Agro-morphological characterization and investigations into the response of yellow Quality Protein Maize (QPM) genotypes to low soil pH
- Authors: Bobotyana, Simthandile
- Date: 2021-04
- Subjects: Corn as food , Plants--Drought tolerance
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20528 , vital:46087
- Description: Maize (Zea mays L) is an essential food grain crop in South Africa and is mainly grown under rainfed conditions by small-scale farmers. Quality Protein Maize (QPM) contains a higher level of two essential amino acids, tryptophan, and lysine when equated to normal maize. Therefore, the QPM in communities is a vital cereal where maize is a staple crop. Among the significant abiotic stresses that adversely affect maize productivity, such as soil fertility. Low soil pH or soil acidity results in nutrient deficiencies, as well as the toxicity of minerals such as manganese (Mn), aluminium (Al), and iron (Fe). The objectives of the study were to: (1) Characterize yellow QPM inbred lines and testcross hybrids for agro-morphological variability under optimum conditions, (2) Determine the response of QPM inbred lines and testcross hybrids to Al toxicity, and (3) Estimate the combining ability of QPM genotypes for the tolerance to Al toxicity. The laboratory assessment for tolerance to Al toxicity revealed a negative relationship between relative root growth RRG and hematoxylin staining; among the inbred lines, the genotype 8Y, 17Y, and 7Y had the highest RRG and net root growth (NRG) values and exhibited the highest tolerance to Al tolerance with the least hematoxylin staining. Inbred lines 12Y, 16Y, 19Y, 2Y, 20Y, 24Y, 30Y, 27Y, 34Y, 4Y, and 11Y were moderately tolerant. On the other hand, inbred lines 13Y, 18Y, and QSY5 had the least RRG were susceptible. Forty-four testcross hybrids were generated by crossing 22 QPM inbred lines with two open-pollinated variety (OPV) testers. These hybrids were evaluated together with five checks for different agronomic traits. The hybrids were planted in the summer season of 2017/18 and 2018/19 under rain-fed conditions 7 x 7 alpha lattice design was used. The significant variations among the genotypes for grain yield and most other agronomic traits under optimum, acidic conditions and across environments on combined analysis of variance. The hybrid was 14Y x NC (3.22 t/ha), followed by QSY5 x NC (3.02 t/ha) showed the highest yielding. The mean plant height was 226.23 cm, with ranges 197.60 to 254.85cm. The number of kernels per ear was 35, with a range from 29.45 to 40.25. Conversely, the mean ear length was 19.30 cm with a range of 17.65 to 20.95 cm, and the mean ear diameter ranged from 13,50 to 16,05 cm. The highest yielding hybrid, according to ranking, was 14Y x NC (2,93t/ha), which was ranked number 3, followed by 3Y x NC (2,83 t/ha), which was ranked number 4. Twenty-two yellow QPM inbred lines were evaluated for agro-morphological characteristics. A randomized complete block design with three replicates was used under acidic and normal soil conditions at two locations. The mean performance of inbred lines for grain yield ranged from 1.6 t/ha to 3.1 t/ha under optimum conditions, whereas it ranged from 1.1.t/ha to 1.7 t/ha under an acidic environment. The highest grain yielding genotypes under the optimum environment were 14Y, 7Y, and QSY5, while, in the acidic environment, the highest yielders were 3Y, QSY5, and 17Y. The lowest grain yielder under the optimum environment was 16Y at 1.5 t/ha, whereas 6Y, 7Y, 8Y, and 29Y were the most moderate yielders under the acidic environment. Grain yield displayed positive and significant (p<0,05) correlation with ear height (0.59), plant height (0.55), leaf length (0.18), number of leaves (0.37), number of ears per plot (0,54), number of kernels per row, number of rows per ear and thousand kernel weight. Combined ANOVA revealed that the environment effect was significant for all traits except the number of rows per ear and the number of ears in both environments. A total of 71 genotypes (22 inbred lines, forty-four single crosses, and five checks) were evaluated using a 7 x 7 alpha lattice design with two replications in combining ability. Across environments, the analysis showed a mean grain yield record of hybrids that ranged from 1.78 t/ha to 3.42 t/ha. Combined analysis showed only about 4 percent of the 44 hybrids had better grain yield than hybrid checks, whereas about 11 percent of the 44 hybrids had higher grain yield than two of the five hybrid checks. The highest yielding hybrid was 14Y x NC followed by QSY5 x NC. The Mid-parent heterosis (MPH) for grain yield ranged from -32.70 for 11YxObat to 16.50 percent for 14YxNC among the top-yielding genotypes. The highest positive mid-parent heterosis (MPH) for grain yield was observed in hybrid 14YxNC followed by QSY9xNC, QSY5xOBAT, 3YxNC, 13YxNC and 4YxOBAT, while the remaining hybrids exhibited negative estimates. Inbred lines' proportional contributions to the total variances were much higher than the testers for all traits. Whereas the inbred lines' proportional contribution was lower than the interaction of line x tester except on the number of ears which displayed the highest estimates of variances due to SCA effects, significant variation was observed. The GCA effects on grain yield in both environments generally showed no significant difference among inbred lines except for inbred lines such as QSY5 and 34Y but were positive. The selected crosses showed significant SCA effects in a few agronomic yield-related traits in the combined analysis. Among the hybrids, the only crosses that showed significant and positive SCA effects for grain yield were 25YxNC under optimum and 34YxObat under acidic environment. The inbred lines were assessed for tolerance to Al toxicity under laboratory conditions. Overall, the study identified soil acidity tolerant QPM inbred lines with an excellent combining ability for high-yielding QPM test hybrids, grain yield, and related traits. , Thesis (MSc) (Agriculture, Crop Science) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Bobotyana, Simthandile
- Date: 2021-04
- Subjects: Corn as food , Plants--Drought tolerance
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20528 , vital:46087
