Browsing by Author "Mbega, Ernest"

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A Study on Phytochemical and Nutrient Profile of Six Inedible Seaweed Species Found on the Coasts of Tanzania
(John Wiley & Sons Lt, 2025-08-29) Manga, Shengelo; Msuya, Flower; Mbega, Ernest; Moirana, Ruth
Coastal accumulation of inedible seaweeds generates substantial biomass that remains largely underutilized despite its agronomic potential. Tis study characterized six inedible seaweed species (Sargassum spp., Ulva spp., Enteromorpha spp., Hypnea spp., Padina spp., and Laurencia spp.) collected from the Tanzanian coastline to evaluate their suitability as inputs for organic fertilizer production. Samples were analyzed for pH, electrical conductivity, organic carbon, ash content, macro- and micronutrients, and phytohormones. Ulva spp. exhibited the highest organic carbon (24.1%), indole-3-acetic acid (6.29 ± 0.53 mg/kg), and naph- thaleneacetic acid (7 ± 0.50 mg/kg). Sargassum spp. exhibited the highest potassium (78,667 mg/kg), gibberellic acid (14.78 ± 0.70 mg/kg), and kinetin (20.82 ± 6.12 mg/kg) levels, indicating its potential value in promoting shoot growth. Padina spp. were richest in calcium (218,567 mg/kg) and magnesium (17,350 mg/kg). Enteromorpha spp. showed substantial organic carbon (22.53%) and high calcium (190,967 mg/kg). Hypnea spp. had the highest phosphorus content (1697 mg/kg) and exceptionally high sodium contents (52,933 mg/kg), while Laurencia spp. had higher iron contents (5373 mg/kg) and alkaline pH (7.88). Tese fndings confrm that underutilized coastal seaweeds are valuable sources of nutrients and plant hormones and can be converted into organic fertilizers to restore soil fertility and support sustainable agriculture.
Activity of ethanolic extracts of spices grown in Tanzania against important fungal pathogens and early blight of tomato
(Bulgarian Journal of Agricultural Science, 2021-12) Lengai, Geraldin; Mbega, Ernest; Muthomi, James
The nutritional and economic value of tomato is universally recognized yet its production in many regions is still low due to, among other reasons, fungal diseases. Farmers have desperately relied on synthetic chemical pesticides to manage the dis- eases but the chemicals, in spite of their efficacy, are associated with residual detrimental effects on human health and environ- ment. The objective of this study was to evaluate the antifungal activity of selected spices against important fungal pathogens of tomato. Bioactive compounds from seven spices namely clove, black pepper, turmeric, ginger, lemongrass, cinnamon and cardamom powders were extracted in ethanol and tested for antifungal activity against Alternaria solani, Fusarium oxysporum f. sp lycopersici and Pythium sp. in poisoned food bioassay. The most active spice extracts were further tested for efficacy against early blight of tomato under field conditions. All extracts were significantly active against the tested fungal pathogens by about 85%. Clove extract was the most active against all the pathogens inhibiting their growth 100%. Ginger, black pepper and turmeric extracts inhibited growth of all the pathogens by between 74-80%. Lemongrass extract was the least active with an antifungal activity of about 49%. Under field conditions, clove remained active in reducing early blight disease load by about 36% compared to the negative control. The antifungal activity demonstrated by the spice extracts is an indication that they could be relied upon for disease control and this study recommends their consideration, especially clove, for formulation into a botanical fungicide for management of early blight of tomato.
