MST-Department of Agricultural Sciences and Technology

Permanent URI for this collection

https://repository.ku.ac.ke/handle/123456789/1592

Browse

Now showing 1 - 20 of 104

Geographical Information System-Based Land Suitability Assessment for Sunflower (Helianthus Annus) Production in Morogoro District, Tanzania
(Kenyatta University, 2024-01) Nungula, Zephaline Emmanuely
In Tanzania, the soil information available is inadequate and very specific in regions considered as highly potential areas and relies on a few collected scattered information over a big area which is not enough for agricultural land use planning locally. This study aimed to assess the appropriateness of land in Tungi Farm based in Morogoro District, Tanzania for sunflower production using a Geographic Information System (GIS). To determine appropriate areas for sunflower production, three criteria: soil properties (pH, organic carbon, total nitrogen, cation exchange capacity, available phosphorus, potassium, and soil texture), topography (slope and altitude), and climate (temperature and rainfall) were selected from the literature and employed in suitability analysis. The Analytic Hierarchy Process (AHP) method of the Multi-Criteria Evaluation was used to assign a weight to each criterion as per Saaty’s Table. Cumulative weights for each criterion were used in coming up with output maps using ArcGIS 10.8. Each criterion was reclassified and assigned a weighted value. Organic carbon, total nitrogen, cation exchange capacity, and potassium were found to be adequate. Topography and climate were suitable for the sunflower production. The results from land suitability gave S1 (vastly suitable), S2 (relatively suitable), and S3 (minimally suitable) of about 51% (1022 ha), 34% (671 ha), and 15% (307 ha), respectively. The suitability map in this study could be vital and helpful in management decision options. However, the criteria considered for land suitability evaluation were mainly based on the biophysical environment, and, hence, further studies can be carried out by integrating socioeconomic parameters to improve the suitability results of the study area.
Pest Population and Yield Dynamics of Selected African Indigenous Vegetables and Pulses under Different Climate-Smart Agricultural Practices in Murang’a County, Kenya
(Kenyatta University, 2024-07) Muia, Eric Muthama
Climate change and agricultural pests constitute key constraints to agricultural production in Kenya. These constraints lower the yield potential of locally grown food crops. African indigenous vegetables (AIVs) and pulses form key economically important food crops and dietary choices in Murang’a County in Kenya. Their economic potential notwithstanding, the production of AIVs and pulses is under threat due to the effects of climate change. This study determined the effects of climate-smart agricultural practices on the overall yields and pest status in AIVs and pulses in Ithanga location, Murang’a south sub county. Baseline demographics and crop cultivation data were collected using a semi-structured questionnaire from a sample of 226 respondents. Respondents were interviewed in their farms using open-ended questions to evaluate practices about the presence, diversity, challenges and farmer practices of AIVs and pulses cultivation. The studies were conducted during the short and the long rainfall seasons of 2021 and 2022. The on-farm experiments aimed to determine the effects of selected Integrated Pest management strategies (IPM) on the abundance and diversity of Arthropod pests attacking AIVs and pulses. Field experiments were set up to study the effects of selected climate-smart agricultural practices on pest’s dynamics and yields of AIVs and pulses. Five climate smart agriculture treatments were arranged in a randomized complete block design and replicated three times. Four IPM treatments were used in three replications to determine the effects of selected IPM strategies on pest’s diversity and abundance in AIVs and pulses. The study crops included; Solanum nigrum L (black nightshade), Vigna unguiculata L (cowpeas), Vigna radiate L (green grams) and Cajanus cajun L (pigeon peas). Study plots measuring 3 meters by 3 meters were set out and sowed with certified seeds from KALRO-Katumani. Sets of data were collected on pest’s damage, pest’s diversity and yield parameters. Analysis of variance tests (ANOVA) were conducted on the collected data using Genstat software version 22.0. Post hoc analysis was done to calculate significant means using Tukeys Honest significant Difference (HSD) at P< 0.05. Data obtained from the baseline survey were analyzed using IBM SPSS-28 Software. Results from the baselines survey showed that AIVs and pulses were present in the study area, and the respondents were aware that pests were attacking their crops. The logistic regression analysis showed socio-demographic variables such as the level of education, marital status and age had significant positive effect on respondent’s knowledge levels on CSAPs and pests control strategies (P≤0.05). The pest’s species diversity was determined using the Shannon Weiner Index of diversity. The results showed that, Whiteflies (Bemisia tabaci) were the most abundant pests followed by pea aphids (Aphis fabae), flower trips (Frankliniella occidentalis) and red spider mites (Tetranychus urticae) in decreasing order. The results showed plots installed with yellow and blue stick rolls had the lowest pest’s abundance and diversity while control plots recorded the most abundant and diverse pest’s species. Plots installed with sticky rolls had higher yields while the control experiment plots had the least amount of yields in both AIVs and pulses crops (P≤0.05). The results revealed that yield parameters such as plant height, number of pods and the primary yield were higher in plots installed with dry grass mulches followed by those applied with organic manure; control plots recorded the least yield parameters across the study crops (P≤0.05). The AIVs and pulses yield levels were significantly influenced by the climate smart agricultural products (CSAPs) used.