- Description: Maize (Zea mays L) is an essential food grain crop in South Africa and is mainly grown under rainfed conditions by small-scale farmers. Quality Protein Maize (QPM) contains a higher level of two essential amino acids, tryptophan, and lysine when equated to normal maize. Therefore, the QPM in communities is a vital cereal where maize is a staple crop. Among the significant abiotic stresses that adversely affect maize productivity, such as soil fertility. Low soil pH or soil acidity results in nutrient deficiencies, as well as the toxicity of minerals such as manganese (Mn), aluminium (Al), and iron (Fe). The objectives of the study were to: (1) Characterize yellow QPM inbred lines and testcross hybrids for agro-morphological variability under optimum conditions, (2) Determine the response of QPM inbred lines and testcross hybrids to Al toxicity, and (3) Estimate the combining ability of QPM genotypes for the tolerance to Al toxicity. The laboratory assessment for tolerance to Al toxicity revealed a negative relationship between relative root growth RRG and hematoxylin staining; among the inbred lines, the genotype 8Y, 17Y, and 7Y had the highest RRG and net root growth (NRG) values and exhibited the highest tolerance to Al tolerance with the least hematoxylin staining. Inbred lines 12Y, 16Y, 19Y, 2Y, 20Y, 24Y, 30Y, 27Y, 34Y, 4Y, and 11Y were moderately tolerant. On the other hand, inbred lines 13Y, 18Y, and QSY5 had the least RRG were susceptible. Forty-four testcross hybrids were generated by crossing 22 QPM inbred lines with two open-pollinated variety (OPV) testers. These hybrids were evaluated together with five checks for different agronomic traits. The hybrids were planted in the summer season of 2017/18 and 2018/19 under rain-fed conditions 7 x 7 alpha lattice design was used. The significant variations among the genotypes for grain yield and most other agronomic traits under optimum, acidic conditions and across environments on combined analysis of variance. The hybrid was 14Y x NC (3.22 t/ha), followed by QSY5 x NC (3.02 t/ha) showed the highest yielding. The mean plant height was 226.23 cm, with ranges 197.60 to 254.85cm. The number of kernels per ear was 35, with a range from 29.45 to 40.25. Conversely, the mean ear length was 19.30 cm with a range of 17.65 to 20.95 cm, and the mean ear diameter ranged from 13,50 to 16,05 cm. The highest yielding hybrid, according to ranking, was 14Y x NC (2,93t/ha), which was ranked number 3, followed by 3Y x NC (2,83 t/ha), which was ranked number 4. Twenty-two yellow QPM inbred lines were evaluated for agro-morphological characteristics. A randomized complete block design with three replicates was used under acidic and normal soil conditions at two locations. The mean performance of inbred lines for grain yield ranged from 1.6 t/ha to 3.1 t/ha under optimum conditions, whereas it ranged from 1.1.t/ha to 1.7 t/ha under an acidic environment. The highest grain yielding genotypes under the optimum environment were 14Y, 7Y, and QSY5, while, in the acidic environment, the highest yielders were 3Y, QSY5, and 17Y. The lowest grain yielder under the optimum environment was 16Y at 1.5 t/ha, whereas 6Y, 7Y, 8Y, and 29Y were the most moderate yielders under the acidic environment. Grain yield displayed positive and significant (p<0,05) correlation with ear height (0.59), plant height (0.55), leaf length (0.18), number of leaves (0.37), number of ears per plot (0,54), number of kernels per row, number of rows per ear and thousand kernel weight. Combined ANOVA revealed that the environment effect was significant for all traits except the number of rows per ear and the number of ears in both environments. A total of 71 genotypes (22 inbred lines, forty-four single crosses, and five checks) were evaluated using a 7 x 7 alpha lattice design with two replications in combining ability. Across environments, the analysis showed a mean grain yield record of hybrids that ranged from 1.78 t/ha to 3.42 t/ha. Combined analysis showed only about 4 percent of the 44 hybrids had better grain yield than hybrid checks, whereas about 11 percent of the 44 hybrids had higher grain yield than two of the five hybrid checks. The highest yielding hybrid was 14Y x NC followed by QSY5 x NC. The Mid-parent heterosis (MPH) for grain yield ranged from -32.70 for 11YxObat to 16.50 percent for 14YxNC among the top-yielding genotypes. The highest positive mid-parent heterosis (MPH) for grain yield was observed in hybrid 14YxNC followed by QSY9xNC, QSY5xOBAT, 3YxNC, 13YxNC and 4YxOBAT, while the remaining hybrids exhibited negative estimates. Inbred lines' proportional contributions to the total variances were much higher than the testers for all traits. Whereas the inbred lines' proportional contribution was lower than the interaction of line x tester except on the number of ears which displayed the highest estimates of variances due to SCA effects, significant variation was observed. The GCA effects on grain yield in both environments generally showed no significant difference among inbred lines except for inbred lines such as QSY5 and 34Y but were positive. The selected crosses showed significant SCA effects in a few agronomic yield-related traits in the combined analysis. Among the hybrids, the only crosses that showed significant and positive SCA effects for grain yield were 25YxNC under optimum and 34YxObat under acidic environment. The inbred lines were assessed for tolerance to Al toxicity under laboratory conditions. Overall, the study identified soil acidity tolerant QPM inbred lines with an excellent combining ability for high-yielding QPM test hybrids, grain yield, and related traits. , Thesis (MSc) (Agriculture, Crop Science) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-04
Antibiotics combination therapy option for the control of antimicrobial-resistant non-cholera causing Vibrio species recovered from environmental niches of Eastern Cape, South Africa
- Authors: Ayodele, Oluwakemi Victoria
- Date: 2021-04
- Subjects: Drug resistance in microorganisms , Vibrio cholerae
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20396 , vital:45661