Advancement and practical applications of rhizobacterial biofertilizers for sustainable crop production in sub-Saharan Africa
(BioMed Central, 2021-12-13) Aloo, Becky; Mbega, Ernest; Tumuhairwe, John; Makumba, Billy
Agricultural intensification continues in Africa in attempts to meet the rising food demands of the equally rising population. However, most arable lands in the region are characterized by nutrient deficiency and over-reliance on synthetic fertilizers which consequently contributes to increased production costs, environmental pollution, and global warming. Decades of research on plant–rhizobacterial interactions have led to the formulation and commer- cialization of rhizobacterial biofertilizers globally for sustainable soil and crop health. Nevertheless, this promising technology has not received much attention in Africa and remains largely unexplored due to several constraints. This article discusses the practical applications of rhizobacterial biofertilizers for sustainable crop production in sub-Saha- ran Africa. The challenges of soil infertility and the use of conventional synthetic fertilizers in crop production in Africa are critically evaluated. An overview of the potential of rhizobacteria as biofertilizers and alternatives to synthetic fertilizers for soil fertility and crop productivity in the continent is also provided. The advantages that these biofertiliz- ers present over their synthetic counterparts and the status of their commercialization in the African region are also assessed. Finally, the constraints facing their formulation, commercialization, and utilization and the prospects of this promising technology in the region are deliberated upon. Such knowledge is valuable towards the full exploitation and adoption of this technology for sustainable agriculture for Africa’s food security.
Alectra vogelii, a Threat to Bambara Groundnut Production in Singida and Dodoma Regions, Tanzania
(Advances in Research, 2016-07-07) Mbega, Ernest; Massawe, Cornel; Mbwaga, Ambonesigwe
Aims: To document the occurrence and effect of Alectra vogelii on bambara groundnut yield in Tanzania. Place and Duration of Study: Singida and Dodoma regions, Tanzania between 4th to 20th April 2014. Methodology: The number of A. vogelii and of bambara groundnut plants per 2 m x 2 m quadrant in triplicates was counted per farm from nine different villages. The A. vogelii infestation was scored as 0 = no infestation, 1 = 1-5 (less severe), 2 = 6 – 10 (severe) and 3 = > 10 (very severe). The bambara groundnut yield loss was determined as (C-A)/ C x 100% or (C-B)/C X 100%, where C = Number of pegs in a non-infested plant, A =Number of pegs in a wilted A. vogelii- infested plants and B = Number of pegs in yellowing or stunted- A. vogelii infested plants Results: The average number of A. vogelii was 55 plants infesting about 26 plants per quadrant. This number scored 3 (very severe) in a 0-3 scale. The highest number of pegs (90, 75 and 68) per plant was recorded in the non- infected bambara groundnut plants in Iramba, Dodoma urban and Ikungi Districts, respectively, while smaller number or no pegs was recorded in yellowing-A. vogelii infected or wilted-A. vogelii infected plants translating to a yield loss of 97.3–100%. Conclusion: A. vogelii is a threat to bambara ground nut production in Tanzania. Yield losses of up to 100% have been recorded and this can affect growers who depend on the crop for their protein source. As no report from the literature showing the occurrence of A. vogelii in bambara groundnut in the country, we document its first report and effect on the yield of the crop in Tanzania. Future studies to determine distribution of A. vogelii in other bambara groundnut-growing areas are needed.
AMMI and GGE biplot analysis of maize genotypes for seed yield across different maize growing location in Tanzania
(Cogent, 2024-12-18) Mwendo, Marco; Mbega, Ernest; Ndunguru, Joseph; Philipo, Mashamba
Twenty maize genotypes including breeding lines along with improved local released varieties were assessed for grain yield and yield component stability under three different maize growing agro-ecological zones from January to August 2023. A randomized complete block design (RCBD) with three replication was employed. additive main effects and multiplicative interaction (AMMI) and genotype-by-environment interaction (GGE) analysis was utilized to study the genotype and environment (GE) interactions. The combined analysis of variance showed a significant difference (p ≤ 0.001) in grain yield traits between maize genotypes, environments, interactions and IPC components. The average mean grain yield ranged from 3244 to 5103 kg/ha with a grand mean of 4111 kg/ha The maximum and minimum grain yield was 12325.93 kg/ha (G4) and 1159.68 kg/ha (G9) respectively. The biplot results showed genotype G20, G3, G1, G17 and G15 demonstrated consistently high stable grain yield performance. Genotypes G14, G19 and G4 had high yields, but were unstable as they were far from the IPC1 zero line. Multi-trait stability value indicated that the best genotypes in performance for all traits were G5, G17 and G19. AMMI analysis revealed that the environment at Kibaigwa and NM-AIST was the most ideal environment for seed yield traits. Based on the consistently high and stable grain yield performance, along with other superior grain qualities and plant characteristics, genotypes G5 and G17 were selected and recommended to be advanced and released as new commercial maize varieties in Tanzania for wider cultivation by farmers together with G19, a commercially released variety in Tanzania.
