Browsing by Author "Ndakidemi, Patrick"

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Accumulation and bioconcentration of heavy metals in two phases from agricultural soil to plants in Usangu agroecosystem-Tanzania
(Heliyon, 2021-07-07) Mng’ong’o, Marco; Munishi, Linus; Ndakidemi, Patrick; Blake, William; Comber, Sean; Hutchinson, Thomas
The build-up of heavy metals (HM) in agricultural soils accelerates the HM uptake by plants, which could potentially affect food quality and food safety. Here we studied the status and bioaccumulation of HM from soils to plant parts (roots, stem, and grains) in Usangu agro-ecosystem-Tanzania. In total 68 soil samples and 42 rice plant samples from six irrigation schemes were studied. The concentrations of cadmium-Cd, chromium-Cr, copper-Cu, lead-Pb, zinc-Zn, nickel-Ni, and iron-Fe were determined to estimate accumulation, distribution, bioconcentration. Total soil HM concentration in soil and plant samples was determined by acid digestion. The concentration of HM in soils samples (in mg/kg) were Cr (4.58–42.76), Co (1.486–6.12), Fe (3513.56–12593.99), Zn (7.89–29.17), Cd (0.008–0.073), Cu (0.84–9.25), Ni (0.92–7.98), and Pb (1.82–18.86). The total HM concentration in plant samples were (in mg/kg) were Cu (5.18–33.56), Zn (57.03–120.88), Fe (963.51–27918.95), Mn (613.15–2280.98), Cd (4.3–17.46), Pb (0.01–28.25), Cr (12.88–57.34) and Ni (9.65–103.33). The concentration of HM in soil and plant parts was observed to vary among locations where high concentrations of HM were detected in stems and roots compared to grains. The ratio HM in plants and soil samples (bioconcentration) was higher than one for some sites indicating higher HM uptakes by plants leading to possible health risk to soil invertebrates, animals, and humans. The bioconcentration factor varied among schemes, with the highest values at Igalako and Mahongole, which could be caused by artisanal gold mining and mining quarry existed in the area. Therefore, steps are needed to reverse the situation to balance the HM in agricultural soils and plant tissues to be within acceptable limits. Keywords
Agro-Morphological Exploration of Some Unexplored Wild Vigna Legumes for Domestication
(MDPI, 2020-01-13) Harouna, Difo Voukang; Venkataramana, Pavithravani; Matemu, Athanasia; Ndakidemi, Patrick
The domestication of novel or hitherto wild food crops is quickly becoming one of the most popular approaches in tackling the challenges associated with sustainable food crop production, especially in this era, where producing more food with fewer resources is the need of the hour. The crop breeding community is not yet completely unanimous regarding the importance of crop neo-domestication. However, exploring the unexplored, refining unrefined traits, cultivating the uncultivated, and popularizing the unpopular remain the most adequate steps proposed by most researchers to achieve the domestication of the undomesticated for food and nutrition security. Therefore, in the same line of thought, this paper explores the agro-morphological characteristics of some wild Vigna legumes from an inquisitive perspective to contribute to their domestication. One hundred and sixty accessions of wild Vigna legumes, obtained from gene banks, were planted, following the augmented block design layout of two agro-ecological zones of Tanzania, during the 2018 and 2019 main cropping seasons for agro-morphological investigations. The generalized linear model procedure (GLM PROC), two-way analysis of variance (two-way ANOVA), agglomerative hierarchical clustering (AHC) and principal component analysis (PCA) were used to analyze the accession, block and block vs. accession effects, as well as the accession × site and accession × season interaction grouping variations among accessions. The results showed that the wild species (Vigna racemosa; Vigna ambacensis; Vigna reticulata; and Vigna vexillata) present a considerable variety of qualitative traits that singularly exist in the three studied checks (cowpea, rice bean, and a landrace of Vigna vexillata). Of the 15 examined quantitative traits, only the days to flowering, pods per plant, hundred seed weight and yield were affected by the growing environment (accession × site effect), while only the number of flowers per raceme and the pods per plant were affected by the cropping season (accession × season effect). All the quantitative traits showed significant differences among accessions for each site and each season. The same result was observed among the checks, except for the seed size trait. The study finally revealed three groups, in a cluster analysis and 59.61% of the best variations among the traits and accessions in PCA. Indications as to the candidate accessions favorable for domestication were also revealed. Such key preliminary information could be of the utmost importance for the domestication, breeding, and improvement of these species, since it also determines their future existence—that is, so long as biodiversity conservation continues to be a challenging concern for humanity