Integrated Soil Fertility Management Practices Effects on Soil Chemical Properties and Maize (Zea Mays L.) Yield in Machakos County, Kenya
(Kenyatta University, 2024-01) Wamalwa, Stephen Wanjala
Most of integrated soil fertility management (ISFM) studies have been carried out at plot level, resulting in recommendations with minimal application due to the heterogeneity of smallholder farms in semi-arid Kenya. A research study was conducted in four (4) seasons between 2016-2018 with the aim to determine the effects of selected Integrated Soil Fertility Management (ISFM) practices on soil chemical properties and maize yields at the watershed level. The ISFM treatments included combinations of maize monocrop/pigeon pea intercrop cropping system; cattle manure applied at 2 ton ha-1 ; N-P fertilizer applied as 40 kg ha-1 of diammonium phosphate (DAP 18:46) and tied ridging (TR). A completely-randomized design (CRD) was adopted with nine for the following treatments;- (1) maize monocrop & No fertilizer (control) (2) maize monocrop & DAP (3) maize monocrop, DAP & TR, (4) maize monocrop, DAP & manure (5) maize monocrop, DAP, manure & TR; (6) maize/pigeonpea intercrop & DAP, (7) maize/pigeonpea intercrop, DAP & TR, (8) maize/pigeonpea intercrop, DAP & manure, (9) maize/pigeonpea intercrop, DAP, manure & TR. Soil pH, carbon (SOC), Total nitrogen (TN) and phosphorus (P). Exchangeable Potassium (K), Calcium (Ca), Magnesium (Mg), Sodium (Na) and micros Manganese (Mn), Copper (Cu), Iron (Fe), Zinc (Zn), and maize yield data collected was subjected to analysis of variance (ANOVA) using GENSTAT version 15 and means separated using Duncan's Multiple Range Test at (LSD 0.05). Results showed that the effect of ISFM practices on soil chemical properties and maize yield varied. Organic C, TN, Ca, Na, Mn, Cu, and Fe significantly (p<0.05) increased due to imposed ISFM practices. The maize yields were higher in short rain (SR) than long rains (LR). The treatment combination DAP, manure, tied ridging with maize-pigeon pea intercrop was best in improving soil organic carbon (0.79%), total N (0.1%). The application of DAP, manure, tied ridging with sole maize resulted in organic C increase by 0.78% and total N by 0.093%. The treatment combination DAP, manure, tied ridging with maize-pigeon pea intercrop achieved the maximum maize grain yield of 2.10 ton ha-1 and 2.16 ton ha-1 in the SR 2016 and SR 2017 respectively, while in LR 2017, maize grain yield was 2.03 ton ha-1 . Further, it resulted in the most significant marginal yield increase of 0.12 t ha-1 . This increase raised the maize grain yield from 1.56 t ha-1 to 1.68 t ha-1 in 2016 and 2017 SR, respectively. This was attributed to the improved soil fertility of the watershed due to the inputs and the N supply from the biological nitrogen fixation process of pigeonpea. Farmers in semi-arid locations can only utilize 10% of the suggested inorganic nitrogen rates if they employ a combination of manure and DAP with tied ridging on maize-pigeonpea. Furthermore, it is necessary to economically validate these ISFM practices before upscaling.
Virulence, Diversity and Management of Fusarium Oxysporum F.Sp. Cubense Infecting Bananas in Selected Counties in Central and Eastern Kenya
(Kenyatta University, 2023-10) Malaka, Musime Samuel; Maina Mwangi
Banana belongs to Musaceae family and is cultivated worldwide supporting the 1ivelihood.s of many people and the economies of many countries. One of the pathogens that is significantly reducing banana yield in Kenya is Fusarium oxysporum f.sp. cubense (Foc) that causes Fusarium wilt of bananas (panama disease). There are currently no_long—term control mechanisms for panama disease. Critically, there is very little information on the distribution of Foc races in Kenya. Carbendazim based fungicides have been used as a control measure but they have not given a reliable and long term management effect. Carbendazim has a single mode of action, hence high chances of Foc developing resistance. This study determined the pathogenicity, physiological races of Foc and the in vitro and greenhouse efficacy of Trichoderma harzianum, T. asperellum and 7. viride for management of Foc. Laboratory experiments were done at the Horticulture Research Institute (HRI) in Kandara, Kenya in May 2022. The tissue culture and greenhouse experiments were done at Coffee Research Institute. The molecular work was conducted at Kenyatta University Plant Transformation Laboratory. The genomic DNA was extracted from the 7 days old monosporic fungal cultures. The PCR amplification was done using Foc specific primers for the three Foc races by targeting hypothetical protein, TEF-1a, and SIX8a gene respectively. A total of 57 isolates were collected. Conidia for pathogenicity test were harvested from 14 days old Fusarium cultures on PDA media using two layered cheese cloth, the greenhouse pathogenicity experiment was done using the root dipping method. For management in the greenhouse, the test products and Foc were applied directly into the soil. All isolates were tested in four replicates of one plant per isolate. Disease severity was recorded weekly for 20 weeks. A disease scale of 1-5 was used during data collection. In vitro efficacy of fungicides was evaluated using poisoned food technique. The fungal radial growth for in vitro efficacy was recorded daily for one week. The data on plant biomass, biological and chemical control treatments and the data on pathogenicity test experiment were subjected to one-way ANOVA. The results were compared using Student—-Newman—Keuls (SNK) test at P<0.05. All the tested isolates were virulent. The isolates that were highly pathogenic based on data on external and internal symptoms included, AP009, CV005, KL002, KL004, AP007, EM001, AP006, CV001, CV004, and AP002. Data on plant biomass revealed that the discase caused by the pathogens also decreased the plant biomass. All the test fungicides; 7. asperellum at 0.1% rate, T. viride at 0.6% rate, T. harzianum 0.1% rate, and Carbendazim (500g/1) were effective in management of Foc. The results indicated that 7. viride, T. harzianum, T. asperellum and Carbendazim (500g/1) recorded a significantly (P<0.05) higher control of Foc compared to the negative control at 58.57 %, 61.38 %, 72.68 %, and 78.94 % respectively. The percentage control of Foc using T. viride, T. harzianum, and T. asperellum, was significantly p < 0.05 lower compared (0 Carbendazim (500g/1). A total of 31 isolates collected were confirmed to belong to Foc racel. This study generated new knowledge on the diversity of Foc in banana growing regions of Central and Eastern Kenya as well as identifying potential biological control agents against panama disease. These findings will enable farmers to access a wider range of management strategies for long-term control of panama disease.
