This study was conducted with the aim of isolating and identifying endophytic bacteria associated with bananas in Kenya and assessing their functional potentiality as biological fertilizers. Banana material was collected from two different banana cultivars in five different geographical regions and bacteria were isolated using five different isolation media. Whole-cell matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF/MS) analysis was used for microorganism profiling. Protein from the living cells were extracted using the ethanol/formic acid extraction procedure and intact molecular weights of the ionized proteins directly measured and the pattern of the protein molecular weights used as fingerprints. Forty three isolates were selected for partial 16S rRNA gene sequencing. Isolates were characterized on the basis of their in-vitro plant growth-promoting activities that included abilities to fix free nitrogen, solubilize phosphates and produce siderophores. The isolates were identified as Serratia,

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In recent years, essential oils (EOs) as alternatives to synthetic pesticides in managing pests have been assessed. The use of bioinsecticide in pest management is encouraged in agroecology for a sustainable agricultural system. Essential oils of Lantana camara L. leaves from different climatic zones of Kenya were extracted by steam distillation and analyzed through GC-MS to identify the compounds. The contact toxicity and repellent activity of EOs against the invasive tomato pest, Tuta absoluta, were tested. The toxicological assays were performed following the leaf-dip bioassay protocol, while the repellency activity was performed using the repellent response method for phytophagous pests and the data analyzed using the ANOVA test. It was found that L. camara EO has a good insecticidal activity with higher mortality (89%) on the 2 nd instar larvae with a higher dosage (0.01 µl/µl). The repellence test also showed a higher average repellence (93.44%) effect with a higher dosage (0.01 µl/µl) of the EOs. According to these results, the EO of L. camara may well be a sustainable, eco-friendly alternative for synthetic insecticide in the T. absoluta management program.

The objectives of this study were to assess (a) the efficiency of lemon and pineapple juices and the concentration and time needed to release more than 50% of available phosphorus from phosphate rock (PR), and (b) the effect of different types of PR management on carrot yields, nutrient uptake, and phosphorus use efficiency. Field trials were set up at two sites with humic andosols and orthic acrisols over two seasons in Kenya. In a randomized complete block design, replicated three times, the following treatments were compared: (i) composted dissolved PR in lemon juice; (ii) powdered PR composted; (iii) dissolved PR in lemon juice added to compost; (iv) powdered PR and compost; (v) triple superphosphate and compost; (vi) compost alone; (vii) triple superphosphate and Tithonia diversifolia mulch; with (viii) un-amended soil as a control. Lemon juice was effective in solubilizing PR, releasing 63% of the total phosphorus applied into available phosphorus, compared to 11% for pineapple juice and 6% for water. The combined application of compost and PR dissolved in lemon juice at planting significantly increased phosphorus and potassium uptake, phosphorus use efficiency, and carrot yields that was comparable to the use of triple superphosphate and compost. The study concludes that the dissolution of phosphate rock with lemon juice at a ratio of 1:5 phosphate rock to lemon juice and its combined application (immediately after dissolution) with compost at planting improves nutrient uptake, phosphorus use efficiency, and crop yields. We recommend further studies to explore the possibility of using citrus peels or other acidic organic materials to enhance the solubility of phosphate rock, and to assess their practical feasibility and the economic advantage(s) in the large-scale production of high value crops.

Studies examining the variability in wild plant metabolic expression propose that environmental factors significantly influence the essential oil (EO) quality and quantity in a plant. Lantana camara is a widely distributed invasive plant species worldwide. However, its immense metabolites can become a source of novel compounds to produce biopesticides in the agricultural industry. Although, the quality aspect has to be considered due to the environmental influence on the metabolites synthesised. Therefore, this research aimed to understand the influence of environmental factors and how it shapes the plant’s metabolite profile in multiple populations of L. camara. Leaf samples were collected from six different geographic regions of Kenya and the corresponding monthly climatic data and soil samples. GC-MS data from leaf EO were analysed with environmental variables (climate and soil data) using unimodally unconstrained and constrained ordination methods for untargeted metabolomics analysis. Partial Least Squares-Discriminant Analysis (PLS-DA) and Random Forests (RF) were used to confirm the variability further. Seasonal and regional variability was observed for secondary metabolites (SMs) in the leaf EO, which correlated to climatic factors and soil attributes. We highlight the season-al-geographic metabolism relationship for L. camara and the combined analytical approach to obtain data that contributes to understanding the influence of environmental factors on the synthesis and accumulation of SMs. This research will have all-embracing implications for maximising phytochemical uniformity.