage root disorder called 'brown centre' curtails the temperate growing season so was investigated using low temperature storage and a field trial with various nutrition regimes. The disorder was found to be associated with susceptible germplasm, high soil nitrogen and harvest time.

Conselho Nacional de Desenvolvimento Científico e Tecnológico / O alto crescimento populacional tem desencadeado uma elevada ocupação das áreas urbanas com a expansão de edificações e estradas causando alterações no meio ambiente com a consequente minimização das áreas verdes e da infiltração de água no solo. Estes fenômenos acarretam problemas como enxurradas, inundações, aumento da temperatura local e diminuição da biodiversidade com inúmeros efeitos adversos, tanto econômicos quanto ambientais e sociais. Uma das alternativas para minimizar estes problemas é a construção de telhados verdes, que tem como uma das principais funções retardar o escoamento devido ao aumento da infiltração e retenção da água das chuvas atenuando o efeito avassalador das enchentes e das zonas de calor, principalmente em climas muito quentes, além de colaborar para recuperação de ecossistemas, através do replantio de mudas. Este projeto faz parte de um conjunto de ações integradas de cidadania e inclusão social na região hidrográfica da baixada de Jacarepaguá, especificamente envolvendo a Comunidade da Vila Cascatinha, em Vargem Grande, a fim de gerar subsídios para políticas públicas em áreas de assentamentos informais, integrado ao projeto HIDROCIDADES (CNPq, FAPERJ, FINEP), que visa a conservação da água em meios urbanos e periurbanos associado à cidadania, inclusão social e melhoria da qualidade de vida nas grandes cidades. Este trabalho utiliza uma tecnologia adaptada dos telhados verdes para edificação popular (telhado de fibrocimento) muito comum no Brasil, com o objetivo de verificar uma espécie com potencial de geração de renda (visando o social) de ecossistema regionais como restinga, em edificação; analisar o crescimento e biomassa da espécie de restinga cultivada em telhados; e avaliar qualidades das mídias em função do plantio em análise de armazenamento (retenção) de água no solo. A partir da metodologia empregada na implantação dos telhados verdes em habitações populares, os resultados obtidos são desenvolvimento da espécie Ipomoea pes caprae Brasiliensis, em três tipos de mídias de crescimento e também eficiência dessas mídias no escoamento superficial. Observou-se retenção de 69,24L de água para o bagaço de cana de açúcar e 64,7L para a fibra de coco. E foi observado também um retardo da ocorrência do pico de até 14 minutos no telhado vegetado em relação ao telhado controle (convencional). / The high rates of population growth has led to a dense occupancy of periferic urban areas with buildings and roads. This has caused changes in the environment with the consequent minimization of green areas and water infiltration into the soil. These phenomena have been favoring problems such as landslides, floods, temperature increase and local biodiversity decreasing with numerous adverse effects, both social-economic, and environmental. One alternative to minimize these problems is the construction of green roofs, which has as one of its main functions increase infiltration and retention of rainwater, alleviating the effects of floods and heat zones, especially in very hot climates, and contribute to ecosystem restoration. This research is part of a set of integrated actions of citizenship and social inclusion in the lowland of Jacarepaguá river basin, specifically involving the Community Vila Cascatinha in Vargem Grande, in order to generate support for public policy in areas of informal settlements, integrated HIDROCIDADES Project (CNPq / FAPERJ / FINEP), which aims to conserve water in urban and peri-urban areas associated with citizenship, social inclusion and the improvement of quality of life in big cities. This work uses an adapted technology for planting on roof tops of social interest habitations (fibercement tiles), very common in Brazil, aiming to verify a restinga local ecosystem species with potential for income generation increase (foccus on the social), as well as environmental compensation. It was analyzed the growth and biomass generation of the Ipomoea pes caprae Brasiliensis cultivated on roof top and assessed qualities of the growth media and its retention capacities. Retention of 69.24 liters of water on sugar cane bagasse and 64.7 L on coconut fiber applied as growth medias were observed. It was also observed a delay in the occurrence of the peak-flow of up to 14 minutes on the planted roof in comparison to the convetional roof top of fibercement tiles (non-planted).

Submitted by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-02-27T13:30:36Z No. of bitstreams: 5 50.pdf: 601131 bytes, checksum: 40ec6f06ce6ce603d177d20c34d83fbd (MD5) license_url: 52 bytes, checksum: 3d480ae6c91e310daba2020f8787d6f9 (MD5) license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) license.txt: 2109 bytes, checksum: aa477231e840f304454a16eb85a9235f (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-02-27T19:17:39Z (GMT) No. of bitstreams: 5 50.pdf: 601131 bytes, checksum: 40ec6f06ce6ce603d177d20c34d83fbd (MD5) license_url: 52 bytes, checksum: 3d480ae6c91e310daba2020f8787d6f9 (MD5) license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) license.txt: 2109 bytes, checksum: aa477231e840f304454a16eb85a9235f (MD5) / Made available in DSpace on 2015-02-27T19:17:39Z (GMT). No. of bitstreams: 5 50.pdf: 601131 bytes, checksum: 40ec6f06ce6ce603d177d20c34d83fbd (MD5) license_url: 52 bytes, checksum: 3d480ae6c91e310daba2020f8787d6f9 (MD5) license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) license.txt: 2109 bytes, checksum: aa477231e840f304454a16eb85a9235f (MD5) Previous issue date: 2012 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (Capes) / Objetivou-se selecionar gen?tipos de batata-doce mais produtivos