Detection and Stability Assessment of Maize Chlorotic Mottle Virus in Maize Seeds in Kenya
(Kenyatta University, 2023-10) Shango, Peter; Maina Mwangi; Shem Nchore
Viral diseases, particularly Maize chlorotic mottle virus (MCMV) co-infecting with potyviruses causes Maize lethal necrotic disease (MLND), which is a major hurdle in maize production and a threat to food security in Africa. Maize lethal necrotic disease, spread by thrips, threatens Sub-Saharan Africa's maize yield and trade. In Kenya, where maize is crucial, controlling MLND has gained importance. Kenya Plant Health Inspectorate Services (KEPHIS) tests seeds to prevent virus-causing MLND, safeguarding the market and reducing losses for farmers and seed companies due to MCMV contamination. This research aimed at finding ways through which diseased seed lots could be saved by either inactivating the MCMV thermally or quarantining the seed for a particular duration during which MCMV could inactivate. Forty samples each comprising 400 seeds of infected seed lots were used during the experiments and subjected to different treatments. Thesc included different temperatures, storage time, and assessment of germination capacities after the exposure to different temperatures and times of storage. Extraction of Ribose nucleic acid (RNA) from 400 maize seedlings which were planted per each sample was carried out using the Cetyltrimethyl Ammonium Bromide (CTAB) method and the three testing methods Enzyme-Linked Immunosorbent Assay (ELISA), Loop-mediated isothermal amplification (LAMP), and Quantitative Polymerase chain reaction (q-PCR) were feasibly analyzed for their sensitivity as well as achieving other objectives. Analysis of Variance (ANOVA) was done by use of SAS. Results showed that MCMV Joad in maize seeds significantly reduced with storage (p=0.001). An increase in temperature to 40°C led to a significant decrease in MCMYV load but with a corresponding reduction in the viability of the seeds. The results from Loop-mediated isothermal amplification (LAMP) showed the best sensitivity in MCMYV detection up to dilution factor of 10°%, followed by real-time PCR which was sensitive up to dilution factor 10* and, lastly, the ELISA which was sensitive up to 10% In conclusion, the study demonstrates that MCMYV infected maize seeds can be stored for up to three years without a significant loss in seed viability. However, it is imperativeto avoid high temperatures, such as 40°C, during storage, as they can negatively impact seed quality. This information is crucial for policy makers in developing effective disease management strategies. Seed merchants can use this knowledge to ensure seed quality and avoid cconomic losses, while farmers can benefit from understanding the appropriate storage conditions for MCMYV infected seeds to manage the virus effectively while preserving seed viability. Additionally, the routine use of Loop-mediated isothermal amplification (LAMP) and real-time PCR techniques for MCMV detection is recommended.
Evaluation of Rapid Propagation Schemes and Spacing for Optimization of Cassava Pre -Basic Seeds Production in Rwanda
(Kenyatta University, 2023-06) Uwimana, Josette; Joseph Onyango Gweyi; Silver Tumwegamire; Benjamin Danga
Abstract
Management of Crown Gall Disease in Asteraceae Flower Cuttings in Nairobi, Kiambu and Nakuru Counties, Kenya
(Kenyatta University, 2023-04) Wanza, Paul Magdalene; Maina Mwangi; Nicholas Korir
Abstract
Biology and Morphometric Characterization of Swallowtail Butterfly, Papilio Desmondi Teita and Papilio Nireus on Wild Citrus in Taita Taveta County, Kenya
(Kenyatta University, 2023-10) Genga, Cramswel Oliver; Namikoye Everlyne Samita; Ruth Kahuthia-Gathu; Esther N. Kioko
Abstract
Soil Chemical Properties and Sunflower (Helianthus Annuus L) Productivity Responses to Sunn Hemp Intercropping and Mineral Fertilizer Application in Dodoma, Tanzania
(kenyatta university, 2023) Chappa, Luciana Raphael; Jayne Mugwe; Harun Gitari
Sunflower (Helianthus annuus L.) is one of Tanzania's high-potential cash crops. Nonetheless, nutrient depletion, especially nitrogen (N), is limiting its productivity. An integrated soil fertility management technique that entails intercropping sunflower with a leguminous plant like Sunn hemp (Crotalaria juncea) and the application of mineral N fertilizer can boost N availability for crop uptake hence resulting in high crop productivity. The study was conducted in the semi-arid -Dodoma region in Tanzania where it adopted a randomized complete block design (RCBD) with six treatments each replicated four times. These treatments were T1; Control (sunflower pure stand) without mineral nitrogen (N) fertilizer, T2; Sunflower-Sunn hemp intercrop under 1:1 row ratio without fertilizer, T3; Sunflower-Sunn hemp intercrop under 1:1 row ratio with fertilizer, T4; Sunflower-Sunn hemp intercrop under 2:1 row ratio without fertilizer, T5; Sunflower-Sunn hemp intercrop under 2:1 row ratio with fertilizer and T6; Sunflower pure stand with fertilizer. Data that were collected are soil chemical properties (soil pH, organic carbon, total nitrogen, available phosphorus, potassium, calcium, magnesium, and sodium), sunflower growth and yield parameters (plant height, leaf area, number of leaves per plant, sunflower head diameter, N uptake by sunflower leaves, achene yield, number of seeds per plant, weight of seed per plant, and stover yield), economic returns (gross income, net income, and benefit-cost ratio-BCR). The data from this study were tabulated in excel and then subjected to analyses of variance. The means of treatments that were significant were distinguished by using the least significant difference (LSD) at a 95% confidence interval. The results indicated that except for soil pH, the other chemical soil properties tended to increase significantly (p ≤ 0.05) under all the treatments containing integrated approaches like Sunn hemp and N fertilizer application relative to the sunflower pure stand treatment across the sites. Regardless of the site, T6 and T3 showed the best performance based on the sunflower growth and yield. For instance, at Kongwa the sunflower leaf area was highest in T3 (285 cm2) and T6 (282 cm2) with T4 having the least value of 149 cm2. A similar trend was observed for the number of Sunflower seeds per plant, the weight of sunflower seeds per plant, Sunflower achene yield, and Sunflower stover yields with the best- performing treatments being T6 and T3. T5 and T2 had the highest (US$ 278 ha-1) and the lowest (US$ 205 ha-1) cost of production. Economically, Kongwa outperformed Bahi. Specifically, based on treatments, T3 had the highest gross income both at Kongwa (US$ 3412 ha-1) and Bahi (US$ 1756 ha-1). This translated into respective net income and BCR of US$ 1639 and 698, and 7.50 and 3.20. This study's findings will help rural poor farmers achieve better economic returns, hence reducing poverty.
