Browsing by Author "Maina, Samuel"

Now showing 1 - 10 of 10
  • No Thumbnail Available
    Item
    Does Inquiry-Based Learning Approach In Chemistry Practical Lessons Affect Students’ Nzomo Attitudes And Self-Efficacy In Chemistry? A Case Of Meru South Sub-County,Kenya
    (UoEm, 2023-05) Maina, Samuel
    xiv ABSTRACT Chemistry is a crucial subject for a country like Kenya that seeks to be industrialized by the year 2030. Even though the subject is important, performance in the subject has been declining consistently in Kenya. A decline in performance in Chemistry has also been reported in Meru South Sub-County. The decline in performance has been attributed to teacher-centered learning methodologies, negative attitudes of students towards the subject and low self-efficacy. Teachers have been encouraged to use Inquiry-Based Learning (IBL) approach in teaching of Chemistry and particularly in practical lessons because it has been associated with improved attitudes and self-efficacy. However, little is known on the uptake of inquiry-based learning approach by teachers in Chemistry practical lessons and how it is related to students’ attitudes and self-efficacy in Chemistry in Meru South Sub-County secondary schools. The purpose of this research was to examine the utilization of inquiry-based learning approach in Chemistry practical lessons, and determine the relationship between the utilization of inquiry-based learning approach and selected performance predictors i.e. students’ attitudes and self-efficacy in Chemistry. The study was guided by the Vygotsky’s social constructivism theory which emphasizes on the role of social interactions and active construction of knowledge. A mixed method research design was employed in this study. The target population was all secondary schools in Meru South Sub-County. Stratified and purposive sampling was used to select both public and private secondary schools. Purposive sampling was used to select 42 form three Chemistry teachers while 357 students were chosen for the research using basic random selection. Data collection was done using practical lesson observation schedule, teacher’s questionnaire, student’s questionnaire, and document analysis framework. Results revealed that teachers used inquiry-based learning approach in Chemistry practical lessons once a week (mean = 3.89). Results from correlation and regression analysis revealed that there is a significant positive relationship between inquiry-based learning and students’ attitudes towards Chemistry (r = .9972, p = .000, t = 58.285, p = 0.00). Besides, it was established that inquiry-based learning is positively associated with students’ efficacy beliefs in Chemistry (β= 0.903, p < 0.05). From the study findings, it was concluded that inquiry-based learning approach is an effective teaching technique for enhancing positive attitudes towards Chemistry among students as well as improving their confidence in Chemistry. The study findings are significant in the education sector in improving teacher training programs and calls for shift from teacher-centered teaching methodologies to learner centered teaching methodologies among practicing teachers.
  • Thumbnail Image
    Item
    Free-living nematode assemblages associated with maize residues and their ecological significance
    (2021) Karuri, Hannah W.; Maina, Samuel; Nyoike, Rossa N.
    Return of plant residues to the soil is a sustainable way of enhancing plant growth, health, and levels of soil quality. In Kenya, maize plant residues are the most commonly returned plant material in many agro-ecosystems. For any plant material to release nutrients into the soil, it must undergo a decomposition process that is usually affected by various organisms, especially nematodes. Despite their great contribution to the breakdown of plant organic matter, there is a dearth of information on the interaction between maize residues and free-living nematodes (FLN) in Kenya. In this respect, this study aimed to assess the influence of decomposing maize residues on FLN dynamics and the soil food web in Mwea, Kenya. The experimental plots were set up in a randomized complete block design, comprising of decomposition plots (incorporated with maize residue to a depth of 30 cm at a rate of 5 tons/hectare), while the plots unincorporated with maize residues were used as the control. Each treatment consisted of four replicates. In all, 30 FLN genera were recovered from the field trials, whereby Acrobeles was significantly abundant in decomposition plots in both seasons. We subsequently found that maize residues reduced the abundance of enrichment opportunist bacterivores (cp-1) relative to general opportunist (cp-2) bacterivores and fungivores. Notably, the results of the channel index showed that the decomposition of maize residues was dominated by fungal energy channels throughout the study in the two seasons. These results suggest that maize residues need to be coupled with a suitable labile organic matter. This would lead to sustainable, active, and reliable turn-over of maize residues into the soil food web ecosystems. The application of labile materials can also help to improve the population of enrichment bacterivores that are essential in the decomposition process. This study shows that the decomposition of maize residues influenced FLN composition, mainly the enrichment opportunist bacterivores whose abundance was lower.