e de melhor qualidade nutricional e avaliar a qualidade da silagem de ramas e de ra?zes de batata-doce. Foram realizados dois ensaios. Com o primeiro ensaio objetivou-se selecionar gen?tipos de batata-doce de melhores caracter?sticas de produ??o de ramas e avaliar a composi??o bromatol?gica das ramas emurchecidas de batata-doce e de suas silagens. O experimento foi conduzido na Fazenda Rio Manso, da UFVJM, em Couto Magalh?es de Minas - MG. Foi utilizado o delineamento em blocos ao acaso, com quinze gen?tipos de batata-doce: BD-31TO, BD-26, BD-13, BD-17, BD-22, BD-24, BD-54, BD-56, BD-69, BD-43, BD-44, BD-46, BD-52, BD-35 e a cultivar comercial Brazl?ndia Rosada, com tr?s repeti??es. Apenas para o n?mero de folhas por metro linear n?o foram observadas diferen?as significativas entre os gen?tipos. A maioria dos gen?tipos estudados apresenta m?dia a alta produtividade de massa verde (PMV) e de massa seca das ramas (PMS). Devido ? exist?ncia de correla??o entre o comprimento da haste principal (CH) e a PMS, pode-se em futuros trabalhos mensurar o comprimento da haste visando maiores PMS. N?o foram observadas diferen?as significativas entre os gen?tipos para os teores de carboidratos sol?veis das ramas emurchecidas e silagens das ramas. Foram encontradas diferen?as significativas para os teores de mat?ria seca (MS), cinzas, prote?na bruta (PB), fibra em detergente neutro (FDN), fibra em detergente ?cido (FDA) e lignina. Para as ramas emurchecidas, os gen?tipos BD-26, BD-13, BD-56, BD-46, BD-35 e Brazl?ndia Rosada apresentaram as composi??es bromatol?gicas mais adequadas. O n?mero de folhas na cultura da batata-doce n?o possui rela??o com a qualidade bromatol?gica de suas ramas. Para as silagens das ramas, o gen?tipo BD-56 proporcionou as melhores caracter?sticas bromatol?gicas. Com o segundo ensaio objetivou-se avaliar caracter?sticas de produtividade de ra?zes, a composi??o bromatol?gica das silagens de ra?zes e o potencial de produ??o de prote?na bruta de diferentes gen?tipos batata-doce. Foi utilizado o delineamento em blocos ao acaso, com dez tratamentos e duas repeti??es, sendo os gen?tipos de batata-doce oriundos do banco de germoplasma da UFVJM (BD-31TO, BD-17, BD-22, BD-24, BD-54, BD-69, BD-43, BD-46, BD-52 e BD-35). As parcelas foram compostas por duas leiras de 3,0 m, com 0,90 m entre leiras e 0,30 m entre plantas. Na colheita foram avaliadas as caracter?sticas de produtividade total de ra?zes (PTR) e produtividade comercial de ra?zes (PCR), n?o sendo observadas diferen?as significativas entre os gen?tipos para essas caracter?sticas. As PTR e PCR foram baixas, abaixo da m?dia nacional. Para os teores m?dios de MS, nitrog?nio amoniacal (%N-NH3 NT-1), FDN e lignina houve diferen?as significativas entre os gen?tipos avaliados. Os gen?tipos BD-17, BD-69 e BD-46 originaram silagens de raiz de melhores composi??es bromatol?gicas. A cultura da batata-doce possui alto potencial de produ??o de PB, com destaque para os gen?tipos BD-17, BD-54, BD-43, BD-46 e BD-52. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Produ??o Vegetal, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2012. / ABSTRACT The objective of this study was to select genotypes of sweet potato more productive and better nutritional quality and evaluate the quality of silage branches and roots of sweet potato. Two experiments were conducted. With the first experiment was aimed to select genotypes of sweet potato with best features of production of branches and assess the chemical composition of branches wilted sweet potato and its silages. The experiment was conducted at the Fazenda Rio Manso of the UFVJM in the city of Couto Magalh?es de Minas ? MG - Brazil. We used a randomized block design, with fifteen genotypes of sweet potato: BD-31TO, BD-26, BD-13, BD-17, BD-22, BD-24, BD-54, BD-56, BD-69, BD-43, BD-44, BD-46, BD-52, BD-35 and the commercial cultivar Brazl?ndia Rosada, with three replications. Only the number of leaves per linear meter no significant differences were observed among genotypes. Most genotypes has medium to high productivity of green mass (PGM) and dry mass of branches. Due the correlation between the length of the main branch (CB) and productivity of dry mass of branches (PDM), can in future studies to measure the length of the rod aiming higher PDM. No significant differences were observed among genotypes for soluble carbohydrates from branches and wilted silages of branches. Significant differences were found for dry matter (DM), ash, crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF) and lignin. For the wilted branches, genotypes BD-26, BD-13, BD-56, BD-46, BD-35 and Brazl?ndia Rosada presented better compositions bromatologic. The number of leaves in the culture of sweet potato has no relation with the chemical quality of their branches. For silages of branches, genotype BD-56 have the best qualitative characteristics. The second experiment aimed to evaluate characteristics of root yield, composition of silages of roots and the potential production of crude protein of sweet potato genotypes. We used a randomized block design with ten treatments and two replications, and the sweet potato genotypes from the germplasm bank of UFVJM (BD-31TO, BD-17, BD-22, BD-24, BD-54 , BD-69, BD-43, BD-46, BD-52, BD-35). The plots were composed of two piles of 3.0 m, with 0.90 m between furrows and 0.30 m between plants. At harvest, the characteristics evaluated were total root yields (TRY) and marketable yield of roots (MYR), no differences were observed among genotypes these characteristics. The TRY and MYR were low, below the national average. For the average levels of DM, ammonia nitrogen (% N-NH3.NT-1), NDF and lignin were no significant differences between genotypes. The genotypes BD-17, BD-69 and BD-46 showed the best results of composition of silages roots. The culture of sweet potato has a high potential for production of CP, especially with the genotypes BD-17, BD-54, BD-43, BD-46 and BD-52.