Buffel (Cenchrus Ciliaris) and Sudan (Sorghum Sudanense) Grasses’ Growth, Yield and Quality Responses to Nitrogen Application in Mandera County, Kenya
(Kenyatta University, 2023) Mohamed, Aden; Harun Gitari; Mwende Ngie
Most arid and semiarid areas are bare and greatly infested with intrusive wild species. Buffel grass (Cenchrus ciliaris L.) and Sudan grass (Sorghum sudanense Piper.) are the supreme drought-tolerant grasses that are commonly grown in dry regions. Besides water, nitrogen (N) is a vital element limiting the growth, yield, and herbage quality of such grasses since it has key roles in physiological and biochemical functions in plants. Hence, this study aimed to assess the performance of Buffel and Sudan grasses under nitrogen fertilization in Mandera County. This study comprised a field trial laid as a split-plot in a randomized complete block design with grasses being assigned to the main plots, whereas N rates (0, 35, 70, 105, and 140 kg N ha-1) occupied the subplots. Data collection was carried out on growth parameters (plant height, leaf length, number of leaves per plant, leaf width, stem girth, and tiller number), yield parameters (shoot weight, root weight, and aboveground biomass yield DBY), and quality attributes (acid detergent fiber ADF, crude protein CP, and neutral detergent fiber NDF). Across the seasons, plant height progressively increased with increasing N rates up to a maximum of 141 and 246 cm for Buffel grass and Sudan grass, respectively, which were associated with a 105 kg N ha−1 rate. Nonetheless, there was no noteworthy enhancement in plant height (142 and 246 cm) with an additional upsurge in N fertilizer rate to 140 kg N ha−1 relative to the one of 105 kg N ha−1. Regarding the leaf length, Sudan grass had longer and wider leaves at all treatment levels than the Buffel grass. Plant height, leaf length, width, and the number of leaves per plant increased with increasing N level up to the rate of 140 kg N ha-1, though this was not statistically different from the rate of 105 kg N ha−1, for both kinds of grasses. The results revealed that Sudan grass contained higher crude protein than Buffel grass at all levels of treatments (10.33 and 8.80% at the rate of 105 kg N ha−1 respectively). More so, crude protein content was found to be higher in plots where N application was made than in the control plots. There were great associations between the dependent variables (DBY, ADF, NDF, and CP) and independent variables (plant height, leaf length, No. of leaves, leaf width, stem girth, and No. of tillers), with the coefficient of regression ranging from 0.56 to 0.96 for Buffel grass and 0.59 to 0.96 for Sudan grass. Findings from this study indicate that for optimal growth, yield, and nutrient content benefits, Buffel and Sudan grasses ought to be grown using nitrogen fertilizer at 105 kg N ha−1 rate. The study recommends the use of nitrogen fertilizer at the right time in the growth cycle of Buffel and Sudan grasses.
On- farm integrated management of fruit flies (tephritidae) infesting pumpkins (cucurbita maxima duch.) in Yatta and Masinga Sub- Counties of Machakos County, Kenya
(Kenyatta University, 2023) Waithaka, Alice Nduta; Namikoye Everlyne Samita; Mary Mwari Guantai; Muo KASINA
Pumpkin is an economically important crop in Machakos County. The crop is highly nutritious, mainly grown by smallholder farmers for household use. Their production is however constrained by fruit fly infestations particularly the melon fly, Zeugodacus cucurbitae (Coq.). The current study focused on the on-farm integrated management of fruit flies infesting pumpkins Cucurbita maxima in Yatta and Masinga Sub- Counties. The key objectives of the study were: (1) determining farmers’ knowledge, perception and control strategies of fruit flies infesting cucurbits in Machakos County, (2) determining the presence and onset of fruit flies on pumpkin farms in Machakos County and (3) evaluating the effect of integrated pest management (IPM) strategies on the pest density and overall yield of pumpkin. In the first objective, a household survey of 95 cucurbit farmers was conducted using structured questionnaires. In the achievement of the second and third objectives, on- field experiments were carried out in the low and medium NDVI classes, across Yatta and Masinga Sub- Counties. The experiments were conducted for two growing seasons (October 2019-March 2020 and March 2020-July 2020). Two treatments were used for the third objective; IPM and control replicated eight times in each NDVI class. The IPM package comprised of lynfield traps with cuelure® laced with malathion®, Metarhizium anisopliae strain ICIPE 69 (mazao campaign®), and fruit fly mania™, a protein bait incorporating spinosad (tracer®). The collected data was analyzed using the statistical package for social sciences (SPSS) and R software. The farmer respondents were not aware of IPM strategies for fruit fly control (91.4%). However, 48.8% of the them reported lack of training as the main constrain hindering adoption of IPM practices. Most of the respondents 75.5% therefore relied on chemical insecticides use for fruit fly management. In the first season, fruit flies were reported in pumpkin plots from the second week of flowering across both NDVI classes. However, in the second season, fruit flies were reported in the farms from the first week of flowering. Zeugodacus cucurbitae was the most abundant fruit fly species from trap catches (75%) and fruit incubation (69.01%). Although, Z. cucurbitae catches/trap/day were significantly higher in control plots than in IPM plots, the yields did not differ significantly between the treatments. In conclusion, the study states lack of training as the major constraint inhibiting adoption of IPM for fruit fly management in the County. The study concludes that fruit fly infestations by Z. cucurbitae starts as early as the onset of flowering especially when suitable host is present after temporarily being absent. Additionally, the use of IPM plan significantly reduced fruit fly population. The study therefore recommends training on the IPM strategies be conducted to equip cucurbit farmers’ as independent decision- makers in pest management. Farmers should initiate fruit fly management as soon the crops start flowering to minimize yield losses. Finally, awareness on the effectiveness of the IPM plan should be promoted widely among cucurbit farmers to enhance adoption.
