https://repository.ju.edu.et//handle/123456789/143 2026-04-20T08:18:49Z https://repository.ju.edu.et//handle/123456789/10114 Parasitic Nematodes and Fusarium Wilt Of Hot Peppers (Capsicum Spp.) And Their Management Using Endospore Forming Rhizobacteria in Jimma Zone, Southwest Ethiopia Shiferaw Demissie Tola; Beira H. Meressa; Diriba Muleta; Fassil Assefa Hot pepper is a popular crop in Ethiopia, widely cultivated for consumption and as a significant source of income for smallholder farmers. It also contributes to the overall economy of the country. Among vegetables and spices, pepper ranks first in terms of area under cultivation and production. However, the crop's production and productivity are often constrained by wilt causing pathogens such as Fusarium wilt and root-knot nematode (RKN), particularly during certain seasons. These issues significantly limit Ethiopia's contribution to global markets. Between 2017 and 2022, a comprehensive study was conducted to investigate the occurrence and distribution of plant-parasitic nematodes infecting hot peppers. The study also evaluated the population dynamics and damage threshold of Meloidogyne incognita, assessed the reactions of hot pepper varieties to Fusarium oxysporum and M. incognita, and examined the effectiveness of endospore-forming bacteria from the pepper rhizosphere in controlling these pathogens under both in vitro and in vivo conditions. Soil and plant samples were collected from four major pepper-growing districts in the Jimma Zone. Microbial characterization was performed in the Research and Postgraduate Laboratory of the Department of Biology, while nematode processing, soil physicochemical analyses, and pot experiments were conducted at the College of Agricultural and Veterinary Medicine, Jimma University. Molecular analyses of Meloidogyne isolates were conducted at Ghent University, while those of Fusarium and bacterial isolates were performed at the Swedish University of Agricultural Sciences. Data collected during the study were analyzed using Minitab® version 19, R-4.2.1, SAS version 9.3, and Origin Pro 202. Over 83% of surveyed pepper fields were found to be infested with parasitic nematodes, and 13 nematode types were identified. Among these, Meloidogyne, Scutellonema, Rotylenchulus, Helicotylenchus, Pratylenchus, and Rotylenchus were the most prevalent, with Meloidogyne (identified as M. incognita through Nad5 gene analysis) being the most common. This represents the first report of M. incognita on pepper crops in Ethiopia. The damage potential of M. incognita was investigated through greenhouse experiments, using 13 initial population densities (Pi). The "Dinsire" variety showed a tolerance limit for total fresh weight and fruit number at xvii 0.30 and 0.18 M. incognita (g soil)-1, respectively. Results indicated a negative correlation between Pi and both plant growth and the final nematode population density (Pf). The study estimated the maximum multiplication rate (a) and maximum population density (M) of M. incognita at 8813.2 and 3420.1 M. incognita (g soil)-1, espectively. The "Dinsire" variety performed well at a Pi of fewer than 8 second-stage juveniles (J2) (g soil)−1, exceeding the field average of 6 nematodes (g soil)−1. Fusarium isolates from infected pepper samples were identified as F. oxysporum using ITS region analysis. Among these, the isolate FI1 was highly pathogenic, significantly affecting the "Mareko Fana" variety under greenhouse conditions. Of the 11 varieties tested, "Melka Dera" was resistant to FI1, while "Melka Zala" was highly susceptible, experiencing a 66% reduction in fresh root weight and a 61% reduction in fresh shoot weight. Most pepper varieties currently under production are susceptible to Fusarium wilt, underscoring the need for further screening of genotypes and the development of effective management strategies. From 48 soil samples taken from healthy pepper rhizospheres, 35 endospore-forming bacteria were identified, exhibiting multiple plant growth-promoting traits. These included phosphate solubilization (indices ranging from 2.8 to 10), indole acetic acid production (27.31–59.16 µg/ml), and chitin hydrolysis (chitinolytic indices of 1–7.5 in 20 isolates). Of these, 21 bacterial isolates reduced pathogenic Fusarium growth by 39.4–79.2%, while 12 inhibited M. incognita egg hatching by 51–96.4% and increased nematode J2 mortality by 45–98.7%. Molecular analyses identified these bacteria as Bacillus siamensis, B. velezensis, B. cereus, and Paenibacillus polymyxa. Bacillus cereus (JUBC7) and B. siamensis (JUBC12) demonstrated strong potential for producing plant growth-promoting substances and antagonizing F. oxysporum and M. incognita in vitro. Greenhouse evaluations of 12 pepper genotypes found that the "Dinsire" variety suppressed M. incognita populations, while "Bako Local" and "Dame" were highly susceptible. Co-inoculation of B. cereus and B. siamensis reduced co-infection by M. incognita and F. oxysporum by 92.6%, with B. cereus alone suppressing Fusarium infection by 90.1%. Based on these findings, the "Dinsire" variety, in combination with B. cereus and B. siamensis, is recommended as an integrated pest management strategy for fields infested with Fusarium wilt and M. incognita, pending further validation under field conditions. 