Conselho Nacional de Desenvolvimento Científico e Tecnológico / O alto crescimento populacional tem desencadeado uma elevada ocupação das áreas urbanas com a expansão de edificações e estradas causando alterações no meio ambiente com a consequente minimização das áreas verdes e da infiltração de água no solo. Estes fenômenos acarretam problemas como enxurradas, inundações, aumento da temperatura local e diminuição da biodiversidade com inúmeros efeitos adversos, tanto econômicos quanto ambientais e sociais. Uma das alternativas para minimizar estes problemas é a construção de telhados verdes, que tem como uma das principais funções retardar o escoamento devido ao aumento da infiltração e retenção da água das chuvas atenuando o efeito avassalador das enchentes e das zonas de calor, principalmente em climas muito quentes, além de colaborar para recuperação de ecossistemas, através do replantio de mudas. Este projeto faz parte de um conjunto de ações integradas de cidadania e inclusão social na região hidrográfica da baixada de Jacarepaguá, especificamente envolvendo a Comunidade da Vila Cascatinha, em Vargem Grande, a fim de gerar subsídios para políticas públicas em áreas de assentamentos informais, integrado ao projeto HIDROCIDADES (CNPq, FAPERJ, FINEP), que visa a conservação da água em meios urbanos e periurbanos associado à cidadania, inclusão social e melhoria da qualidade de vida nas grandes cidades. Este trabalho utiliza uma tecnologia adaptada dos telhados verdes para edificação popular (telhado de fibrocimento) muito comum no Brasil, com o objetivo de verificar uma espécie com potencial de geração de renda (visando o social) de ecossistema regionais como restinga, em edificação; analisar o crescimento e biomassa da espécie de restinga cultivada em telhados; e avaliar qualidades das mídias em função do plantio em análise de armazenamento (retenção) de água no solo. A partir da metodologia empregada na implantação dos telhados verdes em habitações populares, os resultados obtidos são desenvolvimento da espécie Ipomoea pes caprae Brasiliensis, em três tipos de mídias de crescimento e também eficiência dessas mídias no escoamento superficial. Observou-se retenção de 69,24L de água para o bagaço de cana de açúcar e 64,7L para a fibra de coco. E foi observado também um retardo da ocorrência do pico de até 14 minutos no telhado vegetado em relação ao telhado controle (convencional). / The high rates of population growth has led to a dense occupancy of periferic urban areas with buildings and roads. This has caused changes in the environment with the consequent minimization of green areas and water infiltration into the soil. These phenomena have been favoring problems such as landslides, floods, temperature increase and local biodiversity decreasing with numerous adverse effects, both social-economic, and environmental. One alternative to minimize these problems is the construction of green roofs, which has as one of its main functions increase infiltration and retention of rainwater, alleviating the effects of floods and heat zones, especially in very hot climates, and contribute to ecosystem restoration. This research is part of a set of integrated actions of citizenship and social inclusion in the lowland of Jacarepaguá river basin, specifically involving the Community Vila Cascatinha in Vargem Grande, in order to generate support for public policy in areas of informal settlements, integrated HIDROCIDADES Project (CNPq / FAPERJ / FINEP), which aims to conserve water in urban and peri-urban areas associated with citizenship, social inclusion and the improvement of quality of life in big cities. This work uses an adapted technology for planting on roof tops of social interest habitations (fibercement tiles), very common in Brazil, aiming to verify a restinga local ecosystem species with potential for income generation increase (foccus on the social), as well as environmental compensation. It was analyzed the growth and biomass generation of the Ipomoea pes caprae Brasiliensis cultivated on roof top and assessed qualities of the growth media and its retention capacities. Retention of 69.24 liters of water on sugar cane bagasse and 64.7 L on coconut fiber applied as growth medias were observed. It was also observed a delay in the occurrence of the peak-flow of up to 14 minutes on the planted roof in comparison to the convetional roof top of fibercement tiles (non-planted).

The sweet potato (Ipomoea batatas L.) is a dicotyledonous species of Convolvulaceae family, cultivated worldwide, with a low production cost and high economic return. Can be utilized in food and feed and ethanol production. The present study aimed, morphological, agronomic and biochemical characterization of sweet potato from the Active Germplasm Bank of UFS access. The experiment was conducted at the Experimental Farm " Rural Campus " UFS, located in the municipality of São Cristóvão - SE, using a randomized block design with 73 treatments (accessions of sweet potato), and two repetitions. In morpho-agronomic characterization it was found that descriptors sheet provided the variability among accessions. It was also observed that most accessions showed resistance to soil insects. The fresh and dry weight of shoots showed results ranging from 0,45 t ha-1 to 12,16 t ha-1 and 0,17 t ha-1 to 2,71 t ha-1, respectively. For total root yield variable, the values ranged from 1,20 to 10,89 t ha-1. The accessions showed excellent results for the dry root mass averaging 30,77 %. The starch content varied between 11,56 and 27,07 % , the yield of starch per hectare ranged from 0,30 to 2,39 t ha-1 and amylose content showed values between 11,57 to 32,72 %. While the ethanol yield in L ha-1 ranged from 198-1576 L h-1, the ethanol yield on L t-1 had an average of 142,67 L t-1. The results showed that the Active Germplasm Bank of UFS presents a wide phenotypic and genotypic variability, with different skills. / A batata-doce (Ipomoea batatas L.) é uma espécie dicotiledônea da família Convolvulaceae, cultivada em todo o mundo, apresentando um baixo custo de produção e retorno econômico elevado. Pode ser aproveitada na alimentação humana e animal e na produção de etanol. O presente trabalho teve como objetivo, a caracterização morfológica, agronômica e bioquímica de acessos de batata-doce do Banco Ativo de Germoplasma da UFS. O experimento foi conduzido na Fazenda Experimental Campus Rural da UFS, localizada no município de São Cristovão SE, utilizando o delineamento em blocos casualizados, com 73 tratamentos (acessos de batata-doce), e duas repetições. Na caracterização morfo-agronômica verificou-se que os descritores de folha proporcionaram a variabilidade entre os acessos. Observou-se também que a maioria dos acessos apresentou resistência a insetos de solo. A massa fresca e seca de parte aérea apresentou resultados variando de 0,45 t ha-1 a 12,16 t ha-1 e 0,17 t ha-1 a 2,71 t ha-1, respectivamente. Para a variável produtividade total de raízes, os valores variaram de 1,20 a 10,89 t ha-1. Os acessos demonstraram resultados excelentes para o teor de massa seca de raiz com média de 30,77%. O teor de amido variou entre 11,56 e 27,07%, o rendimento de amido por hectare ficou entre 0,30 a 2,39 t ha-1 e o teor de amilose apresentou valores entre 11,57 a 32,72 %. Enquanto que o rendimento de etanol em L ha-1 variou entre 198 a 1.576 L ha-1, o rendimento de etanol em L t-1 apresentou média de 142,67 L t-1. Os resultados mostraram que o Banco Ativo de Germoplasma da UFS apresenta uma grande variabilidade fenotípica e genotípica, com diferentes aptidões.