Potato (solanum tuberosum l.) growth and yield as influenced by bioslurry and inorganic fertilizer in Taita Taveta County, Kenya
(Kenyatta University, 2023) Mwakidoshi, Emmanuel Randy; Harun Gitari; Esther Muindi
Biogas slurry procured from livestock refuse after bio digestion has a great potential of mitigating climate change by reducing methane gas emission from manure use and nitrous oxide from inorganic fertilizer use thus, improving crop growth, yield, and soil productivity. A field study was conducted on farmer’s fields at Werugha and Wusi-Kishamba wards in Taita Taveta County, Kenya to investigate the effect of inorganic fertilizer and bioslurry on potatoes (Solanum tuberosum L.) growth and yield. Four treatments: bioslurry + DAP (Di-ammonium phosphate); sole bioslurry, sole fertilizer (DAP), and control (without amendment) were laid out in a Randomized Complete Block Design with five replications. 100% DAP [18:46:0] fertilizer was used at a rate of (5g/hill) and 100% Bioslurry was applied at rates of (400mls/hill) at planting. In addition, a survey questionnaire was developed and administered to 120 smallscale farmers within the two wards. Biophysical data was collected on plant growth (plant height, leaf length, and the number of leaves per plant), and yield (marketable and unmarketable tubers, and the number of tubers plant−1). The survey and biophysical data obtained from the study were analyzed using Statistical Package for the Social Sciences (SPSS) and GenStat statistical software, respectively at a 5% probability threshold. Results showed that the use of bioslurry had not been well adopted by farmers from the two wards as only 18% responded to using bioslurry on their farms whereas 78% relied on chemical fertilizers and other forms of manures such as farmyard manure. However, even those using slurry had since been reported to have challenges with the use and application of the slurry. The 36% of farmers who applied bioslurry alone did so due to its availability considering the high cost of inorganic fertilizers while those who combined it with inorganic fertilizers had faith in chemical fertilizers and that they aimed at achieving high crop yields. The major challenges farmers faced while using slurry on their farms were reported to be on lack of knowledge on the exact quantity to be applied per unit area and on the storage of excess slurry from biodigesters. This implied that even though slurry was available, it was still not useful to the farmers due to under/over application and poor storage. The field experiment reviewed that the application of combined bioslurry and DAP fertilizer significantly (p ≤ 0.05) improved potato growth and yield. The results indicated the superiority of combined bioslurry + DAP fertilizer use over the sole application of either of the two amendments. For instance, the plants that received these inputs in combination were taller (80 cm) than either those treated with sole slurry (61 cm) or sole fertilizer (66 cm). Subsequently, this resulted in a higher (23.3 t ha−1) total yield in bioslurry + DAP treatment compared to respective intermediate values of 16.8 and 18.7 t ha−1 for sole slurry and sole fertilizer and the least record of 14.2 t ha−1 in control. The study, therefore, recommends the synergistic application of bioslurry and inorganic fertilizer (DAP) to potato crops for optimal crop growth and production
Optimizing soybean yield, phosphorus use efficiency, and economic returns using phosphatic fertilizer and inoculation with bradyrhizobium japonicum in lira city, Uganda
(Kenyatta University, 2023) Akello, Mirriam; Jayne Mugwe; Harun Gitari
Soybean (Glycine max L. Merril) is among the key oil seed crops worldwide providing several benefits from human consumption to the enhancement of soil productivity. The major bottleneck to the crop’s production in the tropics is the decreasing soil fertility, mainly caused by not only low nitrogen (N) but also phosphorus (P) levels in the soil. There is a high potential for supplying N from the atmosphere through biological nitrogen fixation (BNF), a natural process mediated by the symbiotic bacteria Bradyrhizobia Japonicum, which requires optimum P levels for effective N fixation. The study focused on assessing the synergistic effect of inoculation and phosphatic fertilizer application on nodulation, yields, economic returns, P uptake and use efficacy of Maksoy 5N soybean. The study was conducted at Ngetta Zonal Agricultural Research and Development Institute (NGEZARDI) located in Lira City, Uganda. The study had the experiment laid out in RCBD under a split-plot arrangement with the main plots being two inoculation levels (with or without inoculation) and the sub-plots being phosphatic (TSP) inorganic fertilizer at four P levels: 0, 7.5, 15, and 45 kg P ha-1. The treatments were replicated three times. The data collected included growth and yield parameters, such as the total number of root nodules, number of effective root nodules, number of seeds per pod, number of pods per plant, biomass yield, stover weight, grain yield, and 100-grain weight. Production cost and yield data were used to calculate economic returns. Data collected were subjected to analysis of variance in Genstat software where the treatment means were further distinguished at a 5% level of probability using Fishers' least significant difference. The total and effective root nodules increased with inoculation with a peak in fertilized plots with 15 kg P ha-1 (11.8, 13.3). Under inoculation and P application, treatments that received 7.5, 15 and 45 kg P ha-1 recorded 9, 30, and 25% higher yields than the control. The highest net income and benefit: cost ratio were recorded in the inoculated and fertilized plots with 15 kg P ha-1 (US$ 414.93, 1.87) and (US$ 390.23, 1.76). With inoculation, P use efficiency based on yield (PUEY) and economic returns (PUEE) decreased with increasing P levels in the orders of 165 > 73 > 54 > 21 kg grain kg P supplied-1 and 51 > 24 > 20 > 8 US $ kg P supplied-1 for the control, P7.5, P15, and P45 respectively. This study indicated that for optimal growth, productivity, and economic benefits, soybean ought to be inoculated with Bradyrhizobium coupled with the application of phosphatic fertilizer at the rate of 15 kg P ha-1.