- Description: Increased rate of antibiotic resistance (AR) poses a serious threat with a resultant notion of a possible end of the antibiotics era, making it a problem of concern to public health and a great implication on the world economy and human society. Despite many approaches developed to curb this menace, antibiotics resistance is still a challenge worldwide. This has made the use of combined therapy as one of the options in many cases. This study was conducted to assess antibiotics combination therapy as an option for the control of antimicrobial-resistant non-cholera causing Vibrio species that were recovered from the environment in the Eastern Cape, South Africa. Two hundred and twenty-eight Vibrio species were recovered from the environment in the Province, and these were deposited in the archive of AEMREG. PCR was used to identify target Vibrio species. Disc diffusion method was used to evaluate the antibiotic susceptibility profile of the confirmed isolates against 11 antibiotics commonly used against infections. MIC and MBC were determined using antibiotics (imipenem, tetracycline, and nalidixic acid) that high resistance was discovered. Checkerboard assay was used to carry out antibiotics combination assay, and the FICI was calculated. Rate of kill was also determined using ½ × MIC, 1 × MIC, and 2 × MIC concentrations of the combined antibiotics at 2 hr intervals. One hundred of the isolates were confirmed to be Vibrio parahaemolyticus, 82 were Vibrio vulnificus and 46 were Vibrio fluvialis. Twenty-two (22) percent of the Vibrio parahaemolyticus isolates showed resistance against tetracycline and their resistance against other antimicrobials is as follows; nalidixic acid (16 percent), ampicillin (14 percent), cefotaxime (14 percent), chloramphenicol (12 percent) and amikacin (11 percent). For Vibrio vulnificus, prevalence of resistance was as follows: imipenem (40 percent), tetracycline (22 percent), ampicillin (18 percent), meropenem (15 percent), and chloramphenicol (11 percent). Vibrio fluvialis showed the following resistance profile: nalidixic acid (28 percent), tetracycline (28percent), ampicillin (20 percent), chloramphenicol (15 percent), amikacin (11 percent) and cefotaxime (11 percent). About 38 multiple antibiotic resistance phenotypes (MARP) were recorded in all species that were evaluated. About 23 percent were resistant to over 3 antibiotics used. The multiple antibiotic resistant indices (MARI) ranged between 0.3 and 0.8. MIC and MBC were carried against isolates that were resistant to the two most common antibiotics tested. MIC and MBC were determined in the following order: tetracycline and nalidixic acid at concentrations ranging from 16 μg/ml to 1024 μg/ml for Vibrio parahaemolyticus and 32 μg/ml to 2048 μg/ml for Vibrio fluvialis. Also, the MIC and MBC of imipenem and tetracycline at concentrations ranging from 8 μg/ml to 256 μg/ml for Vibrio vulnificus were determined. Antibiotics combination therapy was carried out and synergistic activity was observed in 3 of the 16 resistant V. parahaemolyticus isolates, 3 of the16 resistant V. vulnificus isolates and 2 of the 13 resistant V. fluvialis isolates. Antagonism was not observed across all the drug combinations. Rate of kill was also determined and at 6 hr exposure time, the highest concentration (2 × MIC) exhibited bactericidal effect across all three Vibrio species. The result derived in this research, therefore, propose that combination therapy is a promising solution to antimicrobial resistance in Vibrio species. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Ayodele, Oluwakemi Victoria
- Date: 2021-04
- Subjects: Drug resistance in microorganisms , Vibrio cholerae
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20396 , vital:45661
- Description: Increased rate of antibiotic resistance (AR) poses a serious threat with a resultant notion of a possible end of the antibiotics era, making it a problem of concern to public health and a great implication on the world economy and human society. Despite many approaches developed to curb this menace, antibiotics resistance is still a challenge worldwide. This has made the use of combined therapy as one of the options in many cases. This study was conducted to assess antibiotics combination therapy as an option for the control of antimicrobial-resistant non-cholera causing Vibrio species that were recovered from the environment in the Eastern Cape, South Africa. Two hundred and twenty-eight Vibrio species were recovered from the environment in the Province, and these were deposited in the archive of AEMREG. PCR was used to identify target Vibrio species. Disc diffusion method was used to evaluate the antibiotic susceptibility profile of the confirmed isolates against 11 antibiotics commonly used against infections. MIC and MBC were determined using antibiotics (imipenem, tetracycline, and nalidixic acid) that high resistance was discovered. Checkerboard assay was used to carry out antibiotics combination assay, and the FICI was calculated. Rate of kill was also determined using ½ × MIC, 1 × MIC, and 2 × MIC concentrations of the combined antibiotics at 2 hr intervals. One hundred of the isolates were confirmed to be Vibrio parahaemolyticus, 82 were Vibrio vulnificus and 46 were Vibrio fluvialis. Twenty-two (22) percent of the Vibrio parahaemolyticus isolates showed resistance against tetracycline and their resistance against other antimicrobials is as follows; nalidixic acid (16 percent), ampicillin (14 percent), cefotaxime (14 percent), chloramphenicol (12 percent) and amikacin (11 percent). For Vibrio vulnificus, prevalence of resistance was as follows: imipenem (40 percent), tetracycline (22 percent), ampicillin (18 percent), meropenem (15 percent), and chloramphenicol (11 percent). Vibrio fluvialis showed the following resistance profile: nalidixic acid (28 percent), tetracycline (28percent), ampicillin (20 percent), chloramphenicol (15 percent), amikacin (11 percent) and cefotaxime (11 percent). About 38 multiple antibiotic resistance phenotypes (MARP) were recorded in all species that were evaluated. About 23 percent were resistant to over 3 antibiotics used. The multiple antibiotic resistant indices (MARI) ranged between 0.3 and 0.8. MIC and MBC were carried against isolates that were resistant to the two most common antibiotics tested. MIC and MBC were determined in the following order: tetracycline and nalidixic acid at concentrations ranging from 16 μg/ml to 1024 μg/ml for Vibrio parahaemolyticus and 32 μg/ml to 2048 μg/ml for Vibrio fluvialis. Also, the MIC and MBC of imipenem and tetracycline at concentrations ranging from 8 μg/ml to 256 μg/ml for Vibrio vulnificus were determined. Antibiotics combination therapy was carried out and synergistic activity was observed in 3 of the 16 resistant V. parahaemolyticus isolates, 3 of the16 resistant V. vulnificus isolates and 2 of the 13 resistant V. fluvialis isolates. Antagonism was not observed across all the drug combinations. Rate of kill was also determined and at 6 hr exposure time, the highest concentration (2 × MIC) exhibited bactericidal effect across all three Vibrio species. The result derived in this research, therefore, propose that combination therapy is a promising solution to antimicrobial resistance in Vibrio species. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-04