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
Antimicrobial Activity of Tetradenia riparia (Hochst.) Lamiaceae, a Medicinal Plant from Tanzania
(European Journal of Medicinal Plants, 2014-08-08) Njau, Efrem-Fred; Alcorn, Jane-Mary; Buza, Joram; Chirino-Trejo, Manuel; Ndakidemi, Patrick
Aims: To evaluate the antibacterial activity of Tetradenia riparia crude extracts against Escherichia coli, Staphylococcus aureus and Enterococcuss faecalis. The phytochemicals that are responsible for the bioactivity were also screened. Study Design: In vitro assay of antibacterial properties. Place and Duration of Study: Samples were collected from Njari village at Uru North in Moshi district located in north eastern Tanzania. Extraction and phytochemical analyses were conducted at the College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, Canada. Antimicrobial assay was carried out at Department of Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Canada between March 2013 and August 2013. Methodology: Agar well diffusion test was used to determine antimicrobial activity of the plant extracts. Ethanol, methanol, hexane and distilled water were used as extracting solvents. These extracting solvents were removed by vacuo evaporator. The resulting concentrated gummy-like materials were dissolved in Dimethysulfoxide (10% DMSO). Chemical tests were used to determine the group of phytochemicals present in the sample extracts. Results: Sensitivity testing results indicated that S. aureus was found to be more sensitive than E. coli and E. faecalis. Tetradenia riparia methanolic extracts from the root were the most active with zone of inhibition values of 29.33±0.88mm, 21.33±0.33mm and 20.0±1.0mm in diameter against S. aureus, E. faecalis and E. coli respectively. The relative inhibitory zone diameter (RIZD) was calculated. The highest percentage values of relative inhibition zone diameter of 84±5.06% (S. aureus) and 76±6.86% (E. coli) were demonstrated by T. riparia root methanolic extracts. However, T. riparia leaf and root extracts using hexane as well as leaf extracts using water did not show any antibacterial activity against E. faecalis. Root methanolic and ethanolic extracts demonstrated the minimum inhibitory concentrations ranging from 1.25mg/ml to 5.00mg/ml. Phytochemical screening of crude extracts from leaf and root of T. riparia revealed the presence of alkaloids, flavonoids, phenolics, saponins, tannins and sterols. Conclusion: The study findings suggest likelihood of designing and developing potentially active antibacterial drug from T. riparia. Further studies should concentrate on the investigations of not only leaf but also the root part of the plant.
Antimicrobial and Antioxidant Activity of Crude Extracts of Rauvolfia caffra var. caffra (Apocynaceae) From Tanzania
(Canadian Center of Science and Education, 2014-09-24) Njau, Efrem-Fred; Alcorn, Jane; Ndakidemi, Patrick; Chirino-Trejo, Manuel; Buza, Joram
As part of an effort to search for extracts and compounds with new antimicrobial efficacy to fight against bacterial resistance, the antibacterial activity of Rauvolfia caffra var. caffra (Sond.), a plant of family Apocynaceae used in Traditional Medicine in Tanzania, was investigated. Ethanol, methanol and water extracts from leaf, stem and root barks were tested against three species of bacteria namely Escherichia coli (ATCC 25922) (Gram -ve), Staphylococcus aureus (ATCC 25923) (Gram +ve) and Enterococcus faecalis (ATCC 51299) (Gram +ve) using Agar-well diffusion assay method and minimum inhibitory concentration on Mueller-Hinton Agar plates. The extracting solvents were removed by vacuo evaporator to obtain gummy-like extracts. This was then dissolved in dimethylsulfoxide (10% DMSO). The DMSO without plant extracts was used as a negative control whereas Gentamicin® as the standard antibiotic was used as a positive control. The Zone of Inhibition (ZOI) measured in mm and Relative Inhibitory Zone Diameter (RIZD) was calculated. Results showed that R. caffra exhibited antimicrobial inhibitory activity at a range of 1.25 to 5.0 mg/ml with activity most prominent with methanol extract (ZOI of 28.33± 0.33 mm and RIZD of 95% for S. aureus; and ZOI of 26.66 ± 0.33 mm for E.coli and 19.0 ± 0.57 mm for E. faecalis at P< 0.05). To characterize further, the alkaloid from the root bark was extracted according to the standard procedure. The antioxidant activity of the alkaloids and ethanolic extracts was determined using 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and reducing capacity assays. The results indicated that alkaloid fraction of the root and 80% ethanolic extracts of stem bark exhibited high antioxidant activity. The phytochemical analysis indicated that R. caffra is rich in alkaloids, anthraquinones, anthocyanoides, flavonoids, saponins, tannis and reducing sugars. This study provides supportive evidence that methanol and ethanol extracts of R. caffra can be used as herbal medicine in control of E.coli, S. aureus and E. faecalis.
