Detection of Plasmodium species by microscopy has been the gold standard for diagnosis of malaria for more than a century. Despite the fact that there is a significant decline in the number of positive cases reported from microscopy, antimalarial drugs prescriptions are on continuous increase as patients present with symptoms of malaria. This makes it difficult to establish accuracy, sensitivity and specificity of light microscopy in diagnosis of malaria in epidemic areas. This study was designed to compare microscopy with polymerase chain reaction as diagnostic methods for malaria in three epidemic areas in Kenya. A total of 356 patients presenting with malaria symptoms were diagnosed by microscopy and dried blood filter paper spots were collected from patient in Kisii, West Pokot and Narok districts. Plasmodium falciparum DNA was extracted from the dried blood filter samples. Primers specific for the Plasmodium Species were designed and used in a two step amplification of the Pfmdr gene. The PCR products were analyzed in ethidium bromide stained 1.5% agarose gel. It was found that 72 out of 350 specimens diagnosed as negative were positive for P. falciparum by nested PCR, while 6 which were microscopy positive were confirmed so by nested PCR. This study demonstrates that there is a high level of misdiagnosis which may either lead to denial for deserved treatment or undeserved treatment. Nested PCR detection of malaria parasites is a very useful complement to microscopy although it is expensive and takes long time. Additionally, smear negative patients suspected to have malaria should be subjected to PCR diagnosis to improve rational drug use. The economic burden of misdiagnosis and mistreatment of malaria outweighs that of PCR diagnosis, hence this diagnostic mode could be tenable in the long run even in rural areas.
Azolla fern is invasive in Mwea Irrigation Scheme in Kenya and its management in paddy rice fields is a challenge to farmers. A survey was undertaken to establish farmers’ knowledge and potential nitrogen contribution by Azolla in the paddies. The Scheme was stratified into seven sections and a questionnaire administered to 250 farmers. Data were collected on awareness levels, source, trend of infestation, abundance, fertilizer regimes and management practices. Five farms from each of the sections were also sampled for Azolla coverage and tissue N levels analyzed. Survey data were analyzed using SPSS software and interpreted using descriptive statistics. Biomass sampling data were analyzed using SAS software and means separated using the least significant differences at P ≤ 0.05. The results demonstrated that Azolla has infested nearly all the paddy farms in Mwea. Azolla invasion occurred more than 10 years ago and coverage per unit area was on a decline and stood at 25%. Water shortage and herbicide use were the main reasons associated with this trend. Azolla is conspicuously noticed at transplanting and weeding times. The presence of Azolla in Mwea is enhanced by widespread use of P and K fertilizers and continuous paddy cropping, thus providing a suitable environment for Azolla growth. Azolla was reported to enhance soil fertility, rice yield and yield components. The maximum Azolla biomass coverage was 14.92 t/ha, with a potential nitrogen contribution of 37.6 kg N/ha. Azolla is invasive in Mwea, widespread, beneficial to paddies and with a high potential N contribution.
Azolla tissue contains 5% N, which is slowly released into the soil upon decomposition. Timing of incorporation is therefore important for maximum benefit to a crop. The effect of time to incorporate Azolla biomass on growth and yield of rice was investigated in Mwea-Kenya. Treatments consisted of 7.5 t ha-1 Azolla biomass applied at transplanting, 7.5 t ha-1 Azolla applied at 21 days after transplanting (DAT) and 30 kg N ha-1 inorganic N applied in splits at O, 21 and at 55 DAT. There were control treatments without Azolla and without inorganic N application. The treatments were laid out in a Randomized Complete Block Design (RCBD) with three replications. Phosphorus and potassium were applied at 50 Kg ha-1 each as P 2 O 5 and K 2 O. Plant height and tiller numbers were recorded at 21 (rooting/tillering), 32 (tillering), 42 (maximum tillering), 60 (flowering) and 75 DAT (heading) while yield parameters were determined at physiological maturity (120 DAT). Data were analysed using SAS software and means separated using the least significant difference test (p≤0.05). Azolla incorporation at transplanting significantly enhanced panicle m-2 , grain weight and grain yield while incorporating it at 21 DAT only significantly enhanced panicle m-2. Higher environmental temperatures enhanced Azolla effect. The effect of Inorganic N significantly increased plant height, tiller number, grain weight and spikelets panicle-1. However, percentage grain filling was reduced. The effect of interaction between Azolla application and inorganic N was significant on spikelets panicle-1 and grain weight. Observations therefore indicate that the effect of Azolla on yield and yield components was more when incorporated at transplanting.