Antifungal Activities of Some Medicinal Plants Against Colletotrichum lindemuthianum, the Causal Pathogen of Bean Anthracnose, and their Effect on Seed Germination and Seedling Performance
(Centre for Advancement of Applied Sciences, 2022-12-12) Christopher, Faustine; Ndakidemi, Patrick; Nyalala, Samuel; Mbega, Ernest
This study evaluated the in vitro potency of Plectranthus barbatus, Vernonia amygdalina, Conyza bonariensis, Leonotis nepetifolia, and Lantana camara extracts against Colletotrichum lindemuthianum, the causal pathogen of anthracnose in common bean (Phaseolus vulgaris), as well as assessed their effect on seed germination and seedling performance under greenhouse conditions. In vitro assessment of antifungal activities of extracts was carried out using the poisoned food technique. Ethyl acetate extract of C. bonariensis was found most effective against the pathogen and completely inhibited its growth at 5.0, 2.5, and 1.25 mg mL-1 while it showed 91.2% inhibition at 0.5 mg mL-1 level. This was followed by P. barbatus and L. nepetifolia which completely inhibited the growth at 5.0 and 2.5 mg mL-1 level. Methanolic extracts were also effective with highest inhibition observed for L. camara (85.1%) at 5.0 mg mL-1, followed by P. barbatus (84.7%) and L. nepetifolia (83.1%) at the same concentration. Similarly, the aqueous extracts showed remarkable inhibition at the highest concentrations tested. Aqueous extracts of L. nepetifolia, V. amygdalina, and C. bonariensis inflicted maximum inhibition at 5.0 mg mL-1 (75.0, 74.7, and 73.3%, respectively). Extracts had no adverse effect on seed germination and seedling performance, but the test fungicide reduced seed germination significantly (p < 0.001). Easy accessibility of the studied medicinal plants and their potential in managing bean anthracnose provides an opportunity to use such plant extracts as seed dressers to manage bean anthracnose in smallholder farmers in Tanzania.
Antifungal activity of Leonotis nepetifolia extracts against Colletotrichum species causing bean anthracnose and their phytochemical analysis using LC-MS
(Elsevier B.V., 2023-08-30) Christopher, Faustine; Ndakidemi, Patrick; Nyalala, Samuel; Mbega, Ernest
Bean anthracnose results in significant yield losses, and the present primary management strategy of using synthetic fungicides is hampered by a number of factors. This study assessed the antifungal effects of aqueous, methanolic, and ethyl acetate extracts of Leonotis nepetifolia (Lamiaceae) against Colletotrichum species that cause bean anthracnose. The poisoned food technique was used to evaluate extracts in-vitro, and trials were carried out on farmer's plots. On the other hand, phytochemical analysis was done using LC-MS. Results obtained in-vitro show that the ethyl acetate extract was the most effective since it completely inhibited mycelial development at concentrations of 5 mg/mL and 2.5 mg/mL. On the other hand, the aqueous and methanolic extracts exhibited a comparable inhibitory effect, and at the higher concentration (5.0 mg/mL), a remarkable percentage of inhibition of 73.3% and 83.1% was recorded. According to field trials, bean anthracnose incidence was low and there were fewer infected pods per plant in plots treated with L. nepetifolia extracts than in the negative control. In comparison to the negative control plots, extracts-treated plots had larger weights of 100 seeds but no discernible negative effect in seed germination. LC-MS analysis indicated the presence of Linoleoyl ethanolamide, Curcumol, Deguelin, 9,10-dihydroxy-12Z-octadecenoic acid, Naringenin-7-O-glucoside, and 9S-hydroxy-10e 12z 15z-octadecatrienoic acid in the ethyl acetate extract whereas 6-Methoxyluteolin, Genistein, 5,7,3,4-tetramethoxyisoflavone, and 3,4-Dihydroxymandelic acid were identified in the aqueous extract. Antifungal activity and the presence of bioactive components revealed by extracts in this study demonstrate the potential of L. nepetifolia as a source of botanical fungicide for the management of bean anthracnose.
