Browsing by Author "Venkataramana, Pavithravani"

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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
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 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.
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.
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.
Breeding potential of lablab [Lablab purpureus (L.) Sweet]: a review on characterization and bruchid studies towards improved production and utilization in Africa
(Springer Nature Switzerland AG., 2021-09-21) Letting, Fanuel; Venkataramana, Pavithravani; Ndakidemi, Patrick
Lablab (Lablab purpureus) [Lablab purpureus (L.) Sweet] is termed a lost, underutilized and neglected crop in Africa. Despite the multipurpose use, production, consumption and research are still limited. Wide genetic diversity of lablab germplasm exists in Africa. Diversity studies provide significant information for subsequent research programs and improvement. The advent of genotyping and sequencing technologies has enabled the identification of unique and agronomically important traits. Application of next-generation sequencing on lablab as a pioneer orphan crop is currently underway. This has enabled description of the whole genome, generation of reference genome and resequencing that provide information on variation within the entire genome. Information from these technological advances helps in identifying potential traits for biotic and abiotic stress for further breeding programs. Storage pests specifically bruchids (Callosobruchus spp.), are considered a major obstacle in lablab production. Screening of available genotypes for bruchid resistance and studies on the physical and biochemical factors that confer resistance in lablab is required. Applying advanced technologies provides precise and reliable identification of the novel markers responsible for bruchid resistance allowing for introgression of important genes to breeding programs. This review provides a detailed analysis on the characterization of lablab and the information on bruchid resistance vital for breeding farmer-preferred varieties that possess agronomically beneficial traits. Concerted efforts and research on this neglected crop will enhance its production, utilization and consumption.
Breeding potential of lablab [Lablab purpureus (L.) Sweet]: a review on characterization and bruchid studies towards improved production and utilization in Africa
(Springer Netherlands, 2021-09-22) Letting, Fanuel; Venkataramana, Pavithravani; Ndakidemi, Patrick
Lablab (Lablab purpureus) [Lablab purpureus (L.) Sweet] is termed a lost, underutilized and neglected crop in Africa. Despite the multipurpose use, production, consumption and research are still limited. Wide genetic diversity of lablab germplasm exists in Africa. Diversity studies provide significant information for subsequent research programs and improvement. The advent of genotyping and sequencing technologies has enabled the identification of unique and agronomically important traits. Application of next-generation sequencing on lablab as a pioneer orphan crop is currently underway. This has enabled description of the whole genome, generation of reference genome and resequencing that provide information on variation within the entire genome. Information from these technological advances helps in identifying potential traits for biotic and abiotic stress for further breeding programs. Storage pests specifically bruchids (Callosobruchus spp.), are considered a major obstacle in lablab production. Screening of available genotypes for bruchid resistance and studies on the physical and biochemical factors that confer resistance in lablab is required. Applying advanced technologies provides precise and reliable identification of the novel markers responsible for bruchid resistance allowing for introgression of important genes to breeding programs. This review provides a detailed analysis on the characterization of lablab and the information on bruchid resistance vital for breeding farmer-preferred varieties that possess agronomically beneficial traits. Concerted efforts and research on this neglected crop will enhance its production, utilization and consumption.
Characterization of Farmer’s knowledge and management practices of papaya mealybug Paracoccus magnatus (Hemiptera: Pseudococcidae) in Tanzania
(Elsevier, 2022-02-22) Mwanauta, Regina; Ndakidemi, Patrick; Venkataramana, Pavithravani
Papaya mealybug (PMB) is a serious insect pest for papaya production in Sub-Saharan Africa, limiting production potential in farming communities. We did a household survey to evaluate the Characteristics of farmers' knowledge, challenges, and current (PMB) control practices in four papaya growing regions of Tanzania namely, Tanga, Dodoma, Pwani, and Katavi involving 100 papaya farmers. The study found that 96% of farmers reported PMB, as a major challenge in papaya production. Very few (0.8%) of the farmers were knowledgeable on insect pest identification. Chemical pesticides were the only option for PMB control, and 43.0% of farmers were able to access and apply. We also found that 36.4% of the farmers were aware of the adverse effects of chemical pesticides. Furthermore, the study observed that 0.3% of farmers use botanical pesticides. Additionally, the study observed that 44.1% of farmers use control measures against PMB, the remaining 55.9% did not practice any control measure, thus leading to low papaya yields observed in the study regions. Our findings provide insights to farmers into the use of plant-based pesticides, mainly plant essential oils, and its benefits that may promote farmers' attitudes towards increasing papaya yield and reducing chemical pesticide use to avoid pest resistance.