Ex-Ante Assessment Of Willingness To Pay For Larvae Spy As Cereals’ Pest Early Warning Acoustic Technology In Kenya
(Kenyatta University, 2022) Mundumwiu, Kitheka; Ibrahim Macharia.; Menale Kassie
The current existing Post-Harvest Losses (PHLs) mitigation measures being used by grain store managers and traders are basically physical hence inefficient for timely insects’ detection and monitoring. The introduction of alternative but effective equipment for monitoring and early detection of insect pest populations’ grain storage is essential. Development of a technology without its adoption is meaningless hence the need to establish ex-ante willingness to pay for the larvae spy device. The main objective of this study was to assess the ex-ante Willingness to Pay (WTP) for the Larvae Spy device by grains store managers and traders in Kenya. The specific objectives were; (i) to estimate facility managers’ and traders’ WTP for the larvae spy device in Kenya, (ii) to compare the WTP for the Larvae Spy by cereals store managers and traders in Machakos, Nakuru and Nairobi counties in Kenya and (iii) to determine the factors influencing the managers’ and traders’ WTP for the larvae spy device in Kenya. Interview-based primary quantitative and qualitative data were collected using a semi-structured questionnaire from 139 cereals store managers and traders in 3 counties in Kenya (Machakos, Nakuru and Nairobi) as a representative of counties with high number of cereals stores. Double-Bounded Dichotomous Choice Model was used to estimate the managers’ and traders’ WTP. To compare the WTP for managers and traders in the three sampled counties, a chi-square test was used. Logistic regression was used to assess factors influencing WTP. The Cox and Snell R square results of the binary logistic regression on the store managers and cereal traders indicate that there was 31% probability of the larvae spy acoustic technology being adopted by the cereals store managers and traders in Kenya at a price of KSh 80,000. The calculated chi-square was found to be significant; hence, not rejecting the null hypothesis that there is no statistically significant difference in WTP between managers and traders in the three sampled counties. The WTP is determined by education level, expected availability and affordability of the device, expected risk reduction potential by the device, labour requirement by the device, trend of PHLs caused by pests and capacity of the facility. The major impediment to the technology adoption was attributed to the high Larvae Spy acoustic technology prototype price. The results suggest that the design and development of the final larvae spy acoustic technology should consider the price for market penetration. If the manufacturer decides to introduce the technology into the Kenya market at the prototype price used for this research, then they should target large cereals stores, make the technology available and affordable and target stores run by managers and traders who have acquired some significant level of education. Finally, the study recommends that policy intervention aimed at addressing food insecurity should support grain pest detection acoustic technologies adoption to grain handlers for prompt and timely grain pests control measures.
Characterization and Fungicide Sensitivity of Tomato Isolates of Alternaria Solani Sorauer in Kajiado, Kiambu and Kirinyaga Counties, Kenya
(Kenyatta University, 2022) Nuwamanya, Andrew; Maina Mwangi; Steven Runo
Early blight (EB) caused by Alternaria solani is ranked as one of the most important tomato diseases in Kenya and farmers predominantly rely on synthetic fungicides to control it. However, there have been reports about the declining efficacy of some fungicides against EB control. This study was carried out to (i) determine the occurrence, importance and current management practices for tomato EB in Kirinyaga, Kajiado and Kiambu counties, Kenya; (ii) characterize Alternaria solani tomato isolates from the selected counties by morphological features and sensitivity to two commonly used fungicide groups and (iii) determine occurrence and spatial distribution of resistance-associated mutations in A. solani isolates from the three counties. A baseline survey was carried out in 175 tomato fields in Kirinyaga (n=58), Kajiado (77) and Kiambu (40) counties, data was collected using semi-structured questionnaires and field observation. Tomato shoots showing typical EB symptoms were collected from surveyed fields (one per field) and carried to Kenyatta University Pathology Laboratory, where a total of 96 A. solani isolates were isolated. Results indicate that EB was highly prevalent (75-91%) in all regions and all farmers were controlling it by fungicide application. A total of 40 fungicide products, representing 20 active compounds, with varying resistance risk levels, were in use against EB. Most farmers (83%) were applying the fungicides at higher than the recommended doses. Most farmers (81%) reported declines in effectiveness of fungicides, especially strobilurins and triazoles. The Alternaria solani isolates were characterized based on cultural features, conidial morphology and sensitivity to two fungicides; azoxystrobin (a strobilurin) and difenoconazole (a triazole) in vitro by poisoned food technique. One way analysis of variance revealed that colony and conidial parameters of isolates did not differ significantly (at α=0.05) across the study counties. Isolates were considered resistant to the fungicide whenever their % Mycelial Growth Inhibition (%MGI) at manufacturer’s recommended dosage was below 50% and sensitive when above 50%. While all isolates were susceptible to Difenoconazole, majority of them (64%) were resistant to Azoxystrobin. Locations significantly differed in regard to sensitivity of isolates to fungicides with Kajiado and Kirinyaga isolates being least sensitive to Azoxystrobin and Difenoconazole, respectively. To determine the genetic basis of Azoxystrobin resistance, the cytochrome b gene (in all isolates) was PCR amplified, sequenced and analyzed for resistance-associated mutations at amino acid positions 129, 137 and 143. The F129L mutation was present in all Azoxystrobin resistant isolates plus 10 susceptible ones with MGI values close to the 50% threshold. Kajiado county had the highest percentage of mutated isolates (96.8%), followed by Kirinyaga (70%) and lastly Kiambu (40%). These findings indicate that Kenya’s A. solani populations have developed resistance to some fungicides by mutation. The study recommends that anti-fungicide resistance strategies should be applied, for more effective management of tomato early blight.