Morphological and anatomical studies demonstrated the root formation characteristics of sweet potato. The presence and importance of preformed root primordia is recorded for the first time. On the vines root primordia are present in sets of four to ten adjacent to the leaf bases. These roots originate from the procambium on both sides of the leaf gap. Macroscopically the root tips of preformed root primordia protruding through the cortex and epidermis of the stems are prominent. The preformed root primordia produce adventitious roots, with pentarch, hexarch or septarch steles. Storage roots will under normal circumstances only originate from undamaged root primordia on the nodes of cuttings, or on nodes of newly formed vines, or from wound roots originating from the cut ends of the stem or leaf cuttings. Lateral roots originating from damaged root primordia, or directly from the adventitious roots, exhibit tetrarch steles and develop into fibrous roots without the potential to develop into storage roots. This understanding of the origin, anatomy and morphology of sweet potato roots should improve production practices, which will contribute to improved crop establishment and increased yield. Differences in the contribution of individual subterranean nodes to storage root yield were studied. On average cuttings with three subterranean nodes produced 3.7 storage roots, with 33.2% on subterranean node 1, 30.0% on node 2 and 36.8% on node3. However, in terms of fresh mass of the storage roots node 1 contributed 45.4%, node 2 contributed 27.1% and node 3 contributed 27.4%. The effect of temperature (20, 24, 28 and 32oC constant), orientation of cuttings (vertical vs. horizontal) and size of cuttings (1 or 3 nodes) on the development of adventitious roots was observed in plant growth chambers. Twenty-one days after planting, the longest total root length of 4m per plant was recorded from the 24oC growth chamber. The effect of soil moisture content on early root development was investigated by wetting and equilibrating sandy soil to 100, 80, 60 and 40% of field capacity. Although the 80% of field capacity treatment resulted in the best root development, differences among treatments were small, demonstrating the capacity of cuttings to successfully establish under a range of soil moisture contents. Changes in dry mass of storage roots, stems, and leaves of three sweet potato cultivars (Awasa-83, Bareda and Falaha) were studied at Awasa and Melkassa. At the final sampling the early maturing cultivar Falaha had diverted a higher proportion of the total dry mass into storage roots at Melkassa because of the early initiation and growth of storage roots. The late maturing cultivar Awasa-83 had a smaller proportion of the total dry mass diverted into the storage roots at both locations because of late root initiation and growth. The high yielding cultivars Bareda at Melkassa, and Awasa-83 at Awasa, had higher crop growth rates and higher net assimilation rates than the other cultivars. The effects of cultivar (Kudadie, Bareda and Awasa-83), planting position (horizontal and vertical), type of planting material (terminal cuttings with and without leaves) and cutting length (20, 25 and 30 cm) on the number and yield of storage roots were quantified in field trials at Awasa and Melkassa. Cultivar Kudadie produced the highest storage root yield at both locations. Horizontal planting of cuttings resulted in the highest total storage root yield at both locations. Cutting length did not affect storage root number and yield. The effect of population density (50,000, 55,555, 75,000, and 100,000 cuttings per hectare) on the performance of the three Ethiopian sweet potato cultivars was studied at Awasa. The highest planting density consistently produced the best root yield, indicating the potential to increase yields with plant populations much higher than normally used. Early maturing cultivar Falaha produced more small and medium storage roots per plant, while the intermediate cultivar Bareda produced more large storage roots. Copyright 2003, University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. Please cite as follows: Belehu, T 2003, Agronomical and physiological factors affecting growth, development and yield of sweet potato in Ethiopia, PhD thesis, University of Pretoria, Pretoria, viewed yymmdd < http://upetd.up.ac.za/thesis/available/etd-07262004-141704 / > / Thesis (PhD (Plant Production and Soil Science))--University of Pretoria, 2005. / Plant Production and Soil Science / unrestricted

PhD (Agric) (Food Science and Technology) / Department Food Science and Technology / In recent years, there has been a lot of interest in orange fleshed sweet potato (OFSP) [Ipomoea batatas (L.) Lam] cultivar, as a cheaper source of vitamin A. In Southern Africa, reports have shown that one in every three children has deficiency in vitamin A. This study investigated the variations in β-carotene (vitamin A precursor) content among selected OFSP cultivars grown in Limpopo Province, South Africa. In addition, the study investigated the effects of location on functional properties, total carotenoids and antioxidant profile of the sweet potato flour as well as their physicochemical, functional and nutritional properties. Four (4) sweet potato cultivars [Dagga, Bophelo, Impilo (orange fleshed) and Mvuvhelo (cream fleshed)] were obtained from two locations, namely, University of Venda (Univen) agricultural experimental farm and Tshiombo irrigation scheme (Tshiombo) and analysed for pasting, functional, physicochemical and nutritional properties. The sweet potato flours from these two locations were also analysed by computed tomographic (CT) scans for flour particle density. Mineral and microstructure of OFSP flours were analysed by scanning electron microscope (SEM). All measurements, except the tristimulus L* a* b* and other colour parameters from five replicates, were performed in triplicate. Statistical analysis was performed using a one-way analysis of variance and means were separated using Duncan’s multiple range test; P < 0.05 was considered to be statistically significant. Pearson’s correlation coefficients were used