  • No Thumbnail Available
    Item
    Functional Diversity and Ecological Role Of Nematodes in Pigeon Pea And Maize-Pigeon Pea Agro-Ecosystems
    (UoEm, 2023-08) Maina, Samuel
    Kenya relies heavily on pigeon pea (Cajanus cajan L.) and maize (Zea mays L.) as essential food crops, widely grown by small-holder farmers for food, feed, and income. These crops face significant production challenges due to plant-parasitic nematodes (PPN), which cause enormous yield losses. The four main species of PPN that negatively impact pigeon pea and maize are Meloidogyne spp., Rotylenchulus spp., Heterodera spp., and Pratylenchus spp. Plant-parasitic nematodes cause 50% and 8-35% yield reductions in maize and pigeon pea, respectively. Besides the presence of PPN, Kenyan agro-ecosystems have a high density of free-living nematodes (FLN) that perform vital functions, including breaking down organic matter, cycling nutrients, pest regulation and serving as bio-indicators of ecosystem quality. The objective of this study was to assess the variety of nematodes present in monocrop pigeon peas (PP) as well as the nematode community structure and their role as soil health indicators in maize-pigeon pea (MPP) agro-ecosystems. The study also determined the nematode functional guild diversity and their ecological role in PP and MPP agro-ecosystems, and the distribution and prevalence of PPN feeding groups in PP and MPP agro-ecosystems. For all objectives, baseline field surveys were carried out in respective PP and MPP farmers’ fields in Embu County using probability frame sampling design coupled with three separate W shaped “sample walk” pattern. For PP across the eight regions in Mbeere North, Embu County, 46 nematode genera were identified, of which Meloidogyne, Rotylenchulus, Acrobeloides and Cervidellus differed significantly among the regions. No variations were observed in Simpson diversity, Shannon, Pielou's evenness, and genus richness measures between regions at P > 0.05. Canonical correspondence analysis (CCA) showed marked connections between soil characteristics and specific nematode genera, with the first two axes explaining 56.65% of the total variation. For MPP agro-ecosystems across eight regions in Mbeere South, Embu County, 41 nematode genera were identified with Longidorus spp., Heterocephalobus spp. and Mononchus spp. varying significantly among the regions. Following structure and enrichment indices analysis, Irabari soil food web was degraded, while the other seven regions were well-structured. In all the studied regions, the energy pathways for decomposing organic matter were predominated by fungivores. Among the assessed nematode metabolic footprints, only bacterivore footprint showed marked variations. Regarding PP and MPP cropping systems in Mbeere South and Mbeere North sub-Counties, Embu County, nematode assemblages consisted of 45 and 44 genera in PP and MPP, respectively, of which Pratylenchus, Rotylenchulus, and Aphelenchoides varied markedly between the two cropping systems. Non-metric multidimensional scaling analysis indicated a deep overlap of nematode genera in the two systems at the community level. The MPP fields favored herbivores population assigned to PP2 and PP3 over the PP fields. Pearson correlation coefficients and CCA indicated sand, clay, Cu and pH as the most relevant soil properties for accounting the pattern of nematode community assemblages. In addition, the migratory endoparasites and epidermal/root hair feeders were significantly higher in MPP than in PP, while sedentary parasites and ectoparasites were more in PP than in MPP system. These results reveal a significant presence of economically important PPN in PP and MPP systems, which highlights the need for effective nematode management programs. The study also provides beneficial understanding of the structure and functioning of the nematode soil food web in PP and MPP, potentially contributing to the improvement of their yields and soil health.