Barriers and reasons for exercise of rural and urban overweight and obese populations in Buffalo City Metropolitan Municipality, Eastern Cape
- Authors: Mrwebi, Thembani
- Date: 2021-04
- Subjects: Obesity--Prevention , Public health--Exercise
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22522 , vital:52388
- Description: It is documented that obesity is highly prevalent across rural and urban groups in industrialised and underdeveloped countries. This problem is an alarming issue as community members remain unsure about avoiding risking their health. Various health surveys reveal that obesity has increased among communities in the Buffalo City Metro Municipality in the Eastern Cape, and it has consequently made communities vulnerable to non-communicable diseases. The researcher explored factors and barriers of exercise for rural and urban obese populations in Buffalo City Metropolitan Municipality, Eastern Cape. This study was descriptive and explorative, utilising a questionnaire for gathering information. A purposive sample of 80 members from the two selected communities completed the questionnaire. A factor analysis was performed to identify factors that motivate physical activity and barriers to physical activity. It was discovered that all evaluated members were fully aware of the harmful repercussions of being overweight or obese. Nevertheless, only a tiny percentage of those who took part in the study decided to live a healthier lifestyle because of their obesity. Constructive motivating factors included increasing their self-image, enhancing their wellbeing, and getting highly involved in active and regular exercise. Negative motivators included finding it challenging to fit into old clothes and the worry of developing obesity-related diseases. Respondents noted the following impediments in regular exercises and physical activities; African cultural values, limited operational hours of physical activity facilities, insufficient time, and a lack of enthusiasm. , Thesis (MPhil) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Mrwebi, Thembani
- Date: 2021-04
- Subjects: Obesity--Prevention , Public health--Exercise
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22522 , vital:52388
- Description: It is documented that obesity is highly prevalent across rural and urban groups in industrialised and underdeveloped countries. This problem is an alarming issue as community members remain unsure about avoiding risking their health. Various health surveys reveal that obesity has increased among communities in the Buffalo City Metro Municipality in the Eastern Cape, and it has consequently made communities vulnerable to non-communicable diseases. The researcher explored factors and barriers of exercise for rural and urban obese populations in Buffalo City Metropolitan Municipality, Eastern Cape. This study was descriptive and explorative, utilising a questionnaire for gathering information. A purposive sample of 80 members from the two selected communities completed the questionnaire. A factor analysis was performed to identify factors that motivate physical activity and barriers to physical activity. It was discovered that all evaluated members were fully aware of the harmful repercussions of being overweight or obese. Nevertheless, only a tiny percentage of those who took part in the study decided to live a healthier lifestyle because of their obesity. Constructive motivating factors included increasing their self-image, enhancing their wellbeing, and getting highly involved in active and regular exercise. Negative motivators included finding it challenging to fit into old clothes and the worry of developing obesity-related diseases. Respondents noted the following impediments in regular exercises and physical activities; African cultural values, limited operational hours of physical activity facilities, insufficient time, and a lack of enthusiasm. , Thesis (MPhil) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-04
Effect of fire frequency on the recovery of soil invertebrate communities in semi-arid savanna biome of the Eastern Cape, South Africa
- Madikana, Ayabulela https://orcid.org/0000-0002-9119-4650
- Authors: Madikana, Ayabulela https://orcid.org/0000-0002-9119-4650
- Date: 2021-04
- Subjects: Soil invertebrates , Fire ecology , Arid regions
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22831 , vital:52946
- Description: Fires are common in South African savanna habitats, which can disrupt the dynamics of entire invertebrate populations, endangering biodiversity and the environment. The aim of this study was to look at how fire frequency affected invertebrate population dynamics and biodiversity in a 41-year-old fire experiment at the University of Fort Hare research farm in Alice. The experiment had six different levels of burning frequency: no-burn (K), annual burn (B1), biannual burn (B2), triennial burn (B3), quadrennial burn (B4), and sexennial burn (B6). The experimental plots were replicated two times in a randomized complete block design and have been continuously retained since 1980. A ground yellow mustard solution was used to collect earthworms, which were then identified by an earthworm taxonomist. Pitfall traps were used to collect ants and other insects, which were then identified under a microscope. In total, three soil samples were collected from each plot to assess selected soil nutrients, moisture, and pH. The Shannon diversity index, richness, and population of earthworms, ants, and other insects were calculated, and a one-way ANOVA analysis was done to check if the treatments differed significantly. A correlations study was used to look for any influence connected to soil parameters, including the Shannon diversity index, species richness, and density of soil invertebrates. According to our findings, the measured parameters did not show any significant differences in the measured parameters between the different frequency levels. All the plots had two species of earthworm , Proandricus timmianus and Proandricus beddardi except the biennial burn plot, which had all three, the afore mentioned species and one other unidentified species, Proandricus sp. The triennial burn treatment slightly enhanced the insect diversity, richness, and evenness of ant species difference while the diversity, evenness, and richness were lowest in the sexennial burn plot. However, there was no signif difference in population. After B4, the no burn plot had the second largest diversity and species richness, and the third highest species evenness and had a 100 percent species similarity index. The ants were evenly distributed in the no burn plot compared to the other plots, with K having a lower density than the other plots except for B4, K being slightly more diverse than B6, and B1 with a slightly lower diversity than the other plots, and it being the third species rich plot after B2 and B3, followed by the rest of the plots. This study implied that fire frequency has an insignificant impact on invertebrates’ communities in Savanna biomes words.icant , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Madikana, Ayabulela https://orcid.org/0000-0002-9119-4650