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.
Assessing Vulnerability of Food Availability to Climate Change in Hai District, Kilimanjaro Region, Tanzania
(Scientific Research Publishing Inc, 2014-09) Lema, Anza; Munishi, Linus; Ndakidemi, Patrick
Climate change has a large effect on agriculture sector and, consequently, on the food available for residents of Hai District and other regions of Tanzania. Based on four decades of climate data, this study assessed the impacts of climate change and its potential vulnerability on food availability in Hai District, Kilimanjaro region. The results from this study suggest an association between food crop production and variation in climate (temperature and rainfall) in Hai District. Considering the aspect of rainfall and temperature, we demonstrate that rainfall and temperature have significant relationship with maize and bean outputs. The rainfall had a strong positive association with maize and beans production and whereas temperature had inverse relationship with maize and beans yields. With the annual loss $0.04 million and $0.01 million per year from cattle and goats/sheep respectively and the additional annual loss of $29 million and $10.8 million from maize and bean crops respectively in Hai District during years of severe and prolonged droughts, our study highlighted how severe droughts can dramatically affect agriculture production and food security in the area. To mitigate climate change and provide effective adaptation measures, it is imperative to develop a broader research framework, which integrates bio-physical and socioeconomic aspects of food systems which addresses its vulnerability and thereby improve food security.
Assessment of arsenic status and distribution in Usangu agro-ecosystem-Tanzania.
(Elsevier Ltd., 2021-06-09) Mng'ong'o, Marco; Comber, Sean; Munishi, Linus; Blake, William; Ndakidemi, Patrick; Hutchinson, Thomas H
This study was conducted to assess arsenic (As) status and distribution in Usangu agroecosystem-Tanzania, including three land use. About 198 soil samples were collected in ten irrigation schemes in three land uses. Total and bioavailable As were determined by acid digestion (Aqua regia (AQ)) and Mehlich 3 method (M3) to estimate status, distribution and bioavailability. Arsenic concentration were variable among land use and irrigation schemes where total arsenic ranged 567.74-2909.84 μg/kg and bioavailable As ranged 26.17-712.37 μg/kg. About 12-16% of total arsenic were available for plant uptake. Approximately 86.53% of studied agricultural soils had total As concentration above Tanzania maximum allowable limit. Bioavailable As were lower compared to total As and were within the acceptable threshold. Total arsenic concentration were variable among schemes and higher values were observed in schemes which are highly intensified and mechanized. Thus, this study provides essential site specific preliminary baseline information for As status and distribution in agricultural soils to initiate monitoring and management strategies for increased land productivity and environmental safety.