Characterization of phenotypic traits associated with anthracnose resistance in selected common bean (Phaseolus vulgaris L.) breeding material
(Elsevier Ltd, 2024-02-27) Kadege, Edith; Venkataramana, Pavithravani; Assefa, Teshale; Ndunguru, Joseph; Rubyogo, Jean Claude; Mbega, Ernest
Anthracnose caused by Colletotrichum lindemuthianum is the major common bean disease worldwide causing complete yield loss under favourable disease conditions. This study aimed to determine phenotypic traits associated with anthracnose resistance for future use in breeding programmes. Twenty-two common bean varieties (CBVs) were selected basing on susceptibility to anthracnose, advanced breeding lines, improved variety resembling advanced breeding lines and the farmer variety widely grown in Tanzania. Selected varieties were planted in anthracnose hotspot fields and the same CBVs were planted in a screen house to validate resistance to anthracnose. Anthracnose infection score, leaf length, leaf width, length of fifth internode, length of petiole, plant vigour, canopy height and canopy width were recorded. Data on number of plants emerging; days to flowering; days to maturity; plant stands at harvest; and grain yield were also collected and analysed using R software. Phenotypic traits evaluated differed significantly among genotypes, environment and genotype by environment interaction. Seventy-five percent of phenotypic traits evaluated were positively correlated to anthracnose resistance. Highly-strong correlations to anthracnose were observed on number of days to maturity, plant stands at harvest, plant vigour and grain yield. Leaf length, leaf width, length of fifth internode, length of petiole and number of stands emerging were strongly correlated to anthracnose resistance. Additive main effects and multiplicative interaction analysis (AMMI) revealed highest contribution of environment on anthracnose infection-58.9% and grain yield −84.9% compared to genotype effects on anthracnose infection −32.7% and grain yield-15.7%. Based on these results, four traits – plant vigour, number of days to maturity, number of plant stands at harvest and grain yield – are recommended for selecting anthracnose-resistant varieties. NUA 48, NUA 64 and RWR 2154 were superior varieties, resistant to anthracnose and high yielding, while Sweet Violet and VTT 923-23-10 were most stable varieties across environments. Further on-farm research is suggested to assess their performance and identify traits preferred by farmers.
Characterization of Provitamin A Status and Distribution in Commercial Grown Maize Varieties in Tanzania
(East African Journal of Science, Technology and Innovation, 2022-02-16) Msungu, Selly; Venkataramana, Pavithravani; Mushongi, Arnold
Provitamin A carotenoids are important as precursors for vitamin A, essential for stronger immune system and eyesight. Consumption of a plant-based diet rich in provitamin A such as provitamin A maize is an easy and affordable source of vitamin A. The majority of the commercially grown maize varieties in Tanzania are white whose provitamin A status is uncertain and undocumented. The existing current information suggests that white maize varieties have low provitamin A, an active form of vitamin A, thus putting maize consumers at risk of vitamin A deficiency (VAD). Characterization of provitamin A status in commercial maize varieties grown and consumed in Tanzania is important to provide baseline information required for vitamin A rich-maize improvement programs. Therefore, this study was conducted to map the status of provitamin A in commercial maize varieties to accrue the information needed to improve maize nutrition quality toward controlling VAD in the country. The study involved 14 maize varieties including commercial yellow and white pigmented maize from 3 regions of Tanzania. From maize samples, carotenoid extraction was conducted based on published protocol. The concentration of beta carotene (BC), beta-cryptoxanthin (BCX), alpha-carotene (AC) were determined by an ultraviolet spectrophotometer and provitamin A computed for the individual carotenoids components. The study found that the concentration of provitamin A and associated carotenoids significantly differed (p<0.001) among varieties studied. The mean concentration (in μg/g) for provitamin A and its components in range as provitamin A (2.64-6.50), BC (1.91-4.66), BCX (0.649-1.21), and AC (0.819-1.46). The concentrations of provitamin A in the studied maize varieties were below the recommended levels (15 μg/g). The low concentrations of provitamin A among commercial maize varieties signify the need for introgressions of provitamin A in the adapted maize genotypes for ensured intake of vitamin A.