  • No Thumbnail Available
    Item
    Nematode assemblages, food web indices and metabolic footprints in maize-pigeon pea agro-ecosystems
    (Elsevier Ltd, 2022-08-02) Maina, Samuel; Karuri, Hannah; Mugweru, Julius
    Pigeon pea (Cajanus cajan L.) and maize (Zea mays L.) are important food crops in developing countries due to their multiple benefits. However, their production is constrained by plant-parasitic nematodes (PPN) which cause significant yield losses. Understanding the nematode-based soil food web structure in maize-pigeon pea agroecosystems will allow sustainable PPN management by improving soil health. This study explored nematode community assemblages, indices and metabolic footprints in maize-pigeon pea agroecosystems in Mbeere South, Embu County, Kenya. Soil samples were collected from Gachuriri, Irabari, Kanduu, Kangeta, Kangungi, Kaninwathiga, Karimari and Mutugu regions. The recovered nematodes were identified to the genus level. There were 41 nematode genera across the eight regions. Longidorus spp., Heterocephalobus spp., Cervidellus spp., Mesorhabditis spp. and Mononchus spp. differed significantly across the regions. Meloidogyne spp., Scutellonema spp., Rotylenchulus spp. and Pratylenchus spp. were the most prevalent genera although their abundance was not statistically different across the regions. Using the structure and enrichment indices, soil food web in Irabari was degraded, whereas the other seven regions were structured. The main energy channel of organic matter decomposition in the studied regions was dominated by fungivores. There were no differences in metabolic footprints expect for bacterivore footprint. The occurrence of Hoplolaimus spp. and Xiphinema spp. showed a negative correlation with N, C, Mg and Na. This work provides useful insights into the maize-pigeon pea nematode soil food web structure and function which can be used in improving their yields and soil health
  • No Thumbnail Available
    Item
    Nematode assemblages, food web indices and metabolic footprints in maize-pigeon pea agro-ecosystems.
    (Elsevier, 2022-08) Maina, Samuel; Karuri, Hannah W.; Mugweru, Julius
    Pigeon pea (Cajanus cajan L.) and maize (Zea mays L.) are important food crops in developing countries due to their multiple benefits. However, their production is constrained by plant-parasitic nematodes (PPN) which cause significant yield losses. Understanding the nematode-based soil food web structure in maize-pigeon pea agroecosystems will allow sustainable PPN management by improving soil health. This study explored nematode community assemblages, indices and metabolic footprints in maize-pigeon pea agroecosystems in Mbeere South, Embu County, Kenya. Soil samples were collected from Gachuriri, Irabari, Kanduu, Kangeta, Kangungi, Kaninwathiga, Karimari and Mutugu regions. The recovered nematodes were identified to the genus level. There were 41 nematode genera across the eight regions. Longidorus spp., Heterocephalobus spp., Cervidellus spp., Mesorhabditis spp. and Mononchus spp. differed significantly across the regions. Meloidogyne spp., Scutellonema spp., Rotylenchulus spp. and Pratylenchus spp. were the most prevalent genera although their abundance was not statistically different across the regions. Using the structure and enrichment indices, soil food web in Irabari was degraded, whereas the other seven regions were structured. The main energy channel of organic matter decomposition in the studied regions was dominated by fungivores. There were no differences in metabolic footprints expect for bacterivore footprint. The occurrence of Hoplolaimus spp. and Xiphinema spp. showed a negative correlation with N, C, Mg and Na. This work provides useful insights into the maize-pigeon pea nematode soil food web structure and function which can be used in improving their yields and soil health.
  • No Thumbnail Available
    Item
    Nematode diversity and its association with soil properties in monocrop pigeon pea
    (Elsevier Ltd, 202-07-03) Maina, Samuel; Karuri, Hannah; Mugweru, Julius
    Pigeon pea is a versatile pulse crop grown in semi-arid regions of Kenya; however, its production is affected by plant-parasitic nematodes. The current study was undertaken to investigate the diversity of nematodes and the influence of soil properties on their diversity in monocrop pigeon pea fields in Mbeere North, Embu County, Kenya. Soil samples were collected from Gatunguru B, Gwakaithi, Itururi, Kambungu, Kanyueri, Karigiri, Mbangua and Njarange regions. From each field, soil samples were collected from a depth of 25 cm using W- shaped sampling pattern. The nematodes were identified to the genus level using morphological features. In total, 46 nematode genera assigned to five trophic levels were identified across the eight regions. Abundance of Meloidogyne, Rotylenchulus, Longidorus, Acrobeloides, Cervidellus, Panagrolaimus, Prismatolaimus and Wilsonema varied markedly among the eight regions. Bacterivores belonging to colonizer-persister group 2 were the most prevalent group. There were no differences in Pielou’s evenness, genus richness, Shannon and Simpson diversity indices across the regions. Canonical correspondence analysis indicated significant correlations between certain nematode genera and soil attributes with the first two axes accounting for 56.65% of the variance. Acrobeloides correlated positively with Mg, C, Mn and N, and negatively with Fe. The occurrence of Hoplolaimus and Meso- rhabditis was associated negatively with soil pH, clay and Ca, and positively with sand. The present work reveals a high abundance of economically important PPN in monocrop pigeon pea which necessitates that appropriate nematode management programs are implemented.