Antifungal Effects against Phaeoisariopsis personata under Greenhouse Conditions and Phytochemical Analysis of Jatropha curcas Leaf Extracts
(International Journal of Agriculture and Biology, 2021-07-10) Francis, Magreth; Chacha, Musa; Ndakidemi, Patrick; Mbega, Ernest
The study was conducted to test the antifungal efficacy of J. curcas leaf extracts against Phaeoisariopsis personata (causal pathogen for groundnut late leaf spot disease) under in vivo conditions, and to identify important phytochemical constituents exhibiting antifungal properties. The results showed that the greatest reduction of late leaf spot disease incidence was achieved by all the Jatropha curcas leaf extracts at the highest concentration (0.5 mg mL-1 ) as 36.89, 36.59 and 24.67% for chloroform, ethyl acetate and methanolic extracts, respectively. Subsequently, J. curcas leaf extracts treatments enhanced the growth and yield of groundnut compared with the control (untreated). The antifungal effects of J. curcas were supported by the presence of phytochemical constituents identified by GC-MS. Hexadecane; n-hexadecanoic acid; phenol, 2, 4 bis (-dimethylethyl); phytol and hexadecanoic methyl ester were detected as major phytocompounds in J. curcas leaf extracts that were possibly responsible for the antifungal activity. © 2021 Friends Science Publishers
Assessing residue effects of tobacco nicotine on the yields, nutrient concentrations and nicotine uptake of a subsequent maize crop
(Elsevier, 2022-03-01) Lisuma, Jacob; Philip, Amon; Ndakidemi, Patrick; Mbega, Ernest
The residue effects of tobacco (Nicotiana tabacum L.) nicotine on the subsequent maize (Zea mays L.) crop cultivated in soils differing in texture has rarely been studied for over a decade. The present study was conducted on sandy soil of Tabora, and loamy sand soils of Urambo, and Sikonge sites in Tabora region of Tanzania, to assess the residue effects of tobacco nicotine on latter performance of a maize crop. The experiment was laid out in a complete randomized block design with three replications. During the first cropping season (2017–18), the treatments were composed of one unfertilized cultivated plot of tobacco as a control and a fertilized cultivated plot, where the seedlings of flue-cured tobacco variety K326 were transplanted. Two separate plots were kept fallow for planting sole maize (DKC-8053) under fertilized and unfertilized conditions without any nicotine residue during the succeeding second (2018–19) and third (2019–20) cropping seasons. Moreover, in the first cropping season, in one fertilized tobacco plot, tobacco stalks after reaping leaves were incorporated in soil for natural decomposition, while in the other fertilized tobacco plot, tobacco stalks were uprooted. In the second and third cropping seasons, the residue nicotine was measured in soils and found to range from 0.25 to 0.86 mg kg− 1 in both unfertilized and fertilized tobacco plots. The residue nicotine ranged from 0.92 to 1.05 mg kg− 1 in fertilized tobacco cultivated soils with tobacco stalks. Results showed that nicotine residue in soil decreased maize grain yield by 0.08 t ha− 1 . The decrease of maize grain yield was also attributed to inadequate P and K levels in soils planted with tobacco. Therefore, this study recommends the supplemental application of the limiting P and K nutrients when planting maize after tobacco.