Assessment of Germination Potential and Population Status of Melia Volkensii Gürke in Kitui County, Kenya
(Kenyatta University, 2022) Njehu, Mukami Jane; Emily Wabuyele
Melia volkensii Gürke is a native tree species that grows in the arid and semi-arid areas of East Africa. There has been overutilization of this tree which may lead to risk of rapid decrease in its community and genetic diversity. Additionally, planning and implementing planting programmes and conservation plans of M. volkensii have been hindered by insufficient knowledge on its seed storage behavior. This study sought to develop optimal protocols for seed germination and assess population status of Melia volkensii to enhance conservation and supply chain management in Kitui County. Melia volkensii fruits were collected from Tiva Forest and the germination experiment was carried out in KEFRI Kitui within nursery conditions. Seed germination experiments were arranged in a completely randomized design with three factors – extraction state, storage container and storage temperature. For extraction, seeds were divided into two lots – extracted seeds and unextracted seed (nut). Two types of storage containers were used namely sealed and unsealed. The storage temperatures were room temperature (30oC) and cold storage (-20oC). Germination tests were done before storage, and later after 2, 4 and 6 months in storage from each of the storage conditions. A hundred seeds and nuts each were sown for each experimental unit. The rate of seedling sprouting was recorded for a duration of 10 days as a percentage of seeds sown. Variation in germination percentages “was tested using two-way analysis of variance (ANOVA) at 95 % confidence interval and means separated using fisher’s protected least significant difference” in R and SAS statistical software. The highest percentage (89 %) was scored in nuts kept in unsealed containers at 30oC at 6 months and the lowest (14 %) in seeds stored in similar conditions for 2 months.The differences were significant. These results indicate that the germination rates of M. volkensii seeds increased with increase in period of storage. Additionally, plant population was determined in situ across seven transect lines measuring 1050 meters in length. Sampling was carried out in five plots measuring 50 x 50 m established at intervals of 200 meters. Transect 1 and 7 were laid in farmland while the transects between these two were laid in bushland. All tree species represented in each plot were counted. “Height and diameter at breast height (DBH) were measured for all M. volkensii trees within the plots. Melia volkensii seedlings and coppices were counted in 5 x 5 m nested plots within the larger plots. One-way analysis of variance (ANOVA) at 95 % confidence interval was used to test for variance in parameters measured and means separated using Tukey’s HSD. There were significant differences in height and DBH” means of M. volkensii among transects. Transect 2 had the lowest mean height and DBH while the tallest trees were in transects 1, 3, 4, and 6. Transect 1 had highest mean DBH. Means of seedlings were not significantly different among transects. Coppicing was significantly highest in transects 1 and 4. Moreover, relative abundance, species richness and diversity of plant species observed were analyzed “using Simpson’s index of biodiversity and Shannon-Wiener species diversity index. Melia volkensii was the most frequently occurring species with 12.2% (n=67) followed by Acacia tortilis10.0 % (n=55). Calotropis strophela, Commiphora capensis, Maerua crassifolia were the least represented relative abundance of 0.18 %. Values of indices used varied among transects and did not follow the location of transect implying that diversity was not determined by land disturbance. In conclusion, nuts stored unsealed at room temperature have the highest longevity. Based on diversity and relative abundance of M. volkensii and associated tree species in the study area, tree exploitation in Kasaala Location does not cause
Characterization and Fungicide Sensitivity of Tomato Isolates of Alternaria Solani Sorauer in Kajiado, Kiambu and Kirinyaga Counties, Kenya
(Kenyatta University, 2022) Nuwamanya, Andrew; Maina Mwangi; Steven Runo
Early blight (EB) caused by Alternaria solani is ranked as one of the most important tomato diseases in Kenya and farmers predominantly rely on synthetic fungicides to control it. However, there have been reports about the declining efficacy of some fungicides against EB control. This study was carried out to (i) determine the occurrence, importance and current management practices for tomato EB in Kirinyaga, Kajiado and Kiambu counties, Kenya; (ii) characterize Alternaria solani tomato isolates from the selected counties by morphological features and sensitivity to two commonly used fungicide groups and (iii) determine occurrence and spatial distribution of resistance-associated mutations in A. solani isolates from the three counties. A baseline survey was carried out in 175 tomato fields in Kirinyaga (n=58), Kajiado (77) and Kiambu (40) counties, data was collected using semi-structured questionnaires and field observation. Tomato shoots showing typical EB symptoms were collected from surveyed fields (one per field) and carried to Kenyatta University Pathology Laboratory, where a total of 96 A. solani isolates were isolated. Results indicate that EB was highly prevalent (75-91%) in all regions and all farmers were controlling it by fungicide application. A total of 40 fungicide products, representing 20 active compounds, with varying resistance risk levels, were in use against EB. Most farmers (83%) were applying the fungicides at higher than the recommended doses. Most farmers (81%) reported declines in effectiveness of fungicides, especially strobilurins and triazoles. The Alternaria solani isolates were characterized based on cultural features, conidial morphology and sensitivity to two fungicides; azoxystrobin (a strobilurin) and difenoconazole (a triazole) in vitro by poisoned food technique. One way analysis of variance revealed that colony and conidial parameters of isolates did not differ significantly (at α=0.05) across the study counties. Isolates were considered resistant to the fungicide whenever their % Mycelial Growth Inhibition (%MGI) at manufacturer’s recommended dosage was below 50% and sensitive when above 50%. While all isolates were susceptible to Difenoconazole, majority of them (64%) were resistant to Azoxystrobin. Locations significantly differed in regard to sensitivity of isolates to fungicides with Kajiado and Kirinyaga isolates being least sensitive to Azoxystrobin and Difenoconazole, respectively. To determine the genetic basis of Azoxystrobin resistance, the cytochrome b gene (in all isolates) was PCR amplified, sequenced and analyzed for resistance-associated mutations at amino acid positions 129, 137 and 143. The F129L mutation was present in all Azoxystrobin resistant isolates plus 10 susceptible ones with MGI values close to the 50% threshold. Kajiado county had the highest percentage of mutated isolates (96.8%), followed by Kirinyaga (70%) and lastly Kiambu (40%). These findings indicate that Kenya’s A. solani populations have developed resistance to some fungicides by mutation. The study recommends that anti-fungicide resistance strategies should be applied, for more effective management of tomato early blight.
Correlation between Maize Lethal Necrosis Disease and Mycotoxin in Maize in Bomet, Narok and Nakuru Counties, Kenya.
(Kenyatta University, 2021) Mwasame, Evans Natembeya; Maina mwangi; Catherene Taracha
Maize Lethal Necrosis Disease (MLND) is believed to increase concomitant toxic fungal infections in maize. The goal of this study was to discover a link between MLND and fungal infections. During the 2018/2019 maize growing seasons, a Randomized Complete Block Design experiment with three replicates was set up in farmer's fields in three experimental sites in Bomet, Narok, and Nakuru Counties. Six hybrid maize varieties classified as resistant (KATEH16-02 and DK777), tolerant (WE5135 and WE5140), and susceptible (DUMA 43 and PH30G-20) to MLND were used. A total of 54 maize grain samples were collected. Fungal colonies were isolated on Potato Dextrose Agar medium and identified using morphological and microscopic techniques. ELISA test was used to quantify aflatoxins. The samples yielded 4561 fungal isolates, with Fusarium being the most predominant genus (79.75%), followed by Penicillium (16.03%) and Aspergillus (1.933%). A positive significant correlation between the MLND bioassay score, Penicilium and Aspergillus infection was achieved, (r = 0.429, p =0.001) and (r = 0.275, P =0.5) respectively. Aflatoxin concentration levels of between 0.3 and 2.8 μg/kg were detected in 38.89 % of the samples. Aflatoxin and MLND were significantly correlated (p =0.001, r2=0.547). Although this study was only able to show Aflatoxins, there is a strong likelihood of other mycotoxins occurring in maize grains in higher proportions. Therefore the public should be made aware of the mycotoxin risks associated with consumption of MLND infected maize.