Comparative Analysis of Phytocompound Variations in Leaves, Bark and Roots of Allspice (Pimenta Dioica) Collections in Tanzania
(AIJR, 2024-02-06) Lutege, Raymond; Venkataramana, Pavithravani; Ndunguru, Joseph
he efficient valorization of biomass for energy-derived biocrudes is essential for effective waste management. However, the production of biocrudes with high energy and reduced oxygen contents during the liquefaction process requires further insight. Therefore, the impact of reaction temperature, residence time, and ethanol: acetone on the energy compositions and bioproduct’s yield enhancement were investigated. The biocrudes obtained were characterized using elemental analysis, GC–MS, FTIR, GPC and TGA to understand the effects of process parameters on the biocrudes’ compositions. An improved HHV (38.18 MJ/kg) and lower O/C ratio (0.11) were obtained at 430 °C, 35 min and 50% ethanol with a significant improvement in the enhancement factor, deoxygenation, and percentage hydrogenation of 2.63, 36.88%, and 77.87%, respectively. The presence of ketones, hydrocarbons, phenolics and aromatics of 23.74, 4.28, 37.20 and 17.81% respectively indicate the potential of the obtained biocrude as renewable energy sources upon further upgrading.
Contribution of the Dolichos Lablab value chain to farmer's household livelihood assets in Tanzania
(Elsevier Inc., 2022-11-17) Minde, Josephine; Matemu, Athanasia; Venkataramana, Pavithravani
Lablab is a legume with multiple uses as food, feed, and organic fertilizer. However, it is underutilized, and its empirical contribution to farmers' livelihoods is limited. This study examined the Lablab value chain (LVC) relative to smallholder farmers' livelihood assets in Tanzania. Data on Lablab farming, its value chain, and its contribution to the farmers’ livelihood assets were collected from four districts of Tanzania known for Lablab production. The results showed that the LVC mapping comprised systems, actors, and interdependent activities, the key systems being input supply, tillage, intercropping, and marketing. Seed supply was through the recycling of the last harvest (48.8%), while intercropping (56.5%) and hand-hoeing (51.6%) were the primary cultivation systems, with farm gates and/or local markets serving as the marketing locations. The grown seeds were mainly black (62.3%) due to external marketability but were rarely eaten. Although farmers were the major chain actors, traders were highly active in the marketing segment, leaving farmers out of the bargain art protocol. Generally, Lablab production generated almost 90% of the farmers' revenue by multiple linear regression. Based on farmers' five asset categories, natural and human assets contributed 70% and 50% respectively, while there was less contribution from social, financial, and physical assets. The study recommends networking exposure to reliable marketplaces with good prices, improved seed availability, and financial services for Lablab farmers in Tanzania. To sustain the smallholder farmers' five livelihood assets from Lablab, researchers and policymakers must pay attention to the three linkages of the LVC.
Dolichos Lablab-an underutilized crop with future potentials for food and nutrition security: a review.
(Taylor & Francis Online, 2020-06-12) Minde, Josephine; Venkataramana, Pavithravani; Matemu, Athanasia
Achieving the Sustainable Development Goals (SDGs) particularly goal number two in developing countries by 2030 is challenging. The State of Food Security and Nutrition (2019) in the World show prevalence of undernourishment which has practically remained unchanged for the last three years. This calls for sustainable synergies between food and nutrition in addressing the challenge. Exploring the potential of underutilized legumes such as Dolichos Lablab () in improving food and nutrition security is of importance. Lablab is known among nutritious underutilized diversified legumes, which is drought tolerant relative to other legumes. However, it is less popular as human food. This review focuses on providing details on the nutritional potential of underutilized Lablab varieties for food availability, accessibility and satisfactorily utilization for improved livelihood. So far research attention has been focusing on good agronomic performance with less information on their nutritional quality and its contribution to the wellbeing of people. Both wild and cultivated Lablab accessions do differ morphologically and across diverse habitat environments. This may make them less known, untapped and underutilized despite its promising potential as a food resource in developing countries where malnutrition still exists. Efforts are needed to popularize high-quality nutritional accessions, enhancing their consumption and commercialization for feeding the ever-increasing population in the future.
