Phosphorus solubilizing bacteria (PSB) are a category of microbes that transform insoluble phosphates in soil into soluble forms that crops can utilize. Phosphorus in natural soils is abundant but poorly soluble. Hence, introducing PSB is a safer way of improving its solubility. The aim of this study was to genetically characterize and determine the mineralization capability of selected PSB colonizing rhizospheres of common beans in Western Kenya. Seven potential phosphorus solubilizing bacteria (PSB) were isolated from various subregions of Western Kenya. 16S ribosomal RNA gene sequencing and National Center for Biotechnology Information (NCBI), Basic Local Alignment Search Tool (BLAST) identified the isolates. The phosphate solubilization potential of the isolates was evaluated under agar and broth medium of National Botanical Research Institute’s phosphate (NBRIP) supplemented with tricalcium calcium phosphate (TCP). Identified isolates were as follows: KK3 as Enterobacter mori, B5 (KB5) as Pseudomonas kribbensis, KV1 as Enterobacter asburiae, KB3 as Enterobacter mori, KK1 as Enterobacter cloacae, KBU as Enterobacter tabaci, and KB2 as Enterobacter bugandensis. The strains B5 and KV1 were the most effective phosphorus solubilizers with 4.16 and 3.64 indices, respectively. The microbes converted total soluble phosphate concentration in broth medium which was 1395 and 1471 P μg/mL, respectively. The least performing isolate was KBU with a 2.34 solubility index. Significant ( ≤ 0.05) differences in plant biomass for Rose coco and Mwitemania bean varieties were observed under inoculation with isolates B5 and KV1. PSB isolates found in common bean rhizospheres exhibited molecular variations and isolates B5 and KV1 are the potential in solving the insufficiency of phosphorus for sustainable crop production.

An Algorithm for Estimating Resistance Magnitude of Plants Against Disease Establishment and Pathogen Virulence Levels

Brachiaria is a newly introduced forage grass in Kenya and other countries that has potential for improving livestock productivity but there is limited availability of seed this has become a major constraint. Pastures in western Kenya faces both pathological and physiological problems associated with both biotic and abiotic factors that leads to poor livestock production especially in the dairy industry. This research study focused on evaluating disease tolerance and growth potential of selected Brachiaria cultivars Xaraes (Xaraes palisade), Piata (Piatã palisade), MG4 in the selected agro-ecological zones of Western Region, Kenya. Mulato II grass was included as a control. The experiment was replicated three times at two different agro-ecological zones namely KALRO Kakamega LM2 and KALRO Alupe, Busia LM1 agro ecological zones therefore this study was a 2×3×5 factorial laid in a split plot. Root splits used as planting material were sourced from KALRO Kakamega farm. Phosphate fertilizer at the rate 40 kg/ha P2O5 were used at planting and the crop was top dressed with Nitrogen fertilizer at the rate 100 kg/ha N. Data collected included number of tillers, plant height at different stages, light interception, leaf area index and diseases incidence on the seeds. In LM1 Mulatto II had the highest height and Basilisks had the lowest height and vice versa for LM2. In both agro-ecological zones Basilisks had the highest number of tillers. In terms of disease establishment, in LM2 (KALRO-Kakamega); Basilisks was the most affected cultivar by both false smut and ergot diseases at 58% and 69.33% incidences respectively. MG4 had the least ergot incidence at 41%, while Xaraes had the least incidence for false smut at 32%. In LM 1 (Alupe Busia), no cultivar exhibited disease. Most cultivars intercepted light higher in LM2 and lower in LM1. Mulatto II and Xaraes had the highest and lowest light interception respectively in LM1 (Alupe Busia), while Basilisks and Xaraes had the highest and lowest interceptions respectively in LM2 (KALRO-Kakamega). The trends were the same in terms of LAI though MG4 had the lowest LAI in LM1. Through this study Basilisks, Xaraes, Mulatto II and Piata were moderately tolerant to ergot disease while MG4 was highly tolerant. Basilisks and MG4 were moderately tolerant to false smut disease while Xaraes had high tolerance levels This research serves as a baseline for future research on Brachiaria forage yield and provide knowledge-based information on production of high quality Brachiaria seeds with the view of enhancing their availability scaling-up Brachiaria forage production to enhance dairy productivity in smallholder farm.

Potato (Solanum tuberosum) is a key staple crop in Kenya, where plant-parasitic nematodes are among the most damaging yield constraints for smallholder farmers. This study evaluated fluopyram-treated banana fibre paper, a biodegradable carrier for targeted delivery of ultra-low nematicide doses, under on-farm conditions in Nyandarua County over three consecutive cropping seasons across properly and poorly managed fields. Seventeen nematode genera were identified, with Helicotylenchus and Globodera (potato cyst nematode, PCN) recording the highest population densities. Fluopyram-treated banana paper significantly suppressed Globodera juvenile densities and reduced total nematode reproductive factors by ≥26% and PCN cyst multiplication factors, effects most pronounced under poor management. No significant nematode suppression was observed under good management. Potato yield and quality responded positively to fluopyram treatment: total yield approximately doubled in well-managed plots and increased by ~50% in poorly managed plots relative to untreated controls. Fluopyram-treated plots also produced a higher proportion of large-grade tubers under proper management, improving marketable yield. These findings demonstrate that banana fibre technology can effectively manage nematode pests under variable real-world smallholder conditions, with yield benefits amplified by good agronomic practices. The technology offers a practical, climate-smart and sustainable nematode management tool, with potential for wide adoption across sub-Saharan Africa.

Potato (Solanum tuberosum) is a key staple crop in Kenya, where plant-parasitic nematodes are among the most damaging yield constraints for smallholder farmers. This study evaluated fluopyram-treated banana fibre paper, a biodegradable carrier for targeted delivery of ultra-low nematicide doses, under on-farm conditions in Nyandarua County over three consecutive cropping seasons across properly and poorly managed fields. Seventeen nematode genera were identified, with Helicotylenchus and Globodera (potato cyst nematode, PCN) recording the highest population densities. Fluopyram-treated banana paper significantly suppressed Globodera juvenile densities and reduced total nematode reproductive factors by ≥26% and PCN cyst multiplication factors, the effects most pronounced under poor management. No significant nematode suppression was observed under good management. Total yield in fluopyram treatment approximately doubled in well-managed plots and increased by ~50% in poorly managed plots relative to untreated controls. Fluopyram-treated plots also produced a higher proportion of large-grade tubers under proper management, improving marketable yield. These findings demonstrate that banana fibre technology can effectively manage nematode pests under variable real-world smallholder conditions, with yield benefits amplified by good agronomic practices. The technology offers a practical, climate-smart, and sustainable nematode management tool, with potential for wide adoption across sub-Saharan Africa.