to determine the correlation among functional, physicochemical, nutritional and pasting properties of sweet potato flour. β-carotene content varied significantly between the two locations from 70.98 ± 0.8 μg/g (Tshiombo) to 86.09 ± 2.0 μg/g (Univen), among cultivars from 1.71 ± 0.0 μg/g (Mvuvhelo) to 201.50 ± 1.0 μg/g (Dagga) and among orange fleshed (Dagga, Bophelo and Impilo) flours from 28.38 ± 0.2 μg/g (Impilo) to 201.50 ± 1.0 μg/g (Dagga). There was a similar trend in the contents of α-carotene to that of β-carotene from the two locations, which ranged from 0.63 ± 0.0 mol/L (Tshiombo) to 1.01 ± 0.0 mol/L (Univen). Mvuvhelo had significantly the lowest α-carotene content (0.50 ± 0.0 mol/L) and Impilo the highest (1.28 ± 0.0 mol/L). The total carotenoids was highest for Impilo (7.56 μg/g) and lowest for Mvuvhelo (1.33 ± 0.1 μg/g) but did not vary significantly (P > 0.05) between ii the locations. The antioxidant activity, based on 2, 2-diphenyl-1picrylhydrazyl (DPPH) free radical scavenging activity, was significantly highest in Bophelo (63.37 ± 0.8 mMAAE ml-1) and lowest in Dagga (26.93 ± 1.4 mMAAE ml-1) flours. The ferric reducing antioxidant power (FRAP) varied significantly across the locations and among the cultivars and ranged from 14.45 ± 0.3 μMTE ml-1 (Tshiombo) to 17.40 ± 1.1 μMTE ml-1 (Univen). FRAP was significantly highest in Impilo (21.12 ± 2.1 μMTE ml-1) and lowest in Mvuvhelo (8.16 ± 2.0 μMTE ml-1). Total carotenoid content positively correlated with DPPH (0.486*), FRAP (0.830**), β-carotene (0.370*), and α-carotene (0.424*). The antioxidant content and the radical scavenging activity were significantly correlated (0.563**). Vitamin A content was significantly lowest (6.88 ± 0.38 μg/g retinol) in Dagga flour and highest (7.97 ± 0.25 μg/g) in Impilo flour. Protein content varied significantly across the two locations and ranged from 4.23% (Tshiombo) to 7.16% (Univen). Dagga had significantly the lowest (3.47%) protein content while Impilo had the highest (7.53%). The fat content of the flours varied significantly between the two locations ranging from 0.63% (Tshiombo) to 1.01% (Univen). The protein content was positively correlated 0.594** and 0.421* to vitamin A and fat contents respectively. The Bophelo colour luminosity was significantly lower (L* 76.2) than the other two OFSP, Dagga (L* 83.51) and Impilo (L* 82.07). Bophelo a* (14.09) also differed significantly across all sweet potato cultivars. All cultivars differed significantly in b* values. Colour intensity (ΔE*) ranged from 15.87 to 38.48 for Mvuvhelo and Bophelo, respectively. Chroma ranged from 87.52 to 84.95 for Dagga and Mvuvhelo respectively. Total starch content was significantly different in all sweet potato cultivars and ranged from 244.07 μg/100 g (Bophelo) to 325.04 mg/g (Dagga). Resistant starch differed significantly in all sweet potato cultivars ranging from 1.21 μg/100 g dwb (Bophelo) to 7.07 μg/100 g dwb (Impilo). Ash content was significantly different in all cultivars and ranged from 3.17% (Dagga) to 3.79% (Bophelo). Water holding capacity (WHC) varied significantly across the two locations and ranged from 1.44 g H2O/g DM (Tshiombo) to 1.72 g H2O/g DM (Univen). Bophelo had significantly the lowest (1.27 g H2O/g DM) WHC and Impilo the highest (1.99 g H2O/g DM). The ash content negatively correlated to total starch (-0.928**) but positively iii correlated to WHC (0.654**). Peak viscosity differed significantly across all cultivars under study and ranged from 126.54 RVU (Bophelo) to 302.36 RVU. (Dagga). There was significant difference in trough viscosity across all cultivars ranging from 55.97 RVU (Impilo) to 280.78 RVU (Dagga). There were significant differences in the final viscosity across all cultivars ranging from 78.99 RVU (Impilo) to 319.26 (Dagga). Peak time viscosity varied significantly across all cultivars ranging from 3.87 min (Impilo) to 8.47 min. (Bophelo). Dagga cultivar had significantly the highest pasting temperature (94.16oC) and Bophelo the lowest (77.75oC). The setback viscosity was significantly highest 51.10 RVU (Mvuvhelo) and lowest 23.01 RVU (Impilo). All cultivars from the two locations consistently showed high potassium content ranging from 0.46% (Impilo) to 1.38% (Dagga) as compared to other minerals such as magnesium, calcium and chlorine which ranged from 0.16% (Impilo) to 0.34%. (Dagga). The CT scans revealed that there was a possibility of evaluating the effect of location on the density of granules of sweet potato flour and also the inherent differences in granular distribution of various sweet potato cultivars. SEM revealed high amounts of potassium, magnesium and chlorine. A profile of physicochemical and functional properties of flour of some of the OFSP cultivars produced in Limpopo province, South Africa has been drawn. This study also highlights the nutritional quality of the flour from four sweet potato cultivars and provides a ranking of flour to help the producers in the selection process. Bophelo flour was ranked the highest in terms of β- and, α-carotenes, total carotenoids and antioxidant capacity while Impilo was ranked highest in terms of functional properties and ash content. This study has highlighted significant differences in a number of parameters measured among the sweet potato cultivars. Therefore, in order to derive the maximum benefit from aIn recent years, there has been a lot of interest in orange fleshed sweet potato (OFSP) [Ipomoea batatas (L.) Lam] cultivar, as a cheaper source of vitamin A. In Southern Africa, reports have shown that one in every three children has deficiency in vitamin A. This study investigated the variations in β-carotene (vitamin A precursor) content among selected OFSP cultivars grown in Limpopo Province, South Africa. In addition, the study investigated the effects of location on functional properties, total carotenoids and antioxidant profile of the sweet potato flour as well as their physicochemical, functional and nutritional properties. Four (4) sweet potato cultivars [Dagga, Bophelo, Impilo (orange fleshed) and Mvuvhelo (cream fleshed)] were obtained from two locations, namely, University of Venda (Univen) agricultural