Assessment of Farmers’ Indigenous Knowledge and Preferences: A Tool for Sustainable Lablab Bean (Lablab purpureus. L. Sweet) Improvement and Utilization in Northern Tanzania
(Journal of Advances in Biology & Biotechnology, 2019-03-27) Chawe, Kissa; Venkataramana, Pavithravani; Ndakidemi, Patrick
Participatory farmers’ selection of preferred lablab bean (Lablab purpureus L. Sweet) was conducted in Moshi Rural, Kilimanjaro in northern Tanzania to identify farmers preferred traits and accessions. An experimental plot was laid down in augmented block design where a total of 41 accessions including the local check (Katumani) and improved variety (HA4) were sown in three blocks at the spacing of 75 cm x 40 cm. Semi-structured questionnaire and checklists were prepared to gather the farmers’ preferences and knowledge as well as factors for lablab crop abandonment. The factors for crop abandonment identified were unavailability of quality and improved varieties, low yield, the high cost of agro-chemicals, the presence of diseases and insect pests. In this study, farmers’ selection criteria of the accessions were resistance to diseases and insect pest, the number of pods per plant, early maturity, high yielding capacity, seed colourand size. The results showed that accessions D163 scored higher votes followed by D137, D88, D27, D85, D155, D7, D159, and D151 while the least preferred accession was D140 with Garrets’ mean score of 50.11, 50.06, 50.05, 50.02, 50.00, 49.88, 49.77, 49.59, 49.56 and 49.52, respectively. Farmers’ ranked traits to be incorporated for future bean breeding in order of importance as; high yielding, better taste, earliness and short cooking time. Therefore, successful selection of germplasm through participatory research can raise awareness, adoption, and utilization of the lablab crop which change the portfolio of varieties available in the area and open the new door for plant breeders.
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.
Assessment of the soil suitability for soybean growth and the prospect biofertilizers use in selected areas of Tanzania
(Maximum Academic Press, 2023-10-19) Nakei, Monica; Venkataramana, Pavithravani; Ndakidemi, Patrick
The rapidly increasing global human population threatens the availability of safe and nutritious food. Among others, soil fertility degradation, insufficient use of proper fertilizers and scanty soil characterizations have major contributions in lowering the productivity of crops. To ensure the use of sufficient proper fertilizers for optimum crop productivity, it is important to evaluate the fertility status of soil which is a vital tool in deciding the type and the amount of fertilizer to be supplemented. This study aimed at evaluating soil fertility in the soybean growing and the non growing areas of Tanzania and to assess their suitability for growing the soybean crop as well as prospective use of rhizobia biofertilizers through the assessment of nodule formation in non-inoculated soybean plants grown in different farmers' fields. A total of 81 soil samples including those in soybean growing and non growing areas of Tanzania, were evaluated in terms of their fertility status through different physico-chemical parameters. From each field, three healthy plants with intense green leaves were selected for nodule counting. The study indicated that, most of the soils (85%) have medium acidic to neutral soil pH with 58% having sufficient organic carbon and 78% at risk of nitrogen deficiency. Soil pH, total N and OC had significant (p < 0.05) correlations (r) of 0.14, −0.22 and −0.27 with nodule number. The higher number of nodules were in medium acidic to neutral soils, with the highest number, 8.82 in neutral pH soils, indicating the favorability of the particular pH ranges for rhizobia activities. The results of this study suggest that most of the soils are suitable for the production of soybean and the use of rhizobia inoculants.
Assessment of Water Absorption Capacity and Cooking Time of Wild Under-Exploited Vigna Species towards their Domestication
(MDPI, 2019-09-04) Harouna, Difo Voukang; Venkataramana, Pavithravani; Matemu, Athanasia; Ndakidemi, Patrick
Some phenotypic traits from wild legumes are relatively less examined and exploited towards their domestication and improvement. Cooking time for instance, is one of the most central factors that direct a consumer’s choice for a food legume. However, such characters, together with seed water absorption capacity are less examined by scientists, especially in wild legumes. Therefore, this study explores the cooking time and the water absorption capacity upon soaking on 84 accessions of wild Vigna legumes and establishes a relationship between their cooking time and water absorbed during soaking for the very first time. The accessions were grown in two agro-ecological zones and used in this study. The Mattson cooker apparatus was used to determine the cooking time of each accession and 24 h soaking was performed to evaluate water absorbed by each accession. The two-way analysis of variance revealed that there is no interaction between the water absorption capacity and cooking time of the wild Vigna accessions with their locations or growing environments. The study revealed that there is no environment × genotype interaction with respect to cooking time and water absorption capacity as phenotypic traits while genotype interactions were noted for both traits within location studied. Furthermore, 11 wild genotypes of Vigna accessions showed no interaction between the cooking time and the water absorption capacity when tested. However, a strong negative correlation was observed in some of the wild Vigna species which present phenotypic similarities and clusters with domesticated varieties. The study could also help to speculate on some candidates for domestication among the wild Vigna species. Such key preliminary information could be of vital consideration in breeding, improvement, and domestication of wild Vigna legumes to make them useful for human benefit as far as cooking time is concerned.