- Date: 2021-04
- Subjects: Soil invertebrates , Fire ecology , Arid regions
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22831 , vital:52946
- Description: Fires are common in South African savanna habitats, which can disrupt the dynamics of entire invertebrate populations, endangering biodiversity and the environment. The aim of this study was to look at how fire frequency affected invertebrate population dynamics and biodiversity in a 41-year-old fire experiment at the University of Fort Hare research farm in Alice. The experiment had six different levels of burning frequency: no-burn (K), annual burn (B1), biannual burn (B2), triennial burn (B3), quadrennial burn (B4), and sexennial burn (B6). The experimental plots were replicated two times in a randomized complete block design and have been continuously retained since 1980. A ground yellow mustard solution was used to collect earthworms, which were then identified by an earthworm taxonomist. Pitfall traps were used to collect ants and other insects, which were then identified under a microscope. In total, three soil samples were collected from each plot to assess selected soil nutrients, moisture, and pH. The Shannon diversity index, richness, and population of earthworms, ants, and other insects were calculated, and a one-way ANOVA analysis was done to check if the treatments differed significantly. A correlations study was used to look for any influence connected to soil parameters, including the Shannon diversity index, species richness, and density of soil invertebrates. According to our findings, the measured parameters did not show any significant differences in the measured parameters between the different frequency levels. All the plots had two species of earthworm , Proandricus timmianus and Proandricus beddardi except the biennial burn plot, which had all three, the afore mentioned species and one other unidentified species, Proandricus sp. The triennial burn treatment slightly enhanced the insect diversity, richness, and evenness of ant species difference while the diversity, evenness, and richness were lowest in the sexennial burn plot. However, there was no signif difference in population. After B4, the no burn plot had the second largest diversity and species richness, and the third highest species evenness and had a 100 percent species similarity index. The ants were evenly distributed in the no burn plot compared to the other plots, with K having a lower density than the other plots except for B4, K being slightly more diverse than B6, and B1 with a slightly lower diversity than the other plots, and it being the third species rich plot after B2 and B3, followed by the rest of the plots. This study implied that fire frequency has an insignificant impact on invertebrates’ communities in Savanna biomes words.icant , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-04
Evaluation of anti-diabetic activity of selected red marine macro-algae found along South African coastal areas
- Bambo, Karabo https://orcid.org/0000-0002-3721-2424
- Authors: Bambo, Karabo https://orcid.org/0000-0002-3721-2424
- Date: 2021-04
- Subjects: Marine algae , Phytochemicals
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22533 , vital:52405
- Description: Marine macro-algae are a good source of potential primary and secondary metabolites. Phytochemicals of the samples were extracted using methanol and water. This study evaluated the phytochemical constituents, antioxidant activity and antidiabetic activity of selected red marine macro-algae sampled from Gqeberha, South Africa. The species collected were identified as Gelidium pristoides, Scinaia furcellata and Portieria tripinita using DNA barcoding. Results showed the presence of several phytochemicals such as saponins, phenols, flavonols, tannins, proanthocyanidins and flavonoids. Methanol was a more effective polyphenol extraction solvent than water. Gelidium pristoides (H2O) was observed to contain the highest phenol and proanthocyanidin content, which correlated to Gelidium pristoides (H2O) having the greatest FRAP and DPPH radical scavenging activity IC50 at 0.227. Portieria tripinita (MeOH) extract had the greatest flavonoid content. Flavonol content was high for Scinaia furcellata while the highest tannin content was observed in both H2O and MeOH extracts of Gelidium pristoides. All the selected marine macro-algae species showed concentration-dependent reducing power. The extract with the highest ABTS scavenging activity was Gelidium pristoides (MeOH) IC50 at 0.227. Portieria tripinita was the only species that showed Nitric oxide scavenging activity, with (H2O) extract showing the highest activity IC50 at 3.052. Only MeOH extracts of Gelidium pristoides and Scinaia furcellata showed very slight α-amylase inhibition, however, all extracts successfully inhibited the activity of α-glucosidase with the exception of the H2O extracts of Scinaia furcellata. All crude extracts of Gelidium pristoides, Scinaia furcellata and Portieria tripinita showed no significant/weak effect on glucose uptake and utilization by C3A cells following 24 hours of treatment, with the exception of the aqueous extracts of Scinaia furcellata at the highest concentration of 100 μg/ml. The in-vitro MTT cytotoxicity assay revealed that only MeOH extracts of Gelidium pristoides and Scinaia furcellata had a 15 significant toxic effect on C3A hepatocytes at concentrations of 100 μg/ml and 25μg/ml, respectively. Portieria tripinita aqueous extract showed cytotoxicity when evaluated using Hoechst 33342/Propidium iodide (PI) dual staining. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Bambo, Karabo https://orcid.org/0000-0002-3721-2424