Enhancing Food Grains Storage Systems through Insect Pest Detection and Control Measures for Maize and Beans: Ensuring Food Security Post-COVID-19 Tanzania
(MDPI, 2024-02-21) Chidege, Maneno; Venkataramana, Pavithravani; Ndakidemi, Patrick
COVID-19 poses a significant threat to the present and future of mankind. The emergence of diverse strains during the pandemic creates uncertainty regarding their disappearance or resurgence. Lockdown measures and travel restrictions impact national and household food systems, hindering the movement of people and goods. Effective COVID-19 control requires science-based preventive measures and consideration of food availability. In Tanzania, resource-constrained farmers rely on the self-storage of food crops. Precise pest control information and tailored detection/storage systems are essential for preserving major staple foods such as maize and beans, which face frequent infestation by beetles and moths. Traditional methods used before the pandemic are insufficient compared to advanced global alternatives. This paper reviewed about 175 publications from different databases, dated from 1984 to 2023 (2023 to 2014 = 134, 2013 to 2004 = 26 and 2003 to 1984 = 15), assessing storage management for maize and beans. Identifying gaps between Tanzania and global advancements aiming to empower farming communities with the latest technologies and ensuring food security amid the pandemic.
Evaluating Rhizobium and Bradyrhizobium species as potential biocontrol agents for root rot fungi in soybean seedlings
(Technology in Agronomy, 2024) Nakei, Monica; Venkataramana, Pavithravani; Ndakidemi, Patrick
Soybean (Glycine max) is among the legumes which are highly prone to soil-borne pathogens which causes root-rot diseases limiting the growth and development resulting to low yield of plants. This study was conducted to test the ability of three rhizobia strains, Rhizobium sp. TZSR12C, Rhizobium sp. TZSR25B and Bradyrhizobium sp. TZSR41A, in comparison with the commercial biocontrol (Trichoderma harzianum in suppressing the growth of root rot fungal pathogens (Fusarium solani, Rhizoctonia solani, Fusarium oxyporum, and Macrophominaphaseolina) under in vitro and greenhouse conditions. The rhizobium cell filtrates were used in testing their activities against fungal pathogens under in vitro while the solid biofertilizer formulations containing the respective rhizobia inoculants were used to inoculate the soybean seeds sown in pathogen contaminated soil under greenhouse conditions. Results showed that all rhizobia isolates and T. harzianum were capable of suppressing the fungal pathogens both under in vitro and greenhouse conditions with the highest inhibition zone (8.3 mm) and colony diameter (25.0 mm) being in Rhizobium sp. TZSR25B against F. oxyporum under in vitro conditions. Under greenhouse experiment, Rhizobium sp. TZSR12C had the highest performance in inhibiting the infection of plant up to 27.78% with severity of 5.56% in roots and 0.00% infection in foliage against the combination of F. solani, R. solani, F. oxyporum, and M. phaseolina. We found that, on their performance, the tested rhizobia strains can potentially be utilized as biocontrol agents against the fungal pathogens in the rhizosphere of soybean plants
Exploring the nutritional potentials of wild Vigna legume species for neo-domestication prospects
(Cambridge University Press, 2024-02-14) Harouna, Difo; Ndakidem, Patrick; Venkataramana, Pavithravani; Matemu, Athanasia
Projected increases in human population suggest that 70% more food will be needed in the near future, this makes it imperative to search for alternative food and feed sources for human and animal nutrition to feed the exponentially growing human population. According to the FAO 2019 report, the immense challenge of achieving the Zero Hunger target by 2030 is persistent. Exploring the unexplored, refining unrefined traits, cultivating the uncultivated, and popularizing the unpopular remain the most adequate steps proposed by researchers to achieve the domestication of the undomesticated for food and nutrition security. In that line of thought, this study explored the proximate composition of 87 accessions of four wild unexplored Vigna species (V. racemosa, V. ambacensis, V. reticulata, V. vexillata) in order to reveal information leading to their future domestication and utilization. Standard procedures and methods approved by the Association of Official Analytical Chemists were used in carrying out the proximate composition (%protein, %lipid, %fibre, %ash and % moisture and % carbohydrate) of the wild Vigna legumes. The study revealed that the wild Vigna species possess a large variation range of nutrient characteristics which could be exploited in the improvement of domesticated species or guide their domestication. It was also found that some individual wild accessions have higher nutrient, content as compared with domesticated ones which could be advantageous for bio-fortification or domestication. Indications relating to the candidate accessions favourable for dom
Farmers’ Participatory Plant Selection of Lablab (Lablab purpureus (L.) Sweet) in Tanzania
(Frontiers in Plant Science, 2022-06-23) Letting, Fanuel; Venkataramana, Pavithravani; Ndakidemi, Patrick
Farmer-participatory breeding approach is an important component in the crop improvement of lablab (Lablab purpureus (L.) Sweet). The study was carried out to obtain the knowledge, practices and preferences of lablab through 31 lablab growing farmers from Arusha, Kondoa, Karatu, Same and Babati districts of Tanzania toward initiating a lablab breeding program. Semi-structured questionnaires were administered and focused group discussions were held to collect data on the socio-demographic factors, production practices, constraints and farmer’s preferred traits of lablab. Selection of preferred traits and accessions was also done by the farmers in the field. Results showed that the chief constraints of lablab production are pests and diseases, poor marketability, low seed quality, inadequate rainfall, expensive agrochemicals, low yield, and poor storage facilities. The major pests are pod borer (field) and bruchids (storage). Preferred traits for lablab improvement include the development of insect pests and disease-resistant varieties, early maturing, high yield, black colored seed for market, short cooking time, and dense foliage. Genotypes EK2, D360, HA4, and D96 with preferred traits were identified by farmers, which forms critical decisions in crop improvement. This study describes the current view of lablab production and generates the understanding of farmers’ perceptions and preferences vital for breeding priorities and programs to increase its production, utilization and consumption.