Balancing Bees and Livestock: Pastoralist Knowledge, Perceptions and Implications for Pollinator Conservation in Rangelands, Northern Tanzania
(SAGE journal, 2021-01-01) Mpondo, Faith; Ndakidemi, Patrick; Treydte, Anna
Insect pollinators provide numerous ecosystem services that support other living organisms. While pollinators play a large role in cropping systems, little is known about their presence and function in rangeland ecosystems, which have recently become fragmented and overexploited at an extraordinary rate. We assessed local Maasai knowledge on insect pollinators and how pollinators affect livelihood diversification in Simanjiro rangelands, Tanzania. Through questionnaires, key informant interviews, focus group discussions, and field observations, we found varied insect knowledge among Maasai herders. Lasioglossum of sub genus Ipomalictus and Syriphidae were the least commonly recognized pollinators as only 24%, and 7% of participants could identify them, respectively. Responses varied significantly between men and women (F ¼ 7.397, p ¼.007). Commiphora africana, Acacia mellifera and Albizia anthelmintica were noted as most important bee forage plants while observations showed Aspilia mossambicensis, Justicia debile and Acacia tortilis. Most (77%) of Maasai herders showed limited ability to link pollinators and rangeland wellbeing. Beekeeping contributed to livelihood diversification for 61% of respondents, with women participating more frequently than men (v2 ¼ 46.962, p ¼.0001). Beekeeping was positively influenced by education level (R ¼ .421, p <.0001) and occupation (R ¼ .194, p ¼.009). Pollinator declines were attributed to climate change (47%), agriculture (37%), and habitat destruction (8%). We conclude that Maasai have limited knowledge of common pollinator groups and their roles. Community outreach and training should bridge the knowledge gap in pastoralist communities to fully realize pollinator benefits and highlight the importance of rangeland health.
Better nitrogen fertilizer management improved Mchare banana productivity and profitability in northern highlands, Tanzania
(MDPI, 2023-05-20) Meya, Akida; Swennen, Rony; Ndakidemi, Patrick; Mtei, Kelvin; Merckx, Roel
Declining land productivity is a major problem constraining banana (Musa spp.) production in Tanzania. Banana fruit yield consequently reaches only 15% of the potential, primarily due to inadequate soil nutrient replenishment. Improving farmers’ soil nutrient replenishment strategy in banana home gardens, which relies on applications of cattle manure only, by mixing with inorganic fertilizer resources can increase land productivity and can improve the overall profitability of banana production in the country. Experiments were conducted at Tarakea, Lyamungo, and Tengeru to determine the effects of organic fertilizer resources (animal manure and crop residue) and their combination with inorganic fertilizer resources on the productivity and profitability of Mchare banana production. Banana fruit yield differed significantly among the experimental sites, with drier areas of Tengeru recording, on average, 19.6 t ha−1 year−1 , while the more humid areas of Lyamungo recorded, on average, 39.3 ha−1 year−1 . Mchare banana plants grown under sole inorganic fertilizer produced significantly low yields (33.0 t ha−1 year−1 ) compared with those fertilized with cattle manure only, which lifted the yields to 38.8 t ha−1 year−1 , but the latter required more labor input. Soil nitrogen (N) fertilization via cattle manure + mineral fertilizer gave the highest average banana fruit yield (43.0 t ha−1 year−1 ) across the sites, and reduced fertilization costs by 32%. Subsequently, this integrated fertilization technique generated the highest average net benefits in all sites and both cropping cycles. Thus, the findings of this study form a basis to improve land productivity and profitability in banana-based home gardens in the study area by directing more labor input to good soil N management
Biomonitoring of Acetylcholinesterase (AChE) Activity among Smallholder Horticultural Farmers Occupationally Exposed to Mixtures of Pesticides in Tanzania
(Hindawi, 2019-09-11) Kapeleka, Jones; Sauli, Elingarami; Sadik, Omowunmi; Ndakidemi, Patrick