Assessment of the Knowledge, Perceptions, and Reactions towards the African Apefly (Spalgis lemolea lemolea) in Tanzania
(MDPI, 2020-01-28) Nasari, Sayuni; Ndakidemi, Patrick; Mbega, Ernest
This paper reports on farmers’ knowledge, perceptions, and reactions towards the African apefly (Spalgis lemolea lemolea), which appeared to be associated with some vegetables in some locations in Tanzania. Information was obtained from a sample of 100 key respondents using a semi-structured questionnaire and from focus groups selected from key locations in five districts in the country with histories with the African apefly. Acute and sub-acute toxicity tests of the African apefly were performed on female Swiss hybrid mice (Mus musculus) to assess whether or not the African apefly was toxic to mammals. The mice were exposed to increasing apefly meal concentrations in acute and sub-acute tests, and signs of toxicity were observed for 14 and 28 days, respectively. Blood samples were collected by cardiac puncture for hematological and biochemical analysis. Gross and microscopic examinations of the internal organs were done. The survey results showed that 92.1% of the respondents perceived the African apefly as poisonous and had stopped consuming the vegetables associated with it. In the toxicity tests, however, no death or toxic signs were displayed, and there was no significant difference between the control and treated mice in weight, hematological parameters, and histo-pathological examination results. These findings strongly indicate that, despite the negative perception by farmers regarding the African apefly, it is not poisonous. However, further studies on how farmers can be trained to have a positive perception of the African apefly and how the insect can be conserved for further research regarding its role in Tanzania are recommended.
Biochar as a feed additive for improving the performance of farm animals
(Malaysian Journal of Sustainable Agriculture (MJSA), 2020-03-10) Lao, Emanuel; Mbega, Ernest
Biochar, also known as biomass-derived char or charcoal is a dark/black carbonaceous material generated from the pyrolysis process under temperature averagely 700 0C and low oxygen levels. Depending on the intended objectives and conditions of the pyrolysis, the biochar, syngas and bio-oils are the three primary products generated. The quality of biochar is a function of its primary biomass source, residence time and temperature during pyrolysis which in turn results in variations of its physicochemical characteristics such as porosity, carbon content, elemental composition, surface area, retention capacity, and overall applications. The physical and chemical activation techniques to produce the activated charcoal is often done to improve the effectiveness of these carbonaceous materials. The biochar has broadly been used globally in agro- environmental management including in livestock production. Its inclusion at 1 - 3 % of DM of animal feed rations have been studied to improve health conditions and performance of farm animals such as weight gain, immunity response, feed intake, feed conversion rates, carcass characteristics and overall quality of animal products. The mechanisms associated with the beneficial impacts rely on adsorption ability of these materials in detoxifying the mycotoxins in feed, regulating plant-produced toxins, having a high affinity to pollutants as well as improvement of the beneficial microbial populations in animals' gastrointestinal tract. However, the current literature indicates there is still a need for more investigation on the effectiveness of biochar in animal production due to either limited knowledge or contrasting findings reported. Also, there are imperative challenges which need to be addressed such as safety standards, specificity, potential contamination, affordability, and level of awareness by farmers who are end-users of biochar and its products.
Bionomics of the African Apefly (Spalgis lemolea) as A Potential Natural Enemy of the Papaya Mealybug (Paracoccus marginatus) in Tanzania
(MDPI, 2020-04-14) Nasari, Sayuni; Treydte, Anna; Ndakidemi, Patrick; Mbega, Ernest
The African apefly (Spalgis lemolea Druce) is a potential natural enemy of the papaya mealybug (Paracoccus marginatus Williams and Granara de Willink). We studied the life history of apeflies in the laboratory at a temperature of 25–27 °C and a relative humidity of 55%–65% under a 12 h photoperiod condition. The papaya mealybugs and apefly larvae were collected from papaya plants in Tengeru, Arusha, Tanzania. The papaya mealybugs were introduced and allowed to multiply on potted sprouting potato plants in screened cages. In order to study the life cycle and predation of apeflies, an apefly egg was placed on an open screen-covered petri dish containing a moist blotter paper and observed for larva emergence. After the apefly larva emergence, a mixture of mealybug eggs (up to 1500), nymphs (200–250) and adults (100–150) was introduced in the petri dish each day and the consumption rate by the apefly larvae was quantified until the larvae reached pupal stage. Then, the apefly adults were collected and put into cages 30 cm × 30 cm × 30 cm containing cotton wool soaked in water, for observation of pre-mating, mating, egg-laying and life span. Results indicate that the apefly completed its life cycle in 23 days. The mean development period of the eggs was four days and the development period for the larva, pre-pupa, and pupa was nine, one and ten days respectively. The adult apefly emerged after 9 days of the pupa stage with mean body lengths of 10.1 ± 0.4 mm and 11.0 ± 0.8 mm for the males and females, respectively. The female laid an average of 68 eggs in groups of two to seven at different sites after 4–5 days of emergence. In this study one apefly larva was capable of consuming about 1983 ± 117, 123 ± 6 and 80 ± 9 papaya mealybug eggs, nymphs and adults respectively during larval stage. These results reveal the predatory potential of the apefly in suppressing the population of papaya mealybugs under field conditions.