experimental farm and Tshiombo irrigation scheme (Tshiombo) and analysed for pasting, functional, physicochemical and nutritional properties. The sweet potato flours from these two locations were also analysed by computed tomographic (CT) scans for flour particle density. Mineral and microstructure of OFSP flours were analysed by scanning electron microscope (SEM). All measurements, except the tristimulus L* a* b* and other colour parameters from five replicates, were performed in triplicate. Statistical analysis was performed using a one-way analysis of variance and means were separated using Duncan’s multiple range test; P < 0.05 was considered to be statistically significant. Pearson’s correlation coefficients were used to determine the correlation among functional, physicochemical, nutritional and pasting properties of sweet potato flour. β-carotene content varied significantly between the two locations from 70.98 ± 0.8 μg/g (Tshiombo) to 86.09 ± 2.0 μg/g (Univen), among cultivars from 1.71 ± 0.0 μg/g (Mvuvhelo) to 201.50 ± 1.0 μg/g (Dagga) and among orange fleshed (Dagga, Bophelo and Impilo) flours from 28.38 ± 0.2 μg/g (Impilo) to 201.50 ± 1.0 μg/g (Dagga). There was a similar trend in the contents of α-carotene to that of β-carotene from the two locations, which ranged from 0.63 ± 0.0 mol/L (Tshiombo) to 1.01 ± 0.0 mol/L (Univen). Mvuvhelo had significantly the lowest α-carotene content (0.50 ± 0.0 mol/L) and Impilo the highest (1.28 ± 0.0 mol/L). The total carotenoids was highest for Impilo (7.56 μg/g) and lowest for Mvuvhelo (1.33 ± 0.1 μg/g) but did not vary significantly (P > 0.05) between ii the locations. The antioxidant activity, based on 2, 2-diphenyl-1picrylhydrazyl (DPPH) free radical scavenging activity, was significantly highest in Bophelo (63.37 ± 0.8 mMAAE ml-1) and lowest in Dagga (26.93 ± 1.4 mMAAE ml-1) flours. The ferric reducing antioxidant power (FRAP) varied significantly across the locations and among the cultivars and ranged from 14.45 ± 0.3 μMTE ml-1 (Tshiombo) to 17.40 ± 1.1 μMTE ml-1 (Univen). FRAP was significantly highest in Impilo (21.12 ± 2.1 μMTE ml-1) and lowest in Mvuvhelo (8.16 ± 2.0 μMTE ml-1). Total carotenoid content positively correlated with DPPH (0.486*), FRAP (0.830**), β-carotene (0.370*), and α-carotene (0.424*). The antioxidant content and the radical scavenging activity were significantly correlated (0.563**). Vitamin A content was significantly lowest (6.88 ± 0.38 μg/g retinol) in Dagga flour and highest (7.97 ± 0.25 μg/g) in Impilo flour. Protein content varied significantly across the two locations and ranged from 4.23% (Tshiombo) to 7.16% (Univen). Dagga had significantly the lowest (3.47%) protein content while Impilo had the highest (7.53%). The fat content of the flours varied significantly between the two locations ranging from 0.63% (Tshiombo) to 1.01% (Univen). The protein content was positively correlated 0.594** and 0.421* to vitamin A and fat contents respectively. The Bophelo colour luminosity was significantly lower (L* 76.2) than the other two OFSP, Dagga (L* 83.51) and Impilo (L* 82.07). Bophelo a* (14.09) also differed significantly across all sweet potato cultivars. All cultivars differed significantly in b* values. Colour intensity (ΔE*) ranged from 15.87 to 38.48 for Mvuvhelo and Bophelo, respectively. Chroma ranged from 87.52 to 84.95 for Dagga and Mvuvhelo respectively. Total starch content was significantly different in all sweet potato cultivars and ranged from 244.07 μg/100 g (Bophelo) to 325.04 mg/g (Dagga). Resistant starch differed significantly in all sweet potato cultivars ranging from 1.21 μg/100 g dwb (Bophelo) to 7.07 μg/100 g dwb (Impilo). Ash content was significantly different in all cultivars and ranged from 3.17% (Dagga) to 3.79% (Bophelo). Water holding capacity (WHC) varied significantly across the two locations and ranged from 1.44 g H2O/g DM (Tshiombo) to 1.72 g H2O/g DM (Univen). Bophelo had significantly the lowest (1.27 g H2O/g DM) WHC and Impilo the highest (1.99 g H2O/g DM). The ash content negatively correlated to total starch (-0.928**) but positively iii correlated to WHC (0.654**). Peak viscosity differed significantly across all cultivars under study and ranged from 126.54 RVU (Bophelo) to 302.36 RVU. (Dagga). There was significant difference in trough viscosity across all cultivars ranging from 55.97 RVU (Impilo) to 280.78 RVU (Dagga). There were significant differences in the final viscosity across all cultivars ranging from 78.99 RVU (Impilo) to 319.26 (Dagga). Peak time viscosity varied significantly across all cultivars ranging from 3.87 min (Impilo) to 8.47 min. (Bophelo). Dagga cultivar had significantly the highest pasting temperature (94.16oC) and Bophelo the lowest (77.75oC). The setback viscosity was significantly highest 51.10 RVU (Mvuvhelo) and lowest 23.01 RVU (Impilo). All cultivars from the two locations consistently showed high potassium content ranging from 0.46% (Impilo) to 1.38% (Dagga) as compared to other minerals such as magnesium, calcium and chlorine which ranged from 0.16% (Impilo) to 0.34%. (Dagga). The CT scans revealed that there was a possibility of evaluating the effect of location on the density of granules of sweet potato flour and also the inherent differences in granular distribution of various sweet potato cultivars. SEM revealed high amounts of potassium, magnesium and chlorine. A profile of physicochemical and functional properties of flour of some of the OFSP cultivars produced in Limpopo province, South Africa has been drawn. This study also highlights the nutritional quality of the flour from four sweet potato cultivars and provides a ranking of flour to help the producers in the selection process. Bophelo flour was ranked the highest in terms of β- and, α-carotenes, total carotenoids and antioxidant capacity while Impilo was ranked highest in terms of functional properties and ash content. This study has highlighted significant differences in a number of parameters measured among the sweet potato cultivars. Therefore, in order to derive the maximum benefit from a given cultivar careful selection of sweet potato cultivars would be necessary.