  • No Thumbnail Available
    Item
    Nematode diversity and its association with soil properties in monocrop pigeon pea
    (Elsevier, 2022-08) Maina, Samuel; Karuri, Hannah W.; Mugweru, Julius
    Pigeon pea is a versatile pulse crop grown in semi-arid regions of Kenya; however, its production is affected by plant-parasitic nematodes. The current study was undertaken to investigate the diversity of nematodes and the influence of soil properties on their diversity in monocrop pigeon pea fields in Mbeere North, Embu County, Kenya. Soil samples were collected from Gatunguru B, Gwakaithi, Itururi, Kambungu, Kanyueri, Karigiri, Mbangua and Njarange regions. From each field, soil samples were collected from a depth of 25 cm using W- shaped sampling pattern. The nematodes were identified to the genus level using morphological features. In total, 46 nematode genera assigned to five trophic levels were identified across the eight regions. Abundance of Meloidogyne, Rotylenchulus, Longidorus, Acrobeloides, Cervidellus, Panagrolaimus, Prismatolaimus and Wilsonema varied markedly among the eight regions. Bacterivores belonging to colonizer-persister group 2 were the most prevalent group. There were no differences in Pielou’s evenness, genus richness, Shannon and Simpson diversity indices across the regions. Canonical correspondence analysis indicated significant correlations between certain nematode genera and soil attributes with the first two axes accounting for 56.65% of the variance. Acrobeloides correlated positively with Mg, C, Mn and N, and negatively with Fe. The occurrence of Hoplolaimus and Mesorhabditis was associated negatively with soil pH, clay and Ca, and positively with sand. The present work reveals a high abundance of economically important PPN in monocrop pigeon pea which necessitates that appropriate nematode management programs are implemented.
  • No Thumbnail Available
    Item
    Nutrient content of sorghum hybrid lines between Gadam and hard coat tannin sorghum cultivars
    (Wiley, 2022-06) Shinda, Cecilia A.; Nthakanio, Paul N.; Gitari, Josiah N.; Runo, Steven; Mukono, Simon; Maina, Samuel
    Sorghum is an important food crop in the world that exhibits a predominant role in fulfilling the nutritional requirements, particularly in low- income group populations of marginal areas in Kenya. It is a principal source of proteins, carbohydrates, fats, and crude fibers (CFs), which are important nutrients necessary for human development and health. Reduced tannin in sorghum grains is desirable since it affects the availability of nutrients. This study aimed at assessing the nutrient content in filial generation one (F1 ) developed between Gadam (sorghum), which is low in tannin and hard coat tannin (sorghum) cultivars. The nutrient content analyses were carried out from samples collected in a completely randomized design experiment. Crude protein (CP) and tannin content were analyzed using the modified Kjeldahl method and vanillin- HCl methanol method, respectively, whereas moisture, fat, CF, ash, and carbohydrate contents were determined using Association of Official Analytical Chemists methods. Data collected were subjected to analysis of variance using R statistical software. Among the F1 s, Kari/Mtama- 1 x Gadam recorded the highest CP value of 10.390%. This differed significantly from Gadam x Kari/Mtama- 1 which recorded CP content of 9.770%. Kari/Mtama- 1 x Gadam recorded the highest fat and moisture contents of 2.299% and 8.600%, respectively. The highest CF content of 3.433% was recorded in Gadam x Serena. Gadam x Kari/Mtama- 1 recorded the highest ash content of 1.619%, whereas the highest carbohydrate (84.503%) and tannin content (0.771 mg/g) means were recorded in Seredo x Gadam. Results demonstrated that the choice of maternal and paternal parent influence CP, CF, and carbohydrate contents. Among the F1 s, tannin content ranged from 0.106 to 0.771 mg/g compared to 0.953 to 1.763 mg/g recorded in Serena and Seredo (hard coat seeded cultivars). This is an indication that tannin can be downregulated through hybridization.
