Attacks by Termites (Blattoptera: Insecta) in cassava crops (Manioth esculenta Crantz.) in Daloa (Center-West, Côte d’Ivoire)

A study was carried out on the attack of termites in three cassava plots located in the zone of Daloa (town in the center-west of the Côte d’Ivoire). The main objective of this study was to ensure a sustainable productivity of cassava in the Daloa region by controlling termite’s pests of cassava crops according to the phenological stage, namely: the plot of cassava at the small stalk stage, the plot at the tuber production stage and the plot at the harvest stage. To this end, systematic excavations were carried out in the sections along the transects and plant-by-plant sampling in order to inventory the different species of termites on the plots and to highlight the damage they cause. This made it possible to identify 4 species of termites: Odontotermes sp., Macrotermes bellicosus, Pseudacanthotermes militaris and Nasutitermes latifrons, of which 1 species is common to all three environments. The comparative analysis of the different study environments showed that the plots at the production stage and at the harvest stage are the most colonized by termites. Odontotermes sp. observed only in plots at the small stage, as well as Nasutitermes latifrons which are only present on the plot at the production stage. Pseudacanthotermes militaris are best represented on all three plots.

Nitrate concentration and accumulation on vegetables related to altitude and sunlight intensity

Nitrate absorption and concentration in consumed vegetables should be also interrelated with its quality, where it is now less noticed in standard vegetable quality. The higher nitrate content is associated with the human health impact such as the baby blue syndrome and stimulating the tumor growth. The environmental status on especially sunlight intensity and quality has a special role to control nitrate concentration in the leaves. The purpose of this study was to characterize the nitrate concentration and accumulation in Brassica rapa L. grown in an open field and screen shading at lower and medium altitudes. Plant sampling was arranged at lower altitudes under 500 m asl (meters above sea level) and medium altitudes 500-700 m asl. Plant growth under shading and unshaded condition were observed for nitrate status as absorbed and its concentration in the sap plants. The study site at the lower altitude exposed sunlight intensity by 27.2% higher, where it decreased nitrate accumulation by 39.3%. Nitrate accumulation under shaded condition rate of 54.9% exhibited more 17.7% nitrate concentration in the vegetable.

Evaporative Flux Method of Leaf Hydraulic Conductance Estimation: Sources of Uncertainty and Reporting Format Recommendation

The accurate estimation of leaf hydraulic conductance (Kleaf) is important for revealing leaf physiology characteristics and function. However, there are some uncertain influencing factors in Kleaf measurement by using evaporation flux method (EFM), a widely used method. In this study, we investigated the potential impacts of plant sampling method, measurement setup, environmental factors, recording instrument, and transpiration steady status identification on Kleaf estimation. Our results indicated that the sampling and rehydration time, the small gravity pressure on leaf, and degassing treatment had limited effects on Kleaf values. Transpiration rate (E) was significantly affected by multiple environmental factors including airflow around leaf, light intensity, and leaf temperature. Kleaf values decreased by 40% from 1000 to 500 µmol m-2 s-1 light intensities and by 15.1% from 27 to 37 oC. In addition, the accurate flow rate (F) steady state identification and the leaf water potential measurement were important for Kleaf estimation. Based on the analysis of influencing factors, we provided a format for reporting the details of the EFM-based Kleaf measurement methods and metadata that future studies could interpret the results in method issue.

Quantifying wind plant blockage under stable atmospheric conditions

Wind plant blockage reduces the wind velocity upstream undermining turbine performance for the first row of the plant. We assess how atmospheric stability modifies the induction zone of a wind plant in flat terrain. We also explore different approaches to quantifying the magnitude and extent of the induction zone from field-like observations. To investigate the influence from atmospheric stability, we compare simulations of two stable boundary layers using the Weather Research and Forecasting model in large-eddy simulation mode, representing wind turbines using the generalized actuator disk approach. We find a faster cooling rate at the surface, which produces a stronger stably stratified boundary layer, amplifies the induction zone of both an isolated turbine and of a large wind plant. A statistical analysis on the hub-height wind speed field shows wind slowdowns only extend far upstream (up to 15D) of a wind plant in strong stable boundary layers. To evaluate different ways of measuring wind plant blockage from field-like observations, we consider various ways of estimating the freestream velocity upstream of the plant. Sampling a large area upstream is the most accurate approach to estimating the freestream conditions, and thus of measuring the blockage effect. Also, the choice of sampling method may induce errors of the same order as the velocity deficit in the induction zone.