- Date: 2021-04
- Subjects: Marine algae , Phytochemicals
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22533 , vital:52405
- Description: Marine macro-algae are a good source of potential primary and secondary metabolites. Phytochemicals of the samples were extracted using methanol and water. This study evaluated the phytochemical constituents, antioxidant activity and antidiabetic activity of selected red marine macro-algae sampled from Gqeberha, South Africa. The species collected were identified as Gelidium pristoides, Scinaia furcellata and Portieria tripinita using DNA barcoding. Results showed the presence of several phytochemicals such as saponins, phenols, flavonols, tannins, proanthocyanidins and flavonoids. Methanol was a more effective polyphenol extraction solvent than water. Gelidium pristoides (H2O) was observed to contain the highest phenol and proanthocyanidin content, which correlated to Gelidium pristoides (H2O) having the greatest FRAP and DPPH radical scavenging activity IC50 at 0.227. Portieria tripinita (MeOH) extract had the greatest flavonoid content. Flavonol content was high for Scinaia furcellata while the highest tannin content was observed in both H2O and MeOH extracts of Gelidium pristoides. All the selected marine macro-algae species showed concentration-dependent reducing power. The extract with the highest ABTS scavenging activity was Gelidium pristoides (MeOH) IC50 at 0.227. Portieria tripinita was the only species that showed Nitric oxide scavenging activity, with (H2O) extract showing the highest activity IC50 at 3.052. Only MeOH extracts of Gelidium pristoides and Scinaia furcellata showed very slight α-amylase inhibition, however, all extracts successfully inhibited the activity of α-glucosidase with the exception of the H2O extracts of Scinaia furcellata. All crude extracts of Gelidium pristoides, Scinaia furcellata and Portieria tripinita showed no significant/weak effect on glucose uptake and utilization by C3A cells following 24 hours of treatment, with the exception of the aqueous extracts of Scinaia furcellata at the highest concentration of 100 μg/ml. The in-vitro MTT cytotoxicity assay revealed that only MeOH extracts of Gelidium pristoides and Scinaia furcellata had a 15 significant toxic effect on C3A hepatocytes at concentrations of 100 μg/ml and 25μg/ml, respectively. Portieria tripinita aqueous extract showed cytotoxicity when evaluated using Hoechst 33342/Propidium iodide (PI) dual staining. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-04
Smallholder farmers’ perception in the adoption of in-field rainwater harvesting techniques in Raymond Mhlaba Local Municipality, Eastern Cape, South Africa
- Mtyelwa, Chuma https://orcid.org/0000-0002-0696-4340
- Authors: Mtyelwa, Chuma https://orcid.org/0000-0002-0696-4340
- Date: 2021-04
- Subjects: Farms, Small , Water harvesting
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/21367 , vital:48499
- Description: Dissemination, adoption and continued use of adopted technologies are key requirements for improved smallholder farmers’ productivity. In an attempt to improve smallholder agricultural production and creating a resilient smallholder agricultural sector, many technologies such as the in-field rainwater harvesting technique (IRWHT) have been put in place. IRWHT has a tremendous potential for improving livelihoods of rural smallholder farmers, thus decreasing their vulnerability to vagaries of climate change. However, though IRWHT was promoted for agricultural crop production improvement, smallholder farmers discontinued its adoption. This study critically assessed the perception of smallholder farmers in Raymond Mhlaba Local Municipality (RMLM) on the use of the in-field rainwater harvesting technique to assess the underlying factors that led to IRWHT dis-adoption. This study adopted a descriptive study design; purposive sampling was used to select a sample of 120 smallholder farmers that initially adopted IRWHT. Data was gathered through a face-to-face interview and with a pre-tested semi-structured questionnaire. Descriptive statistical analysis frequency count, percentages, means and standard deviation were used for quantitative data analysis. The findings revealed that 96percent of smallholder farmers dis-adopted IRWHT after initial adoption. Moreover, IRWHT was dis-adopted 5-8 years post adoption. Critical reasons behind discontinuity include small land size (23percent), lack of reliable water source (18percent), complexity of IRWHT, continual extension support (17percent) and IRWHT taking up much space (13percent), amongst others. This study also revealed that farmers’ perception towards the innovation attributes of IRWHT, in relative advantage over economic returns such as profitability, had an impact on dis-adoption of IRWHT, with a negative farmers’ perception (𝑥̅ = 2.95). Complexity of IRWHT was associated with discontinuity of IRWHT by smallholder farmers in RMLM, with the majority (60percent) of smallholder farmers indicating that IRWHT was labour intensive. Some (39.9percent) stated that implementation of IRWHT was time consuming. Innovation attributes that led to a high rate of initial adoption were relative advantage with better yield (𝑥̅ = 4. 38) and compatibility. Smallholder farmers indicated that IRWHT can be implemented with cheaper and available working tools (𝑥̅ = 3.54). On trialability, smallholder farmers indicated that IRWHT was triable in different seasons and on observability smallholder farmers had a positive perception (𝑥̅ = 3.81) towards observable improved crop yield. Smallholder farmers had a positive perception (𝑥̅ = 4.14) of extension service support during the scaling-up of IRWHT although they indicated that the extension service support had ceased. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Mtyelwa, Chuma https://orcid.org/0000-0002-0696-4340
- Date: 2021-04
- Subjects: Farms, Small , Water harvesting
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/21367 , vital:48499