Biopesticides Potential to Protect Tomato (Solanum lycopersicum L.) Production from Early Blight Disease (Alternaria solani) and Leaf Miners (Tuta absoluta)
(preprint, 2025-01-03) Abel, Fikiri; Mkindi, Angela; Mbega, Ernest; Stevenson, Philip; Belmain, Steven; Venkataramana, Pavithravani
Early blight disease (Alternaria solani) and leaf miners (Tuta absoluta) pose significant biotic constraints to tomato production, causing 80 -100% yield loss. A study involving laboratory, screen house and field experiments evaluated the efficacy of plant and bio product pesticides including extracts of Azadirachta indica, Lantana camara , Cymbopogon citratus, Capsicum frutescens, Zingiber officinal and rabbit urine. We report significant inhibition of fungal mycelial growth ranging from 20% with a 5% rabbit urine to 98.25% by 10% hot pepper in the laboratory. Screen house trials showed a positive inhibitory effect of plant extracts on controlling leaf miners. The most effective extracts were 10% lantana (80%), 10% hot pepper (76.6%) and 10% ginger (72.6%).The most successful four extracts were used in field trials and resulted in an average 50% reduction in disease severity compared to the control. Also, 10% ginger, hot pepper (both 5% and 10%) and 10% lantana were effective in controlling Tuta absoluta and significantly reduced leaf damage. A cost benefit analysis showed that the 5% hot pepper treatment had the highest revenue benefit compared to the negative control and conventional tomato production methods. Further research is needed to integrate these biopesticides into crop management practices.
Biovar 2 of Ralstonia solanacearum Species Complex Causes Tomato Bacterial Wilt Disease in Tanzania
(Science Alert, 2020-03) Aloyce, Agatha; Ndakidemi, Patrick A.; Mbega, Ernest
Background and Objective: Bacterial wilt disease (BWD) caused by complex species of Ralstonia solanacearum (RSSC) has been categorized as one of the most significant plant diseases in the world. It is a serious problem of tomato and causes significant economic losses of tomato in Tanzania. The purpose of this study was to determine biovars of RSSC causing tomato BWD in Tanzania. Materials and Methods: Tomato stems showing typical symptoms of BWD were collected from main agro-ecological regions and were characterized by pathological and carbohydrate oxidation tests. The least significance difference (LSD) procedure was used for mean separation (p = 0.05) of disease incidence and severity. Results: A total of 29 out 40 RSSC isolates from infected tomato stems produced typical colonies of RSSC on triphenyl tetrazolium chloride medium out of which 19 (52%) were pathogenic on tomato variety Tanya. Carbohydrate oxidation test showed that most (90%) predominating isolates in main agro-ecological regions belong to biovar 3 while the rest (10%) belong to biovar 2 and prevail in the southern zone of Tanzania. This is the first report of prevalence of biovar 2 of Ralstonia in Tanzania and suggests a recent introduction of biovar 2 in tomato fields in Tanzania. Conclusion: Biovar 2 of RSSC is reported for the first time to cause tomato bacterial wilt disease in Tanzania. This alerts plant health regulators to embark on necessary phytosanitary measures to prevent further spread and/or introduction of the disease considering its quarantine status in different countries.