GEO- AND PHYTO-MONITORING OF ENVIRONMENTAL IMPACT OF SMELTING INDUSTRY IN IKIRUN, NIGERIA

This research monitored the level of some heavy metals in soil and a plant species around iron smelting industry. The soil in different depths D1 (0 -10 cm), D2 (10 – 20 cm) and D3 (20 -30 cm) and plant (Tithonia diversifolia) known as Mexican sunflower were sampled in four soil sampling points (SSP) and plant sampling points (PSP) which are 50, 100, 150 and 200 m away from the industry. The concentrations of Cr, Cu, Fe, Pb and Zn in the soil and plant digest were determined using Atomic Absorption Spectroscopy (AAS). Some physicochemical properties like pH, electrical conductivity and organic matter were also measured. The result of the analysis of the heavy metals in the soil was in the sequence Fe > Zn > Cu >Pb> Cr at SSP1 SSP2 and SSP4 while Fe > Zn > Cu > Cr > Pb at SSP3. In the plant, the result showed the presence of these heavy metals except Pb which was not present in any sampling points. The concentration of iron (Fe) in the plant decreased away from PSP1 to PSP4 around the industry. The physicochemical properties like pH which influenced the availability of metals in soil were found to increase away from SSP1 to SSP4 and consequently its effect on the concentration of these heavy metals in plants, particularly for Fe and Zn. Although, heavy metals monitored were within the permissible limit of WHO except Fe in soil, the trend of their presence in

The SARSense Campaign: Air- and Space-Borne C- and L-Band SAR for the Analysis of Soil and Plant Parameters in Agriculture

With the upcoming L-band Synthetic Aperture Radar (SAR) satellite mission Radar Observing System for Europe L-band SAR (ROSE-L) and its integration into existing C-band satellite missions such as Sentinel-1, multi-frequency SAR observations with high temporal and spatial resolution will become available. The SARSense campaign was conducted between June and August 2019 to investigate the potential for estimating soil and plant parameters at the agricultural test site in Selhausen (Germany). It included C- and L-band air- and space-borne observations accompanied by extensive in situ soil and plant sampling as well as unmanned aerial system (UAS) based multispectral and thermal infrared measurements. In this regard, we introduce a new publicly available SAR data set and present the first analysis of C- and L-band co- and cross-polarized backscattering signals regarding their sensitivity to soil and plant parameters. Results indicate that a multi-frequency approach is relevant to disentangle soil and plant contributions to the SAR signal and to identify specific scattering mechanisms associated with the characteristics of different crop type, especially for root crops and cereals.

A Molecular Approach for Detecting Stage-Specific Predation on Lygus hesperus (Hemiptera: Miridae)

A molecular gut analysis technique is described to identify predators of Lygus hesperus (Knight), a significant pest of many crops. The technique is unique because it can pinpoint which life stage of the pest was consumed. Sentinel egg masses designed to mimic the endophytic egg-laying behavior of L. hesperus were marked with rabbit serum, while third instar and adult L. hesperus were marked with chicken and rat sera, respectively. Then, the variously labeled L. hesperus life stages were introduced into field cages that enclosed the native arthropod population inhabiting an individual cotton plant. After a 6-h exposure period, the predator assemblage, including the introduced and native L. hesperus population, in each cage were counted and had their gut contents examined for the presence of the variously marked L. hesperus life stages by a suite of serum-specific enzyme-linked immunosorbent assays (ELISA). The whole-plant sampling scheme revealed that Geocoris punticpes (Say) and Geocoris pallens Stal (Hemiptera: Geocoridae) and members of the spider complex were the numerically dominant predator taxa in the cotton field. The gut content analyses also showed that these two taxa appeared to be the most prolific predators of the L. hesperus nymph stage. Other key findings include that Collops vittatus (Say) (Coleoptera: Melyridae) and Solenopsis xyloni McCook (Hymenoptera: Formicidae) appear to be adept at finding and feeding on the cryptic L. hesperus egg stage, and that L. hesperus, albeit at low frequencies, engaged in cannibalism. The methods described here could be adapted for studying life stage-specific feeding preferences for a wide variety of arthropod taxa.