- Description: Dissemination, adoption and continued use of adopted technologies are key requirements for improved smallholder farmers’ productivity. In an attempt to improve smallholder agricultural production and creating a resilient smallholder agricultural sector, many technologies such as the in-field rainwater harvesting technique (IRWHT) have been put in place. IRWHT has a tremendous potential for improving livelihoods of rural smallholder farmers, thus decreasing their vulnerability to vagaries of climate change. However, though IRWHT was promoted for agricultural crop production improvement, smallholder farmers discontinued its adoption. This study critically assessed the perception of smallholder farmers in Raymond Mhlaba Local Municipality (RMLM) on the use of the in-field rainwater harvesting technique to assess the underlying factors that led to IRWHT dis-adoption. This study adopted a descriptive study design; purposive sampling was used to select a sample of 120 smallholder farmers that initially adopted IRWHT. Data was gathered through a face-to-face interview and with a pre-tested semi-structured questionnaire. Descriptive statistical analysis frequency count, percentages, means and standard deviation were used for quantitative data analysis. The findings revealed that 96percent of smallholder farmers dis-adopted IRWHT after initial adoption. Moreover, IRWHT was dis-adopted 5-8 years post adoption. Critical reasons behind discontinuity include small land size (23percent), lack of reliable water source (18percent), complexity of IRWHT, continual extension support (17percent) and IRWHT taking up much space (13percent), amongst others. This study also revealed that farmers’ perception towards the innovation attributes of IRWHT, in relative advantage over economic returns such as profitability, had an impact on dis-adoption of IRWHT, with a negative farmers’ perception (𝑥̅ = 2.95). Complexity of IRWHT was associated with discontinuity of IRWHT by smallholder farmers in RMLM, with the majority (60percent) of smallholder farmers indicating that IRWHT was labour intensive. Some (39.9percent) stated that implementation of IRWHT was time consuming. Innovation attributes that led to a high rate of initial adoption were relative advantage with better yield (𝑥̅ = 4. 38) and compatibility. Smallholder farmers indicated that IRWHT can be implemented with cheaper and available working tools (𝑥̅ = 3.54). On trialability, smallholder farmers indicated that IRWHT was triable in different seasons and on observability smallholder farmers had a positive perception (𝑥̅ = 3.81) towards observable improved crop yield. Smallholder farmers had a positive perception (𝑥̅ = 4.14) of extension service support during the scaling-up of IRWHT although they indicated that the extension service support had ceased. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-04
Understanding the contribution of Land Use/Cover (LUC) classes on soil erosion and sedimentation using sediment fingerprinting technique and RUSLE in a GIS interface at sub-catchment level
- Taeni, Thembalethu (https://orcid.org/ 0000-0001-7662-8652)
- Authors: Taeni, Thembalethu (https://orcid.org/ 0000-0001-7662-8652)
- Date: 2021-04
- Subjects: Geographic information systems , Soil erosion , River sediments
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20920 , vital:46747
- Description: Soil erosion by water is the major source of soil degradation in the world, and South Africa (SA) is not an exception particularly in the Free State (FS) Province. In South Africa, the Caledon River Catchment in the FS Province has been identified as one of the regions where soil erosion has been prevalent for decades. Evidence across many parts of the catchment show a widespread of soil erosion and the contaminant flux associated with sediment into river systems and reservoirs; including the Welbedatcht dam and Carthcart-drift dam in Ladybrand. It is of these issues that the current work aimed at enhancing the understanding of sediment sources and soil erosion dynamics at the Caledon River Basin. The objectives of the study were to locate sources of suspended sediments and to assess and quantify the contribution of Land Use Cover (LUC) classes to water erosion and sediment yield at a sub – catchment level of the Caledon River Basin. To achieve the objectives set out for this research, a study was conducted at a sub - catchment level of the Caledon River Basin in the FS Province, South Africa. The sediment–fingerprinting approach and the Revised Universal Soil Loss Equation (RUSLE) model were used in the study under Geographic Information System (GIS) settings. A qualitative and quantitative interpretation of the geochemical data were used to evaluate the potential for distinguishing catchment sediment sources. The application of multivariate sediment mixing models incorporating Monte Carlo simulations was undertaken to investigate recent variations in sediment sources. Lastly, to document the impact of LUC change on soil erosion; data from soil profile database, Landsat 8 OLI–TIRS and climate (i.e. rainfall) were used to assess and map the spatial and temporal pattern changes of soil erosion at a sub – catchment level as related to LUC changes. In this study, the sub–catchment was classified into 6 LUC classes. Thereafter soil erosion was quantified for three consecutive years namely; 2015, 2016 and 2018 using the soil erosion factors as GIS–layers. The investigation of sediment source types and spatial provenance in the catchment showed that the grassland areas have consistently been the main sediment source (83 percent) throughout the study period. Findings further showed that there was an increase in contributions from cultivation and abandoned cultivated fields. Sediment contribution from surface sources was dominant (54 percent) and thereafter, subsurface sediment input increased (62 percent). This trend is indicative of increased severity of gully erosion in the area and thus is consistent with other studies. To comprehend the influence of LUC class modification dynamics on soil erosion, water erosion in particular at the sub-catchment commencing from 2015 to 2018 (4 years), multi-temporal Landsat 8 information jointly with the RUSLE model were used. A post-classification, LUC class alteration comparison revealed that water bodies, shrubs and forested region and grassland declined by 0.27 percent, 15.60 percent, and 37.60 percent, respectively. On the other hand, regions under Bad lands, and bare-soil and built-up regions including agricultural region expanded by 2.22 percent, 5.78 percent, and 45.67 percent respectively, between 2015 to 2018 study period. The average yearly soil loss decreased at the sub-catchment and was 10.23,5.71 and 5.82 t ⋅ ha -1 ⋅ yr-1 for 2015, 2016 and 2018 respectively. Although soil loss lessened for the duration of the perceived period, a closer scrutiny revealed that there were nonetheless seeming signs of persistent escalation in