Botanical extracts control the fungal pathogen Colletotrichum boninense in smallholder production of common bean
(Springer link, 2024-04-11) Kushaha, Tamia; Mkindi, Angela; Mbega, Ernest; Stevenson, Philip; Belmain, Steven
Anthracnose caused by Colletotrichum spp. remains an intractable problem in the most common bean (Phaseolus vulgaris) production areas worldwide and can cause total yield loss. Many smallholder farmers are familiar with using botanical extracts to control insect pests; however, there is less familiarity with their use to control fungal diseases due to a lack of evidence. Here, we demonstrate that anthracnose could be controlled effectively by pesticidal plant species that are used for insect control. In laboratory trials, water extracts from 11 plant species could inhibit fungal growth (100%) and spore germination (75–100%) equally well to two commercially available fungicides, the syn- thetic Mancolaxyl and biofungicide Bioderma. In screenhouse trials, anthracnose disease was reduced by the extracts of three plant species. Moreover, bean crop growth in these botanical treatments did not differ significantly from that observed in the commercial fungicide treated plants. Field trials in a smallholder community reporting severe problems with anthracnose showed an effect similar to the screenhouse results. Field trials resulted in bean seed yields approximately 350 kg/ha higher in bean plants treated with Azadirachta indica and Lippia javanica at 10% w/v compared to the negative control untreated plants. In all trials, botanical extracts were as effective as commer- cially available fungicides, suggesting that these botanical extracts could provide dual-purpose pest and disease management for anthracnose and crop pest insects. The outcomes of this research show that prospects for using locally available resources to control anthracnose on common bean are credible and can be combined with control- ling insect pests.
Botanical Pesticides in Management of Common Bean Pests: Importance and Possibilities for Adoption by Small-scale Farmers in Africa
(Journal of Applied Life Sciences International, 2017-06-17) Karani, Ancila; Mbega, Ernest; Ndakidemi, Patrick
Botanical Pesticides (BPs) have been cited and are used as alternative to synthetic pesticides in agricultural systems worldwide. The BPs are believed to be safe to the environment and are used in pest control to avoid pesticidal pollution, which is a universal problem. In this review, authors provide comprehensive information on the use of BPs in management of common bean pests in Africa. This piece of literature is useful due to major negative side effects to the environment as well as human health arising from synthetic chemicals. It is due to this reason that the authors composed this review to provide insights on potentiality of the BPs in Africa. Generally, it is believed that majority of Africans, feel that BPs are their heritage, thus any technology derived from the BPs is likely to be highly adopted. This review highlights importance, preparation and different methods of applying the BPs so that farmers and other users of this document can easily understand quick methods of using BPs as alternative to synthetic pesticides in combating common bean pests in Africa. Furthermore, areas for future research have been highlighted to establish the need of moving the BPs industry forward for pest management in common bean and other crops in Africa.
Building sustainable societies through vertical soilless farming: A cost-effectiveness analysis on a small-scale non-greenhouse hydroponic system
(Elsevier, 2022-08) Gumisiriza, Margaret; Ndakidemi, Patrick; Nalunga, Asha; Mbega, Ernest
The growing rate of population and urbanization among African cities versus the reducing arable land has roused curiosity in soilless farming as an urban farming method to enhance food security and urban sustainability. This study investigated the economic viability of producing 60 heads of lettuce using a vertical non-circulating hydroponic system outside the green house as a low cost sustainable urban food production prospect for Africa. This was based on a hydroponic experiment set up in Uganda, East Africa 4 capital budgeting techniques were used for the analysis, that is; Net Present Value (NPV), Profitability index (PI), Internal Rate of Return (IRR) and Non-discounted Pay Back Period (NDPBP). A sensitivity and scenario analysis were adopted for risk analysis while regression analysis was considered for forecasting and modelling purposes. A discount rate of 10% was considered for the analysis based on the loan borrowing rate. The unit production cost equaled to 0.46$/head and sale price was estimated at 0.75/head. Initial costs deemed necessary for annual production were estimated at 171.1$. Results showed the following economic values: NPV (16.37$), IRR (12.57%), PI (1.1) and NDPBP (4,5) for annual crop production of 6 cycles. NPV was sensitive to changes in discount rate and unit price while revenue varied with a change in quantities sold and unit price as per the scenario analysis. A significant negative and positive linear relationship was found between unit price of lettuce versus quantity sold and revenue earned correspondingly. Adoption of vertical hydroponic lettuce production can be considered an equally cost-effective venture with substantial profits cetris paribus with the potential to increase food security and sustainability around urbanities. Further research needs to be done to assess the profitability of producing other vegetables using the same system across various seasons and cities.