2025-01-06T00:00:00Z https://repository.ju.edu.et//handle/123456789/10107 Assessing Soil and Water Conservation Practices and Factors Affecting its Adoption in Soro District, Hadiya Zone Central Ethiopia Region Zewdu Mirkeno; Tadesse Mosissa; Amsalu Tilahun Soil is the most important natural resources which support all fauna and flora of the world. The whole creation depends on the soil which is the ultimate foundation of life existence. Soil erosion is a global environmental problem causing the loss of fertile topsoil and reducing the productive capacity of the land or soil and there by raises the risk of the global food security. Soil erosion by water is one of the principal causes of land degradation, food insecurity and largely remains a major constraint to agricultural development in developing countries. Soil and water conservation practices help to control runoff and prevent loss of soil by soil erosion. The aim of this study was to assess soil and water conservation practices and factors influencing its adoption among rural households in Soro district, Hadiya Zone, Central Ethiopia Region. Both primary and secondary data were used in this study. Descriptive analysis and binary logit regression model were used to analyze the collected data. Descriptive analysis showed contour plough, soil bund, fanyajuu and waterways were important physical soil and water conservation practices whereas crop rotation, planting trees and mixed cropping were used as main biological soil and water conservation methods used among smallholder farmers in the study area. Using trash for gulley control and planting local trees species were preferable indigenous soil and water conservation practices which were highly implemented in the study area. Moreover, sex, education level, land size, extension contact, training on soil and water conservation practices and household total income were significantly (p<0.05) and positively affected households’ adoption of soil and water conservation practices. Based on the findings we suggest that governmental organizations and non-governmental organizations in broad spectrum should need to focus on promoting agricultural production and land productivity, decreasing land degradation and soil erosion by adoption of soil and water conservation practices through provision and strengthening farmers’ education, training on soil and water conservation practices, provision and strengthening extension service among small holder farmers in the study area. 2025-08-27T00:00:00Z https://repository.ju.edu.et//handle/123456789/10106 Assessment of Above and Belowground Carbon Storage along altitudinal gradient in Baja Natural Forest, Chora District, Southwest Ethiopia Zeriye Ayele Wolde; Abebayehu Aticho; Zerihun Kebebew Forest plays an important role in the global carbon cycle as carbon sinks of the terrestrial ecosystem. Carbon stock estimation enables us to understand carbon stocks' current status and derive its near-future changes. This study was carried out to assess the carbon pool of the Baja Natural forest along altitudinal gradients in Chora Woreda, Southwest Ethiopia. The sampling sites were selected by dropping a regular interval of 25 m elevation gradient. From each sampling site, three quadrats 25 m apart from each other were established. A total of 48 rectangular plots of 20 m x 50 m were used to collect tree biomass data. Within these plots, three 1m2 subplots at the diagonal line of the subplots were used to collect soil and litter. The soil carbon was determined using the Walkley -Black loss on ignition method. The mean total carbon density of the forest was 374.45 ton ha-1. This is equivalent to 1374.23 t ha-1 of CO2. The mean carbon stocks at the middle altitude (428.66 ton ha-1) were estimated as greater in all carbon pools. The carbon density of the Baja Natural forest can be considered medium when compared with other studies done elsewhere in the tropics. So the study highlights that middle altitude areas store more carbon than lower and higher altitudes, and that the forest's litter biomass plays a crucial role in overall carbon dynamics. The findings underscore the importance of preserving such forests for their biodiversity conservation and carbon sequestration potential, which are vital for mitigating climate change. 2025-03-27T00:00:00Z https://repository.ju.edu.et//handle/123456789/10105 Assessing the Impacts of Eucalyptus Plantation Expansion on the Farm Land: The Case of Damot Gale Woreda, Wolayta Zone, Southern Ethiopia Yohanes Chinasho Data; Zerihun Kebebew; Tibebu Alemu Majority of the People in Ethiopia rely on eucalyptus for socioeconomic benefits. As a result, the conversion of farmlands into eucalyptus woodlots has sparked significantly. There has been still a concern on eucalyptus expansion on charge . The study aimed at assessing the impact of eucalyptus plantation expansion on the farm land in the case of Damot Gale woreda, Wolaita zone, southern Ethiopia. Spatial data were collected different years' (1993,2003,2013 and 2023) satellite imageries were used to effectively analyze LULC changes patch to compute the trend of eucalyptus expansion. Around 165 sample points were collected using handheld GPS Garmin 72 to check the image classification accuracy. Socio economic data were collected using semi structured questionnaires, focus group discussions and key informant interviews. The Socio economic results showed that about 61.3% (114) of the households were converted their farm lands into eucalyptus plantation .The reasons for the expansion of eucalyptus plantations include economic influence the benefits of eucalyptus, road construction, and urban expansion, as stated by respondents, key informants, and focus group desiccation. From the spatial data analysis result, substantial LULC changes have been observed in the last three decades. The result show that farmland decreased by 19.96% from the year 1993 to 2023, The trend of eucalyptus plantation expansion has increased from 257.67ha (9.07%) in 1993 to 1099.17ha in 2023 by 29.63 % of Farm land into Eucalyptus changed .Farmers plant eucalyptus in study areas on areas of farm land b y 122 farmers (65.59%), grazing land by 31 farmers (16.67%), on degraded land or the land that declines in productivity of cereal crops by 19 farmers (10.22%), and in bush land by 14 farmers (7.53%). This shows that communities are intensively converting their farmland to eucalyptus woodland and this creates a huge negative impact on farm land. These call an intervention and effective agricultural land use planning and management policies in accordance with eucalyptus plantation. 2025-04-27T00:00:00Z