  • No Thumbnail Available
    Item
    Performance assessment of Crosses between Gadam and Hardcore Tannin sorghum in hybrid lines production
    (2022-06) Shinda, Cecilia A.; Gitari, Josiah N.; Nthakanio, Paul N.; Runo, Steven; Gichimu, Bernard M.; Maina, Samuel
    Gadam cultivar of sorghum has been characterized by low yields compared to the international yield levels of sorghum. In this research, Gadam was crossed with Serena, Seredo, and Kari/Mtama-1 in an attempt to increase yield through heterosis. The objective of this study was to determine the level of compatibility and heterosis in crosses between Gadam and the three sorghum lines in a reciprocal crossing. Gadam was crossed with the three lines and their reciprocals to make six treatments that were subjected to compatibility and heterosis tests. The F1 hybrid lines and their parental controls were sown in a randomized complete block design in three replicates. Compatibility and heterosis data variances were analyzed using R statistical software. The cross between Gadam x Serena, Serena x Gadam and the parent Gadam exhibited moderate mean plant height ranging from 99.5 cm to 120.5 cm. The cross Gadam x Serena recorded a desirable negative mid-parent heterosis of -19.89 and -16.16 for plant height and days to maturity respectively. All F1 hybrids recorded positive mid-parent heterosis for the panicle length, the number of reproductive tillers, a thousand seed weight, and the number of tillers per plant. The crosses Gadam x Seredo, Seredo x Gadam, Gadam x Serena and Kari/Mtama-1 x Gadam recorded significantly lower grain filling percentages compared to their parents. In conclusion, the F1 hybrids differed significantly from their reciprocal crosses especially in days of heading, flowering, and maturity indicating a significant maternal influence in these traits. Also, the mid-parent and better parent heterosis had a nonsignificant difference in quantitative traits assessed except for the plant height and grain filling percentage.
  • No Thumbnail Available
    Item
    Rosemary (Rosmarinus officinalis L.) growth rate, oil yield and oil quality under differing soil amendments
    (Heliyon, 2022) Mwithiga, Gikuru; Maina, Samuel; Gitari, Josiah N.; Muturi, Phyllis
    In this work, we examined the influence of different soil amendments namely cow manure alone (Cm), cow manure plus fertilizer (Cm þ F), fertilizer alone (F) and unamended check, control on rosemary growth rate, fat content, oil yield and oil quality. Plant height (PLH), number of primary branches per plant (NOPB) and survival rate were assessed at 0, 90, 180, 270 and 360 days after planting during the 2020–2021 growing season. Rosemary plant essential oil and fat content were extracted using steam distillation and Soxhlet methods, respectively, and determined for quality using the gas chromatography with mass spectrometry (GC-MS) method. Plants grown under Cm had a higher PLH and NOPB, whereas the F treatment largely affected the survival rate of rosemary plants than the control. A total of 26 constituents were identified from the obtained rosemary oil grown under different treatments by use of GC-MS analysis with Cm treatment containing the highest number of oil compounds. The main rosemary oil compounds in the present work were alpha-pinene (29.80%–34.34%), eucalyptol (27.15%–30.26%), verbenone (7.63%–8.14%) and geraniol (4.47%–5.22%). The oil yield from the steam distillation method ranged from 0.45% (v/w) to 0.59% (v/w) while the fat content as measured using the Soxhlet method ranged between 11.22% and 13.36% across various treatments. The essential oil yield and fat content from rosemary grown under Cm, Cm þ F, or F conditions were not significantly different. This study shows that Cm markedly influenced rosemary oil quality when compared to other soil amendments.