Can soilless farming feed urban East Africa? An assessment of the benefits and challenges of hydroponics in Uganda and Tanzania
(Elsevier, 2022-01) Gumisiriza, Margaret; Kabirizi, Jolly; Mugerwa, Micheal; Ndakidemi, Patrick; Mbega, Ernest
East Africa has the potential to boost its urban food production through adoption of soilless farming techniques. The case study assessed the benefits and drawbacks allied with hydroponic vegetable farming among urban and peri‑urban farms in Northern Tanzania and Central Uganda. Snowball sampling was used to identify 150 vegetable farms/farmers through urban farmers’ groups and recommendations from the agricultural organizations from Uganda and Tanzania. Based on the complexity and distinctiveness of this farming system, only 51 individuals engaging in hydroponic vegetable production took part in responding to the semi-structured Google form questionnaire that was issued through social media platforms, face to face interviews and farm visits. Results from the study showed that hydroponics is a climate smart farming system (n = 13, 26%), produces high yields within limited space (n = 24, 48%), has no soil borne pests and diseases (n = 10, 20%) and gives the farmer the ability to control environmental conditions (n = 2, 4%). On the contrary, over 50% of the respondents reported high investment costs (n = 16, 31%) and lack of adequate knowledge on hydroponics (n = 11, 22%) as the main limitations of the technology. Based on farmers’ recommendations, hydroponics has potential to increase food security within urban areas if more efforts are put in sensitization about the farming system and research into ways to reduce the high costs associated with the technology.
Carrot-Weed: A Noxious Plant That Threatens Biodiversity in Africa
(Scientific Research Publishing, 2019-03-20) Mtenga, Neema; Tarimo, Thadeo; Ndakidemi, Patrick; Mbega, Ernest
Carrot-weed ( Parthenium hysterophorous L.) is a flowering plant of the As- teraceae family (tribe: Heliantheae). The weed became famous due to its no- torious invasive role in the environment and agricultural fields. The plant has arisen as the seventh most disturbing weed globally. In Africa, the weed is spreading very fast and information on its biology, impact, and management is scarce. Therefore, this review provides general information about the carrot weed’s current distribution status and its impact on agricultural crops, ani- mals and human health in Africa . The review also highlights areas for re- search in managing this noxious weed in the African habitats.
Characterization and detection of maize-associated pteridovirus (MaPV), infecting maize (Zea mays) in the Arusha region of Tanzania
(Springer Nature, 2019-03-01) Read, David; Featherston, Jonathan; Rees, David; Thompson, Genevieve; Roberts, Ronel; Flett, Bradley; Mashingaidze, Kingstone; Pietersen, Gerhard; Kiula, Barnabas; Kullaya, Alois; Mbega, Ernest
Maize lethal necrosis disease (MLND) is currently threatening maize production in a large area of East Africa. Synergistic infections of Maize chlorotic mottle virus (MCMV) and members of the Potyviridae family are known to elicit MLND. Metaviromics studies of plant viruses have allowed for the discovery of novel viral diversity, with a number of these viruses having recently been shown to co-occur with MCMV and Potyviruses. However, their contribution to the expression of disease symptoms still requires extensive research. In a survey for viruses associated with maize in Tanzania, 35 samples were sequenced using an RNA-tag-seq metaviromics approach. Bioinformatic analysis of assembled reads yielded two contigs (5.8 and 2.7 kbp) that shared sequence homology with RNA1 and RNA2 of the dsRNA Japanese holly fern mottle virus (JHFMoV) (genus: Pteridovirus) from a single sample collected in the Arusha region. RNA1 encodes for a polyprotein product containing putative viral methyltransferase, helicase and polymerase domains. RNA2 contains three open reading frames (ORFs), one of which encodes for a putative movement protein, while the remaining two encode for putative products with no known function. The tentative name Maize-associated pteridovirus (MaPV) has been proposed for the virus in this study.