Physico-Chemical Parameters, Bacterial Load And Heavy Metals, in Water and Vegetables Grown along Mitheu River, Machakos County, Kenya
(Kenyatta University, 2022) Kitulu, Linge; Esther Kitur; Julius Nzeve; Fuchaka Waswa
Urban streams are increasingly utilized for irrigation farming to supplement the demand for food in cities, and towns. The susceptibility of these streams getting polluted by improperly treated industrial, and municipal effluent is high. The objective of this study was to investigate the bacteriological, and heavy metals contamination in Mitheu stream within Machakos municipality, and concentration of selected heavy metals in vegetables irrigated with water from the stream in order to contribute to measures towards safe disposal of effluent. This study investigated the water quality of Mitheu stream with respect to irrigation use, and the levels of selected heavy metals in Kales, and Spinach grown along the stream. Bacterial counts, physico-chemical parameters i.e., temperature, pH, Total Dissolved Solids (TDS), Electrical Conductivity (EC), chemical Oxygen Demand (COD), Biological Oxygen Demand (BOD), nitrates, phosphates, and sulphates as well as selected heavy metals i.e., Cd, Cu, Zn, Pb, and Cr were analyzed in water. The concentration of these selected heavy metals in kales, and spinach were determined as well. water samples for physico-chemical, heavy metals, and bacteriological analyses were collected in four selected sampling points along Mitheu stream once every month from June to September 2019. Kales, and Spinach samples for heavy metals analysis were collected from farms along the stream adjacent to the selected sampling points. Physico-chemical, and bacteriological analyses were performed in Water Resources Authority Laboratory in Nairobi. Heavy metals analyses in both water, and vegetables were performed in Kenya Plant Health Inspectorate Services Analytical Laboratory in Nairobi. The results were subjected to One-Way Analysis of Variance to test significant differences. Comparison with WHO standards for the respective parameters was done to test suitability of the stream water for irrigation, and the vegetables for human consumption. The stream was found to contain higher-than-recommended levels of pH, TDS, EC, COD, BOD, and Bacterial contaminants. Concentrations of nitrates, and cadmium (Cd) in the stream were also higher than WHO safe limits for irrigation water. Concentrations of COD, BOD, and Total Coliforms bacteria had significant variation along the stream (p≤ 0.05). All other parameters investigated, were not significantly varied along the stream. The concentrations of Cd, Pb, and Cr in kales, and spinach exceeded WHO recommended limits. There was no significant correlation between the concentration of heavy metals in water, and in vegetables except for Cu. These findings implied inefficiency in the effluent management system within Machakos municipality. They further indicated that the stream was not fit for use in irrigation farming as it presented a health hazard from bacterial infections, organic chemicals as well as cadmium poisoning to the farmers, and consumers of their produce. Vegetables grown along this stream were also unsuitable for consumption as they threatened the health of consumers via Cd, Pb, and Cr poisoning. The County Government of Machakos working together with the National Environment Management Authority need to take appropriate measures to curb untreated effluent discharge into the stream. Public sensitization of residents of Machakos municipality with respect to the health implications of farming with heavily polluted water is also recommended.
Evaluation of Pre- Emergence Herbicides for Control of Annual Grass and Broad-Leaved Weeds in Finger Millet Elusine Coracana in Kakamega County, Kenya
(2022) Mayaka, Justus Mogaka; Nicholas Korir; Joseph Gweyi
Finger millet is an important crop worldwide due to its nutritive and cultural qualities. Production in Kenya has declined due to poor weed management which has always been hampered by heavy rains and also lack of labor for hand weeding. More so because weeding is mostly done outside the critical period of control leading to huge yield losses. This study aimed to evaluate the effectiveness of selected pre-emergence herbicides in control of common annual grass and broadleaved weeds in finger millet production. The specific objectives were; to determine growth and yield of finger millet under different weed control methods; to compare changes in the total weed biomass under different weed control methods, and to determine the effects of pre- emergence herbicide and their rates on grasses and broad leaf weeds. The experimental design was randomized complete block design with three replications. The experimental plots measuring 2 by 2 meters were laid down and the five treatments, that is commercially available pre- emergence herbicides (Pendimethalin, Metribuzin, Atrazine, Metolachlor and Dimethyl amine) were applied at uniform dosages of 1, 1.5 and 2 L/ha per each. The control treatments included plots managed using hand weeding and no weeding. Data was collected on the number of weed species, weed biomass, number of basal tillers, herbicide phytotoxicity, weed and crop heights, number of panicles, weight of panicles, weight of un-threshed and threshed grains and 1000 grain weight. The data was analyzed using GenStat version 15.1 and different means were separated using Tukey‘s test at P<-0.05. Results indicate that all the tested pre-emergence herbicides were effective in the control of annual grass and broadleaved weeds in finger millet than hand weeding and no weeding methods. Application of Pendimethalin at 1.5 and 2.0 L/ha Active Ingredient (AI), resulted in weed optimal control and least phytotoxicity. Results also indicated that the height of finger millet was significant where the herbicides were applied. Lower weed biomass was also positively correlated with higher crop height, more panicles, high unthreshed and threshed weights and a 1000 grain weight. Weed control using pre emergence herbicides significantly (p < 0.001) increased the yields of finger millet. Pendimethalin and atrazine at 1.5 and 2 L/ha rate were the best with regard to the control of annual grass and broad leafed weeds in finger millet. Chemical weeding of finger millet especially by use of pendimethalin at 1.5 and 2 L/ha is therefore recommended. Further studies to determine the effectiveness of these herbicides against the weeds of finger millet in different agro-ecological zones as well as on other varieties of finger millet.

Browse

Recent Submissions