Insecticidal Activity of Selected Plant-Derived Essential Oils against Papaya Mealybug (Paracoccus marginatus)
(MDPI, 2023-12-02) Mwanauta, Regina; Venkataramana, Pavithravani; Ndakidemi, Patrick
The current study aims to assess the effectiveness of three essential oils derived from neem, citrus, and garlic against papaya mealybug. Papaya seedlings were transplanted in the field in a completely randomized block design with eight treatments with four replications. The treatments included neem, citrus, and garlic oils in combination with isopropyl alcohol or paraffin oil as an adjuvant. Results from this study showed that neem oil at 1.5% + 0.2% isopropyl alcohol was effective against papaya mealybug by 93.0% equivalent to the positive control (imidacloprid) (99.4%), followed by citrus oil at 1.5% + isopropyl alcohol (76.3%) and citrus oil at 1.5% + paraffin oil (68.8%), compared with the untreated 0.01%. Similarly, application of the plant-derived essential oils and adjuvants resulted in positive effects on plant parameters (plant height, number of leaves, flower buds, number of fruits, and fruit weight) and, hence, increased papaya yield from an average of 38 to 90 fruits/plant at first harvest. The finding from this study provides an understanding of papaya farmers towards the use of natural plant products, particularly plant-derived essential oils, and their benefits, which may encourage farmers to increase papaya production and minimize the usage of synthetic pesticides to avoid pest resistance.
Lablab (Lablab Purpureus L. Sweet): Current Developments in Breeding and Prospects for Drought Tolerance, Improved Yield, and Sustainable Production in Sub-Saharan Africa (SSA)
(Springer, 2025-05-17) Missanga, Julius; Venkataramana, Pavithravani
Drought is the largest threat to crop production, especially in sub-Saharan Africa (SSA). Since we have a few crop species performing well in dry areas , knowledge on their responsesto drought stress could help us to identify the drought-tolerant genotypes. Lablab (Lablab purpureus L. Sweet) is the most drought-tolerant crop with a wide range of benefits as compared to other legumes. It is a farmers' resource crop with a multiple range of physiological, agronomic and nutritional values. It excels well in the sustainability of soil fertility and conservation agriculture. Farmers in arid and semi-arid regions rely on it for human consumption, animal feeding and income. Despite its potential, Lablab is still an underutilized crop in many countries, especially in SSA where the effects of climate change are most visible. The main reason why farmers in SSA are not benefiting much from this crop is a lack of improved varieties, particularly the high-yield , drought-tolerant varieties. The present advancements in plant breeding and their potential in research for drought tolerance, improved yield, and sustainable production in Lablab have become the main topic of this review study. The morphological, biochemical, and genomic potential of this crop have all been thoroughly examined in this study in order to endorse them for further breeding in drought tolerancee and yield improvement. With a small genome size (367 Mb) and a longer coding sequence (1276 bp) to exhibit more gene expression, Lablab becomes a crop of choice for the future sustainability in present effect of climate change. . Some of the ongoing research initiatives in Lablab suggest more screening of germplasm for drought tolerance especially at the seedling and reproductive stages so that to develop moisture stress-tolerant varieties . Additional research initiatives should also consider advanced gene analysis to assess DNA and RNA expressions on drought conditions and more studies on sequence-based markers-polymorphism contrasting for responses to the drought stress. It is finally proposed that the transferred quantitative traits loci (QTL) from other legumes could help to achieve the suitable varieties so that to shift Lablab to the industrial and economic crop in SSA.