Biomonitoring of pesticides exposure has currently become a matter of great public concern due to the potential health effects of pesticides. ,is study assessed levels of acetylcholinesterase (AChE) inhibition and associated health effects in uncontrolled smallholder farming systems in rural Tanzania. A cross-sectional study was conducted of 90 exposed farmers and 61 nonexposed controls from horticultural zones. A structured questionnaire was administered, and a capillary blood sample of 10 μl was used to measure AChE activity using an Erythrocyte Acetylcholinesterase Test Mate Photometric Analyzer kit (Model 400). A multiple logistic regression model was used to investigate determinants of pesticide exposure. ,e study revealed that smallholder farmers are occupationally exposed to pesticides. Exposed farmers had significantly lower AChE levels. ,e use of personal protective equipment (PPE) did not significantly reduce the likelihood of AChE inhibition. Women, younger and older farmers, and underweight, overweight, and obese farmers were at increased risk of AChE inhibition. Increase in age (10 years) increased likelihood of AChE inhibition by 6.7%, while decrease in BMI increased likelihood of AChE inhibition by 86.7% while increased pesticides contact hours increased risk of having lower AChE at about 3 times. ,e number of exposure symptoms (14.10 ± 7.70) was higher in exposed farmers than unexposed. Self-reported symptoms are confirmed to correlate to lower AChE. Prevalence of tiredness (71.6% against 15.5%), fatigue (64.8% against 27.6%), soreness in joints (59.1% against 20.7%), thirst (52.3% against 12.1%), skin irritation (52.1% against 17.2%), salivation and abdominal pain (50% against 8.6% and 31.0%, respectively), muscle weakness (47.7% against 24.1%), and memory loss (47.7% against and 29.3%) differed significantly between exposed and control. ,is study provides useful information regarding the level of occupational and environmental exposure to pesticides in smallholder horticultural production systems. Pesticides use needs to be controlled at farm level by developing pesticides monitoring and surveillance systems.
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.
Biopesticide efficacy of four plant essential oils against papaya mealybug, Paracoccus marginatus Williams and Granara de Willink (Hemiptera: Pseudococcidae)
(Heliyon, 2023-03-01) Mwanauta, Regina; Ndakidemi, Patrick; Venkataramana, Pavithravani
Worldwide, P. marginatus causes 75% of estimated economic loss in papaya farming, with an increase in production costs. The extract of plant essential oils (PEO) has the potential to control P. marginatus by degrading its wax coatings to death; however, it is less studied in the East African agroecosystem. Therefore, this study was conducted to evaluate the efficacy of four PEO from (neem, citrus, garlic, and castor) against P. marginatus at different concentrations (0.5%, 1%, and 1.5%) with and without 0.2% adjuvants separately as a biopesticide. The experiment was con ducted in a completely randomized design with four replications per treatment concentration. The papaya seeds (Carina variety) were used in the experiment. After 3 weeks from transplanting, 50 P. marginatus specimens were inoculated in each plant. Before treatment application, insect abundance, leaf curling, yellowing, and soot mold were assessed. Then, 24 h, 48 h, and 72 h after biopesticide application, insect mortality was assessed. The results showed a significant difference (p = 0.001) for all assessment intervals in PEOs. However, for the PEOs in combination with the adjuvants, the results were significantly different (p = 0.001) only at 24 h. It was found that among the biopesticides, neem oil (1.5%) + isopropyl alcohol was highly effective (95.5%) after 72 h followed by (Imidacloprid (91%), citrus oil 1.5% (90.7%) and neem oil (1.5%) + paraffin oil (81.0%). But also, there were significant differences among treatments on leaf curling, yellowing, and soot mold reduction in papaya plants 21 days after spray. We conclude that neem oil (1.5%) + 0.2% isopropyl alcohol, neem oil (1.5%) + paraffin oil, and citrus oil (1.5%) significantly controlled P. marginatus. Thus, we recommend adopting these formulations for papaya farmers to control P. marginatus in their farms; however, simple formulations which can be easily accessed by smallholder farmers are essential.
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.