Thesis (M. Tech. (Biomedical Technology)) -- Central University of Technology, Free State, 2014. / Traditional medicine has been known by mankind since ancient times as a healthcare system. All cultures have used herbs throughout history and it was an integral part of the development of modern civilization. Primitive man observed and appreciated the great diversity of plants available to him. Plants provided food, clothes, shelter and medicine and still play a vital role in rural villages of South Africa. The medicinal uses of plants and animals have been developed through trial and error. Herbal plants produce and contain a wide variety of chemical substances that act upon the body’s immune system. The medicinal properties of Ipomoea oblongata (E.Mey.ex Choisy) in this study was to determine the phytochemical content, antioxidant, anti-cancer and anti-diabetic properties of I. oblongata (Mothokho), a medicinal plant used by traditional medical practitioners of Thaba-Nchu in the Free State. The study was carried out in order to validate the ethnomedicinal claims made by the traditional medical practitioners and to evaluate the plant’s potential as a novel therapeutic agent. Twelve traditional medical practitioners of the Kopanang Dingaka Association were interviewed on the knowledge and use of I. oblongata (Mothokho). The phytochemical constituents of the plant were determined using standard screening methods. Testing for antioxidant properties (free radical scavenging activity) was carried out by means of the 2, 2- diphenylpicrylhydrazyl (DPPH) assays. The Sulforhodamine B assay was used to screen for anti-cancer activity in breast (MCF7), colon (HCT116) and prostate (PC3) cancer cell lines. Glucose uptake in C2C12 muscle cells was used to evaluate the anti- iii diabetic potential of I. oblongata. Methanol extract was fractionated using Ultra-Pure Liquid Chromatography (UPLC) to identify active compounds. The traditional medical practitioners cited the plant roots as the main ingredient in the treatment of respiratory infections, sexually transmitted infections, postnatal womb treatments, inflammation, arthritis, wounds and cancer. The methanol extract of I. oblongata showed remarkable (99.03%, 98.39, 71.31%) antioxidant potential in all triplicates tested which explains its use in oxidative stress-related diseases such as arthritis and cancer. Phytochemical tests showed the presence of carbohydrates, glycosides, steroids, terpenoids, alkaloids, flavonoids and tannins. However, the extracts were inactive against the cancer cell lines used. Glucose uptake by the C2C12 muscle cells was increased by over 150% and was comparable to that of insulin and metformin, suggesting good anti-diabetic activity. Predicted compounds found were dihydroquercetin pentaacetate, actinorhodin and actinorhodine, using Chemspider analysis. These are possible compounds that could be found in the Ipomoea oblongata extracts when using nuclear magnetic resonance (NMR) to determine the structure and names of the active compounds. Ethnobotanical uses of Ipomoea oblongata were found to have a link with other ethnobotanical studies to capture the indigenous knowledge, culture and therapeutic uses. The phytochemical results of Ipomoea oblongata can contribute to the knowledge of new drug development as indicated by literature (Harbone; 1973, Soforowa, 1993; De et al., 2010) that plants contain phytochemical contents and phenolic compounds that are valuable as medicinal properties. Methanolic extract of Ipomoea oblongata presented high levels of antioxidant activity respectively, which can become a potential iv antimicrobial agent and remedy oxidative stress related diseases. The anticancer properties were inactive and the cytotoxicity levels were found to below in I. oblongata. Low levels of cytotoxicity allow medicinal plants to be consumed by humans with fewer side effects however doses must be standardized. High levels of glucose uptake in muscle cells were indicated from the aqueous extract of Ipomoea oblongata, therefore showing great potential as an antidiabetic agent. Many medicinal plants have been validated as antidiabetic therapeutic agents in South Africa and the world. New treatment of cancer, diabetes, bacterial and viral infections is required from natural products that are cost effective with minimal side effects that can be used in health care systems. There is a correlation between the medicinal properties found in I. oblongata and the ethnomedicinal uses cited by the traditional medical practitioners. The plant I. oblongata has six ethno-pharmaceutical uses. I. oblongata is a good source of anti-diabetic and antioxidant agents that can be developed further. However the plant is not a good source of anticancer properties. Future research will be into the isolation and identification of the active compounds.

