Endophytes vs tree pathogens and pests: can they be used as biological control agents to improve tree health?

Like all other plants, trees are vulnerable to attack by a multitude of pests and pathogens. Current control measures for many of these diseases are limited and relatively ineffective. Several methods, including the use of conventional synthetic agro-chemicals, are employed to reduce the impact of pests and diseases. However, because of mounting concerns about adverse effects on the environment and a variety of economic reasons, this limited management of tree diseases by chemical methods is losing ground. The use of biological control, as a more environmentally friendly alternative, is becoming increasingly popular in plant protection. This can include the deployment of soil inoculants and foliar sprays, but the increased knowledge of microbial ecology in the phytosphere, in particular phylloplane microbes and endophytes, has stimulated new thinking for biocontrol approaches. Endophytes are microbes that live within plant tissues. As such, they hold potential as biocontrol agents against plant diseases because they are able to colonize the same ecological niche favoured by many invading pathogens. However, the development and exploitation of endophytes as biocontrol agents will have to overcome numerous challenges. The optimization and improvement of strategies employed in endophyte research can contribute towards discovering effective and competent biocontrol agents. The impact of environment and plant genotype on selecting potentially beneficial and exploitable endophytes for biocontrol is poorly understood. How endophytes synergise or antagonise one another is also an important factor. This review focusses on recent research addressing the biocontrol of plant diseases and pests using endophytic fungi and bacteria, alongside the challenges and limitations encountered and how these can be overcome. We frame this review in the context of tree pests and diseases, since trees are arguably the most difficult plant species to study, work on and manage, yet they represent one of the most important organisms on Earth

Endophytes vs tree pathogens and pests: can they be used as biological control agents to improve tree health?

Like all other plants, trees are vulnerable to attack by a multitude of pests and pathogens. Current control measures for many of these diseases are limited and relatively ineffective. Several methods, including the use of conventional synthetic agro-chemicals, are employed to reduce the impact of pests and diseases. However, because of mounting concerns about adverse effects on the environment and a variety of economic reasons, this limited management of tree diseases by chemical methods is losing ground. The use of biological control, as a more environmentally friendly alternative, is becoming increasingly popular in plant protection. This can include the deployment of soil inoculants and foliar sprays, but the increased knowledge of microbial ecology in the phytosphere, in particular phylloplane microbes and endophytes, has stimulated new thinking for biocontrol approaches. Endophytes are microbes that live within plant tissues. As such, they hold potential as biocontrol agents against plant diseases because they are able to colonize the same ecological niche favoured by many invading pathogens. However, the development and exploitation of endophytes as biocontrol agents will have to overcome numerous challenges. The optimization and improvement of strategies employed in endophyte research can contribute towards discovering effective and competent biocontrol agents. The impact of environment and plant genotype on selecting potentially beneficial and exploitable endophytes for biocontrol is poorly understood. How endophytes synergise or antagonise one another is also an important factor. This review focusses on recent research addressing the biocontrol of plant diseases and pests using endophytic fungi and bacteria, alongside the challenges and limitations encountered and how these can be overcome. We frame this review in the context of tree pests and diseases, since trees are arguably the most difficult plant species to study, work on and manage, yet they represent one of the most important organisms on Earth

A Geochemical Survey of Groundwater in Khana and Gokana Local Government Areas of Rivers State, Nigeria

Fifteen groundwater samples from functional boreholes in Khana and Gokana areas of Rivers State were collected and analysed for various physico-chemical parameters using standard field and laboratory techniques. This was done to assess the suitability of the water for domestic and other purposes on the basis of the parameters studied. Results show the following mean values for the physical parameters: temperature, 24.8\ub0C; Electrical Conductivity (EC), 15.9 \u3bcs/cm. For the chemical parameters, the following average concentration levels were obtained: pH 6.99; total iron, 0.04mg/l; magnesium 0.85mg/l; sodium, 0.89mg/l; and potassium 0.05mg/l. Others include bicarbonate, 8.19mg/l; chloride 32.52mg/l; sulphate, 0.92mg/l; nitrate, 0.82mg/l; and Total Dissolved Solids (TDS), 7.73mg/l. These results show that the groundwater in these areas is slightly acidic to slightly basic, soft and low in dissolved constituents. Chloride contents in the water show salt-water encroachment into the aquifers in both areas. However, when compared with the World Health Organisation (WHO) standards for drinking water, the results show that the water is suitable for drinking and other domestic purposes in view of the parameters determined. It is also suitable for agricultural purposes. The major sources of ions in the water include mineral assemblages in the rocks, geochemical processes operating within the groundwater system, as well as atmospheric precipitation. Moreover, these geochemical processes, and exploitation of water from different depths are suggested as reasons for the variations in the geochemical parameters with borehole locations. @JASE

Assessment of shallow groundwater quality and its suitability for drinking and agricultural uses in parts of Ahoada east, Rivers state, Nigeria

This study aims at determining the quality of the groundwater in parts of Ahoada East, Rivers State, Nigeria to establish its suitability for domestic, agricultural and industrial purposes. Ten (10) groundwater samples were obtained from boreholes and analysed using standard methods. The result shows a low pH value ranging from 4.66 – 5.92 with a mean value of 5.25. The iron content of nine (9) borehole samples was high except for borehole 1(AH1) which show a significantly low iron content. Other parameters met the World Health Organization (WHO) standards for drinking water and domestic usage. The Sodium Adsorption Ratio is low, making it suitable for irrigation. For industrial purposes, the water should be treated according to the industrial process in view before usage. Furthermore, water for drinking should be treated mildly, due to low pH and high iron content. Polyvinyl chloride materials (PVC) and other non-corrosive materials should be used for the construction of boreholes within the area to reduce damage to plumbing materials. Groundwater monitoring, effective and holistic management strategy should be employed in the study area.Key Words: Groundwater, hydrogeochemistry, water quality, Ahoada, Rivers State, Nigeri