soil loss risk. These signs were mostly shown in the elevated parts of the sub-catchment as shown by the red regions on the soil loss map. Additional examination of soil loss findings by LUC classes categories further indicated that most LUC classes categories, including Bare-soil and built-up area, agricultural-land, grassland, and region under shrubs and forests, showed increased soil loss levels during the 4 years’ study period at the sub-catchment. The information on the comparative vividness of diverse sediment sources given by the study must be observed as a noteworthy development towards an understanding of the sediment source dynamics in agricultural river based catchments; more so of the Caledon River Basin. Further research is recommended for other erosion prone catchments in South Africa to identify additional evidence of the spatial and temporal variations in soil erosion and sediment sources. The results of the study suggest that the procedure of assimilating the GIS and RS with the RUSLE model is not just precise, time-efficient and exact in recognizing soil erosion susceptible regions in geospatial and temporal standings. However, it is a cost-efficient substitute to standard field-founded approaches. , Thesis (MSc) (Soil Science) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Taeni, Thembalethu (https://orcid.org/ 0000-0001-7662-8652)
- Date: 2021-04
- Subjects: Geographic information systems , Soil erosion , River sediments
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20920 , vital:46747
- Description: Soil erosion by water is the major source of soil degradation in the world, and South Africa (SA) is not an exception particularly in the Free State (FS) Province. In South Africa, the Caledon River Catchment in the FS Province has been identified as one of the regions where soil erosion has been prevalent for decades. Evidence across many parts of the catchment show a widespread of soil erosion and the contaminant flux associated with sediment into river systems and reservoirs; including the Welbedatcht dam and Carthcart-drift dam in Ladybrand. It is of these issues that the current work aimed at enhancing the understanding of sediment sources and soil erosion dynamics at the Caledon River Basin. The objectives of the study were to locate sources of suspended sediments and to assess and quantify the contribution of Land Use Cover (LUC) classes to water erosion and sediment yield at a sub – catchment level of the Caledon River Basin. To achieve the objectives set out for this research, a study was conducted at a sub - catchment level of the Caledon River Basin in the FS Province, South Africa. The sediment–fingerprinting approach and the Revised Universal Soil Loss Equation (RUSLE) model were used in the study under Geographic Information System (GIS) settings. A qualitative and quantitative interpretation of the geochemical data were used to evaluate the potential for distinguishing catchment sediment sources. The application of multivariate sediment mixing models incorporating Monte Carlo simulations was undertaken to investigate recent variations in sediment sources. Lastly, to document the impact of LUC change on soil erosion; data from soil profile database, Landsat 8 OLI–TIRS and climate (i.e. rainfall) were used to assess and map the spatial and temporal pattern changes of soil erosion at a sub – catchment level as related to LUC changes. In this study, the sub–catchment was classified into 6 LUC classes. Thereafter soil erosion was quantified for three consecutive years namely; 2015, 2016 and 2018 using the soil erosion factors as GIS–layers. The investigation of sediment source types and spatial provenance in the catchment showed that the grassland areas have consistently been the main sediment source (83 percent) throughout the study period. Findings further showed that there was an increase in contributions from cultivation and abandoned cultivated fields. Sediment contribution from surface sources was dominant (54 percent) and thereafter, subsurface sediment input increased (62 percent). This trend is indicative of increased severity of gully erosion in the area and thus is consistent with other studies. To comprehend the influence of LUC class modification dynamics on soil erosion, water erosion in particular at the sub-catchment commencing from 2015 to 2018 (4 years), multi-temporal Landsat 8 information jointly with the RUSLE model were used. A post-classification, LUC class alteration comparison revealed that water bodies, shrubs and forested region and grassland declined by 0.27 percent, 15.60 percent, and 37.60 percent, respectively. On the other hand, regions under Bad lands, and bare-soil and built-up regions including agricultural region expanded by 2.22 percent, 5.78 percent, and 45.67 percent respectively, between 2015 to 2018 study period. The average yearly soil loss decreased at the sub-catchment and was 10.23,5.71 and 5.82 t ⋅ ha -1 ⋅ yr-1 for 2015, 2016 and 2018 respectively. Although soil loss lessened for the duration of the perceived period, a closer scrutiny revealed that there were nonetheless seeming signs of persistent escalation in soil loss risk. These signs were mostly shown in the elevated parts of the sub-catchment as shown by the red regions on the soil loss map. Additional examination of soil loss findings by LUC classes categories further indicated that most LUC classes categories, including Bare-soil and built-up area, agricultural-land, grassland, and region under shrubs and forests, showed increased soil loss levels during the 4 years’ study period at the sub-catchment. The information on the comparative vividness of diverse sediment sources given by the study must be observed as a noteworthy development towards an understanding of the sediment source dynamics in agricultural river based catchments; more so of the Caledon River Basin. Further research is recommended for other erosion prone catchments in South Africa to identify additional evidence of the spatial and temporal variations in soil erosion and sediment sources. The results of the study suggest that the procedure of assimilating the GIS and RS with the RUSLE model is not just precise, time-efficient and exact in recognizing soil erosion susceptible regions in geospatial and temporal standings. However, it is a cost-efficient substitute to standard field-founded approaches. , Thesis (MSc) (Soil Science) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-04
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