Field studies were conducted during 2006 and 2007 to evaluate control of saw greenbriar and southern dewberry by various pasture herbicides and to assess forage tolerance of Tifton 85 bermudagrass to these herbicides. Herbicides evaluated in each study included triclopyr, picloram, 2,4-D, fluroxypyr, dicamba, aminopyralid, metsulfuron methyl and various combinations of the above. Visual ratings were taken on each herbicide efficacy experiment. Visual evaluations of phytotoxicity, measurements of dry matter yield, and forage quality were quantified for each of the bermudagrass tolerance trials. Saw greenbriar was best controlled at approximately one year after treatment by triclopyr at 10.9% ae v/v with diesel as the carrier (88-98%), although the lower rate of triclopyr + diesel at 0.87% ae v/v + 5% v/v and triclopyr alone at 0.87% ae v/v provided 49 to 86% control. Triclopyr + fluroxypyr at 0.25% ai v/v + 0.086% ai v/v gave best control of southern dewberry in both years when applied as an individual plant treatment (IPT) six weeks after shredding. In general, shredding 45 days prior to herbicide application gave an advantage to southern dewberry control versus not shredding. In 2006, triclopyr + fluroxypyr (IPT) was the only treatment to decrease Tifton 85 dry matter yield at the first harvest, with no effect observed at the second harvest. In 2007, both broadcast treatments containing triclopyr + fluroxypyr and the IPT treatment of triclopyr decreased dry matter yield at the first harvest, with triclopyr (IPT) being the only treatment to lower dry matter yield at the second harvest. Field studies were also conducted in 2006 and 2007 to assess sharppod morningglory control in Roundup Ready Flex® and LibertyLink® cotton systems. Herbicides evaluated included glyphosate, glufosinate, prometryn, fluometuron, and diuron. Visual ratings of percent weed control and sharppod morningglory plant counts were taken to assess control. Prometryn at 1.8 kg ai ha⁻¹ and fluometuron at 1.8 kg ai ha⁻¹ provided significant preemergence control (33-81%) of seedling sharppod morningglory. All rates of glyphosate (1.06 and 1.54 kg ai ha⁻¹) and glufosinate (0.45 and 0.6 kg ai ha⁻¹) controlled sharppod morningglory from 55 to 100% at both application timings. The addition of diuron at 1.12 kg ai ha⁻¹ to glyphosate and glufosinate at the late season application enhanced sharppod morningglory control by 3 to 16%. Additionally, in both years, no reduction in cotton yield was observed in the morningglory infested treatment when compared to the weed free treatment.

<p dir="ltr">Sweetpotato (<i>Ipomoea batatas</i> L.) is a staple crop that provides nutritional benefits to humans globally, but it is subjected to yield loss when competing with weeds, especially during the early stage of establishment. Despite increased organic sweetpotato production in the United States, growers face challenges with limited weed management options and often resort to time-consuming and costly cultivation and hand-weeding. To address this challenge, experiments were developed to determine (1) the effect of sweetpotato cultivar on the critical weed-free period, (2) the effects of in-row plant spacing and cultivar selection on weed suppression and sweetpotato yield, and (3) the impact of buckwheat and silage tarps for row-middle weed control. 1) In 2022, field research was conducted at the Samuel G. Meigs Horticulture Research Farm (Meigs), Lafayette, IN, and at the Southwest Purdue Agricultural Center (SWPAC), Vincennes, IN to estimate the critical weed-free period for ‘Covington’, ‘Murasaki’, and ‘Monaco’ in the Midwest. The experiment was a split-plot design, with weed-free interval treatments as the main plot factor and cultivar as the subplot factor. Weeds were removed by hand and allowed to establish and compete with the crop beginning at 0, 14, 21, 28, 35, or 42 days after transplanting (DAP). As weed-free interval increased from 0 to 42 DAP, predicted total yield increased from 19 kg ha^-1 to 20,540 kg ha^-1for Covington, 3 kg ha^-1 to 11,407 kg ha^-1 for Monaco, and 125 kg ha^-1to 13,460 kg ha^-1for Murasaki at the Lafayette location. A threshold of ≤10% total yield reduction was achieved by maintaining sweetpotatoes weed-free 24 DAP for Covington, 20 DAP for Murasaki, and 33 DAP for Monaco. 2) In 2022 and 2023, studies were conducted at Meigs, Lafayette, IN and SWPAC, Vincennes, IN to evaluate in-row plant spacing and cultivars for weed control and sweetpotato yield. The experiment was a split-split plot design, with in-row spacings of 20, 30, and 40 cm as the main plot factor, weeding frequency (‘critical weed-free period’ and ‘weed free’) as the subplot factor, and sweetpotato cultivar (‘Covington’ and ‘Monaco’) as the sub-subplot factor. However, in 2022, we evaluated only in-row spacing and weeding frequency because of poor establishment of Monaco. In-row spacing had no significant effect on weed densities at 4, 5, and 6 WAP. As in-row spacing increased from 20 to 40 cm, total sweetpotato yield pooled across both locations in 2023 decreased from 30,223 to 21,209 kg ha^-1 for Covington and 24,370 to 20,848 kg ha^-1 for Monaco, however, jumbo yield increased for both cultivars. Findings from this study suggest that an in-row spacing of 20 cm may provide greater yield than the standard spacing, 30 cm, for both Monaco and Covington cultivars and could reduce weed interference through more rapid sweetpotato canopy closure. 3) The experiment was a randomized complete block design, with three row-middle treatments [tarp, buckwheat, and cultivation] and four replicates. Row-middle treatments were established immediately after transplanting ‘Covington’ slips 30 cm apart into raised bed plots consisting of a single row 6 m long and 2 m apart on-center. Buckwheat was planted three weeks after transplanting (WAP) at a rate of 108 kg ha^-1 in row-middle. Row-middles for the tarp treatment were covered for the entire growing season. Weed density at 6 WAP was 184 plants m^-2 for the buckwheat, and 162 plants m^-2 for the cultivation treatments. Total yield was 11,050 kg ha^-1 for the buckwheat, 19,790 kg ha^-1 for the cultivation, and 17,810 kg ha^-1 for the tarping treatments. Tarping effectively suppressed weeds and produced sweetpotato yields comparable to cultivation indicating potential for organic growers. Buckwheat yields were lower than those from tarping and cultivation.</p>