Forecasting rainfed sorghum yield using satellite-derived vegetation indices with limited ground-based information in Gadarif region, eastern Sudan

A practical crop growth and yield monitoring system based on satellite data is required and fundamental not only for precision farming, but also very useful for global food security enhancement. This study was performed to determine the optimal vegetation index and also to identify the best time for making a reliable crop yield forecast in one of the major sorghum-growing region (Gedarif State, Sudan). The study was also aimed to develop a simple yield prediction model which was later validated using an official yield data acquired during 2013 and 2014 cropping seasons from the Department of Information System and Statistical Analysis of the State Ministry of Agriculture, Gedarif State. The study used NASA’s multi-temporal MODerate resolution Imaging Spectroradiometer (MODIS) land products with limited ground information. Relationship between sorghum yield and crop reflectance indicated that normalized difference vegetation index (NDVI) at the third dekad of September (Sep.III) is the most appropriate to develop sorghum yield prediction model with higher R2 value of 0.77 (p<0.05) compared to other vegetation indices (normalized ratio vegetation index, NRVI and soil-adjusted vegetation index, SAVI). The plotting of estimated yield against actual yield during 2013 and 2014 cropping seasons revealed strong positive and linear correlations (R2 = 0.64 (p=0.06) and 0.74 (p<0.05), respectively with average R2 = 0.71 (p<0.001) for both seasons. This study concluded that a good prediction of rainfed sorghum yield could be achieved more than 30 days before harvesting with quick, accurate and cost-effective method compared to traditional field surveys

Phosphorus sorption capacity as a guide for phosphorus availability of selected Sudanese soil series

Crop response to phosphorus application is often erratic in most soil types in Sudan. This inconsistent response is believed to be due to the alkaline nature of most soils in the country. Phosphorus adsorption isotherms and buffering capacity are powerful tools for predicting response of different soil types to apply P fertilisers. This study was carried out to investigate the degree of P adsorption capacity in some soils in Sudan and the consequential effect on P availability. A laboratory experiment was conducted on six soil samples of selected soil series from different sites in Sudan. Samples were equilibrated with different P concentrations, prior to evaluating the sorption potential and binding intensity. Results indicated that at any specific P concentration, the amount of P sorbed by the Entisols was higher than for the other soils. The order of soils according to their adsorption capacities using Freundlich equation were 917, 330, 315, 269, 214 and 80 mg P kg-1 soil for River Nile banks (Entisols), Dongola 2 (Aridisols), Permanent Fallow (Virgin Vertisols), Remitab (Cultivated Vertisols), Khashm elgirba (Vertisols) and Dongola1 (Aridisols), respectively. The soil\u2019s ability to sorb added P increases due to increase in affinity sites of clay and iron content.La r\ue9ponse des cultures \ue0 l\u2019application du phosphore est souvent impr\ue9dictible dans beaucoup de types de sols du Sudan suite \ue0 la nature alkaline de laplupart des sols dans ce pays. Les isothermes d\u2019adsorption du phosphore et la capacit\ue9 tampon sont des outils les plus efficaces pour pr\ue9dire la r\ue9ponse de diff\ue9rents types de sols \ue0 l\u2019application des engrais phosphat\ue9s. Cette \ue9tude \ue9tait conduite pour \ue9valuer la capacit\ue9 d\u2019adsorption du phosphore dans quelques sols du Sudan et ses effets sur le phosphore disponible. Un essai au laboratoire \ue9tait conduit sur six \ue9chantillons de sol s\ue9lectionn\ue9s des s\ue9ries de diff\ue9rent sites au Sudan. Ces \ue9chantillons \ue9taient \ue9quilibr\ue9s avec diff\ue9rentes concentrations de P avant l\u2019\ue9valuation du potentiel d\u2019adsorption et l\u2019intensit\ue9 d\u2019adh\ue9sion. Les r\ue9sultats ont indiqu\ue9 qu\u2019\ue0 une certaine concentration sp\ue9cifique de P, la quantit\ue9 de P fix\ue9 par les Entisols \ue9tait plus \ue9lev\ue9e que celle des autres sols. Sur base de l\u2019Equation de Freundlich, l\u2019ordre de sols en rapport avec leur capacit\ue9 d\u2019adsorption \ue9tait de 917, 330, 315, 269, 214 et 80 mg P kg-1 de soil pour les bordures de la rivi\ue8re Nile (Entisols), Dongola 2 (Aridisols), la jach\ue8re permanante (Vertisols vierge), Remitab (Vertisols cultiv\ue9s), Khashm elgirba (Vertisols) et Dongola 1 (Aridisols), respectivement. La capacit\ue9 du sol \ue0 fixer P augmente suite \ue0 l\u2019augmentation des sites d\u2019affinit\ue9 d\u2019argile et de la teneur en fer

A comparison of methods to assess the antimicrobial activity of nanoparticle combinations on bacterial cells

Copyright: © 2018 Bankier et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.BACKGROUND: Bacterial cell quantification after exposure to antimicrobial compounds varies widely throughout industry and healthcare. Numerous methods are employed to quantify these antimicrobial effects. With increasing demand for new preventative methods for disease control, we aimed to compare and assess common analytical methods used to determine antimicrobial effects of novel nanoparticle combinations on two different pathogens. METHODS: Plate counts of total viable cells, flow cytometry (LIVE/DEAD BacLight viability assay) and qPCR (viability qPCR) were used to assess the antimicrobial activity of engineered nanoparticle combinations (NPCs) on Gram-positive (Staphylococcus aureus) and Gram-negative (Pseudomonas aeruginosa) bacteria at different concentrations (0.05, 0.10 and 0.25 w/v%). Results were analysed using linear models to assess the effectiveness of different treatments. RESULTS: Strong antimicrobial effects of the three NPCs (AMNP0-2) on both pathogens could be quantified using the plate count method and flow cytometry. The plate count method showed a high log reduction (>8-log) for bacteria exposed to high NPC concentrations. We found similar antimicrobial results using the flow cytometry live/dead assay. Viability qPCR analysis of antimicrobial activity could not be quantified due to interference of NPCs with qPCR amplification. CONCLUSION: Flow cytometry was determined to be the best method to measure antimicrobial activity of the novel NPCs due to high-throughput, rapid and quantifiable results.Peer reviewe

Estimation of Phenolic and Flavonoid Compounds and Antioxidant Activity of Spent Coffee and Black Tea (Processing) Waste for Potential Recovery and Reuse in Sudan

This study aimed to evaluate the antioxidant power associated with spent coffee and black tea processing waste. Ethanolic extracts from the samples were prepared in order to determine the quantities/concentrations of the phenolic and flavonoid compounds, polyphenols, and associated levels of antioxidant activity. The results showed that both the spent coffee and black tea waste had high amounts of phenolic compounds and high antioxidant activity rates. The total phenolic and flavonoids content was found to be significantly higher (p < 0.05) in the spent black tea than in the spent coffee. The total phenolic content was found to be 152.8 and 97.87 mg of gallic acid equivalent/g, while the total amount of flavonoids was found to be 47.40 and 34.32 mg catechin/g in spent black tea and coffee, respectively. However, the spent coffee had a significantly higher (p < 0.05) antioxidant activity than that detected in the spent black tea (57.83%). Consequently, the results revealed that the waste residue of spent coffee and black tea may be considered as natural sources of bioactive compounds and that there may be potential for recycling these waste products, which could be applied in different industries to further develop functional foods