A Geochemical Survey of Groundwater in Khana and Gokana Local Government Areas of Rivers State, Nigeria

Fifteen groundwater samples from functional boreholes in Khana and Gokana areas of Rivers State were collected and analysed for various physico-chemical parameters using standard field and laboratory techniques. This was done to assess the suitability of the water for domestic and other purposes on the basis of the parameters studied. Results show the following mean values for the physical parameters: temperature, 24.8°C; Electrical Conductivity (EC), 15.9 ms/cm. For the chemical parameters, the following average concentration levels were obtained: pH 6.99; total iron, 0.04mg/l; magnesium 0.85mg/l; sodium, 0.89mg/l; and potassium 0.05mg/l. Others include bicarbonate, 8.19mg/l; chloride 32.52mg/l; sulphate, 0.92mg/l; nitrate, 0.82mg/l; and Total Dissolved Solids (TDS), 7.73mg/l. These results show that the groundwater in these areas is slightly acidic to slightly basic, soft and low in dissolved constituents. Chloride contents in the water show salt-water encroachment into the aquifers in both areas. However, when compared with the World Health Organisation (WHO) standards for drinking water, the results show that the water is suitable for drinking and other domestic purposes in view of the parameters determined. It is also suitable for agricultural purposes. The major sources of ions in the water include mineral assemblages in the rocks, geochemical processes operating within the groundwater system, as well as atmospheric precipitation. Moreover, these geochemical processes, and exploitation of water from different depths are suggested as reasons for the variations in the geochemical parameters with borehole locations. @JASE

A Preliminary Evaluation of Otamiri River Sands for the Production of Plain Glass

Grain-size distribution and chemical analyses were carried out on four sand samples randomly taken from the bank of Otamiri River around Chokocho and Umuanyaga, Etche Local Government Area, Rivers State. This was done to assess the purity and suitability of the sands for the making of plain glass. Results of grain-size analysis show that 86% of the sand particles fall between 0.125mm and 1.2mm, which is within the ideal sand fraction range used for glass making. Chemical analysis shows the sand to contain more than 99% silica (SiO2), very low content of iron (0.0017 to 0.0039ppm), chromium (0.000022 to 0.000032ppm), titanium (0.049 to 0.066ppm) and calcium (0.000001 to 0.000003ppm). Others include Aluminium (0.00126 to0.0103ppm), potassium (0.0002 to 0.0042ppm), Magnesium (0.0001 to 0.0002ppm), and Sodium (0.005 to 0.038ppm). The concentration levels of these elements in the samples conform with internationally acceptable standards for glass production. @JASE

THE EFFECT OF CRUDE OIL SPILL ON PLANKTON ABUNDANCE IN SANTA BARBARA RIVER, NEMBE, BAYELSA STATE

Plankton are the main varied group of aquatic organisms that play major roles in the aquatic environment as primary producers. The study focused on the effect of crude oil Spill on Plankton composition in Santa Barbara River, Nembe, Bayelsa State. Samples were collected and preserved in 5% formalin from ten (10) water sampling locations with one serving as control in four replicates. Standard plankton net of 55m mesh size was used for sample collection. Data recovered from the study showed the occurrence of 61 species of plankton belonging to two (2) classes, 8 families and genera. A total of 486 organisms were recovered from the surface water out of which 394 (81.06%) were phytoplankton and 92 (18.93%) were zooplankton. The families of planktons identified were Bacillariophyceae, Cyanophyceae, Chlorophyceae, Xanthophyceae, Euglenophyceae, Dinophyceae, Copepod, and Cladocera. The family Bacillariophyceae had the highest species diversity (144) within WO/SW1 having the highest species richness of (96) which represented (19.75%) of the total plankton population recovered in the study. Sampling station WO/SW2 had a species richness of 64 (13.16%) while BA/SW8 had the lowest species richness of 32 representing (6.58%) of the recovered plankton population in the study. The result shows a decrease in the distribution and abundance of the plankton species in the Santa Barbra River. The results indicate pollution caused by hydrocarbon spillage. There was phytoplankton bloom when compared to zooplankton. The zooplanktons were more sensitive to the hydrocarbon spill than phytoplanktons this is linked to hypoxic nature of surface water following the hydrocarbon spill incident significantly affecting zooplankton abundance and diversity in the Santa Babra River

Evaluation of Petroleum Source Rock Using Well Logs in the Niger Delta Region of Nigeria

Petroleum source rock potential evaluation was carried out on eight wells of the Niger Delta’s Agbada Formation by assessing some source parameters from well logs and through well logs analysis based on organic matter effect and relationship on and with well logs. Source rock determinant parameters such as volume of shale (Vsh), total organic content (TOC), and amount of generated hydrocarbon (S2) was derived from well logs following established organic matter effects on well logs using Schlumberger's Techlog 2015 software, while hydrogen index (HI) was calculated using known values of TOC and S2 respectively. Well log data used for the analysis includes GR log, resistivity, sonic and Density logs. Apart from deriving source rock parameters, the well logs were also used to identify, quantify and somewhat determine mature zones of source rock intervals by correlation with TOC, S2, and HI source parameters respectively, Therefore, a source interval criterion composing of high GR log, high resistivity, high sonic and low-Density was developed alongside source rock parameters. Results of the analysis in the area show poor to fair source rock quality rating in terms of TOC, and insufficient source rock thickness fit for sustaining a world-class petroleum province like the ND petroleum province and further depicting that the Agbada FM may not be the principal source rock of the area. It is, therefore, recommended that more elaborate studies covering greater depths of the Agbada FM be carried out in other to properly represent the true source quality of the area