A multivariate approach to analyze the spatial-temporal variation of limnological parameters of the reservoir of the Curuá-Una hydroelectric plant

The construction of reservoirs for hydroelectric plants (HP) began in the 1960s and is currently an integral part of the objectives of economic expansion plans in Brazil. The Curuá-Una HP was the first HP constructed in the central Amazon. Due to the great importance of this reservoir for limnological studies in the Amazon, the objective of this study was to analyze and quantify the percentage of spatial-temporal variation of limnological variables upriver of the reservoir of the Curuá-Una hydroelectric plant. Sampling was conducted between 2016 and 2017. The limnological variables analyzed were water transparency, conductivity, turbidity, dissolved oxygen, pH, biological oxygen demand, nitrate, silica, total phosphorus, and chlorophyll-a. Principal components analysis was used to investigate patterns and the size of the gradient in the reservoir, and to select which spatial and temporal variables make significant contributions a canonical redundancy analysis (RDA) was conducted incorporating a partitioning of variance. PCA showed that the samples were seasonally grouped, and the first two axes explained 51.74% of the variability. The RDA and partition of variance showed that the spatial and temporal explanatory variables together explained 66% of the variability (time = 56%, spatial = 10%, time and spatial = 0%, residual = 34%). The results obtained suggest that the seasonal effect is responsible for 56% of the variability, and such changes in time are sufficient enough to alter the biological processes when environmental conditions are turbulent.

Physiological indexes of mini tomato cultivars grown in a protected environment

Shading screens are widely used to control excessive solar radiation, thereby changing plant growth. Thus, through physiological indices the objective was to evaluate the growth of three cultivars of minitomatoes under colored meshes. The experiment was conducted from April to July in the DTCS / UNEB experimental field in experiment DBC with subdivided plots, and four replicates, comprised of three shaded environments and the control treatment, three cultivars, and seven plant sampling seasons. For growth analysis, we used the destructive method, total dry matter was determined after drying it in an oven at 65°C. The total leaf area (LAI) was obtained using the software QUANT. Results showed that there was no interaction between environments and the other factors. Regarding leaf area index, cvs. Shani and Sweet Million stood out in all environments, whereas cv. Red Sugar had a similar behavior in all environments. Shani obtained the best indices in open sun environment and in the environment covered with red shading screen, and Sweet Million obtained the best index under gray shading screen. Red Sugar had the lowest LAI, and consequently, the lowest SLA and LAR. On the other hand, it showed the highest RPF, since it obtained the highest dry matter in leaves compared to the other cultivars. Cvs. Shani and Sweet Million showed the best: TAL, TCR, TCA and TCC.

Evaluation of particulate matter PM2.5 and PM10 ,(Case study: Khash cement company, Sistan and Baluchestan)

Introduction: One of the most important contaminants in the cement industry are environmental suspended particles (PM2.5 and PM10), which cause respiratory and pulmonary diseases in humans. Materials and methods: This descriptive - analytical study was carried out in 2016-2017 on the peripheral particulate matter of Khash cement plant. Sampling was performed at 8 environmental stations of Khash Cement Company in spring, summer, fall and winter. A total of 576 samples were sampled of peripheral particulate matter. Results: The amount of particulate matter was PM2.5 2.82 to 24.63 μg/m3, respectively. The highest PM2.5 content was obtained in spring (24.32±2.51 μg/m3). The lowest amount of particulate matter PM2.5 in different seasons were measured in substation (P<0.05). The amount of particulate matter was PM10 19.98 to 68.22 μg/m3, respectively. The highest PM10 content was obtained in autumn (64.92±3.76 μg/m3). The lowest amount of particulate matter PM10 in spring and summer were measured in substation (P<0.05), but the lowest amounts in the autumn at the entrance door and in winter was observed in wastewater treatment. Conclusion: In this study, the amount of PM2.5 and PM10 peripheral particulate matter in Cement Company was lower than WHO and USEPA standard. According to the results it can be stated that the suspended particles Khash Cement Company environment for human respiration were within acceptable limits.