Semi-arid eastern Kenya is a fragile ecosystem with continuous cultivation of dryland pulses and grains. Farmers use artificial fertilizers most of which are deleterious to the environment. Previous studies have shown that soil microbes in the rhizosphere could be used to sustainably enhance levels of soil mineral nutrients and soil health. However, few studies have examined fungal diversity in the rhizosphere of wild and native Aspilia pruliseta shrub. In this study, amplicons of Internal Transcribed Spacer (ITS) region on Total Community DNA using Illumina sequencing were used to explore the fungal community composition within the rhizosphere. Operational taxonomic units (OTUs) were analyzed using QIIME 1.8.0, taxonomy assigned via BLASTn against SILVA 119 database. Hierarchical clustering was done using R programming software. 72,093, 50,539 and 43,506 sequence reads were obtained from samples MC1 a , MC2 a and MC3 a respectively representing rhizosphere depth 0-20 cm, 21-40 cm and 41-60 cm. A total of 373 OTUs were realized at 3% genetic distance. Taxonomic analysis revealed that the genera Glomus was most prevalent in all soil depths with 85.60 % of the OTUs in depth 0-20 cm, 69.04 % in depth 21-40 cm and 48.45 % in depth 41-60 cm. The results revealed high levels of obligate arbuscular mycorrhiza fungi that if commercially cultured could enhance phosphates uptake in crops.
<p><em>Azolla</em> is a floating pteridophyte, which forms an association with an endosymbiont, the nitrogen-fixing cyanobacterium <em>Anabaena azollae</em>. In Mwea Irrigation Scheme paddies, <em>Azolla</em> biomass coverage ranges from 25 to 50 % with a high biomass growth rate and this has caused a challenge in its management. Knowledge on the effect of <em>Azolla</em> biomass on rice tillering, root development and grain yield are important in order to exploit its potential benefits in Mwea Irrigation Scheme, where nearly 60 % of the total rice in Kenya is produced. The effect of <em>Azolla</em> on tillering, plant biomass, adventitious roots development, basal internode growth and yield of rice, was studied during 2015/2016 short and long rains. <em>Azolla</em> was inoculated in 30 cm x 30 cm plastic pots planted with rice variety Basmati 370. Controls where no <em>Azolla</em> was inoculated were included. Tiller number, plant height, flood water temperature and pH were determined at 21, 32, 42, 60 and 75 days after transplanting (DAT). At 120 DAT, grain yield and yield components were determined. Length of basal node and adventitious root were measured and dry biomass weights of, root and above ground biomass determined. Water temperature in <em>Azolla</em> inoculated pots were significantly lower than in controls by 0.8 °C and 1.3 °C in the second and first seasons respectively with a daily fluctuation of 2 °C. The pH of flood water in potted rice inoculated with <em>Azolla</em> was significantly lower than in control. <em>Azolla</em> inoculated potted rice had significantly higher number of tillers/m<sup>2</sup>, spikelets per panicle<sup>-1</sup>, panicle size m<sup>-2</sup>, 1000 grain weight and plant biomass than in non-inoculated controls. Adventitious roots were significantly longer and more per unit area in all treatments than in controls. The basal stem node length was significantly shorter while root biomass was less for the <em>Azolla</em> inoculated potted rice than in controls. In all treatments, <em>Azolla</em> doubled its biomass within an average of 5 days.</p><p> </p><p> </p>
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.