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In this research, estimation potential of Aquacrop model under deficit irrigation and salinity conditions were evaluated for winter wheat grown under arid and semi-arid climates. Five different irrigation strategies and irrigation water salinity levels (0.5, 5, 7.5, 10, 15 dS m-1) were taken with the model to estimate deficit irrigation and salinity scenarios. Wheat grain yield, biomass production and canopy cover were simulated under deficit and salinity stresses. According to estimation of the model; the deficit irrigation with water reduction of more than 75 % of full irrigation was applied at growth stages of wheat, revealed the significant reduction in grain yield, biomass and canopy cover as compared with full irrigation practice. The increase in irrigation water salinity caused a significant decrease in grain yield and biomass value. It was compared to the 0.5 dS m-1 salinity level, a low value of 3% was obtained for the 5 dS m-1 salinity level. Yield loss of 7.5, 10 and 15 dS m-1 salinity levels were found to be 18.97%, 42.5% and 85.6% respectively. Also, increasing irrigation water depth in saline treatments resulted in increased grain and biomass yield. For sustainable water management in agriculture area, using simulation model such as Aquacrop is useful tolls to estimate effect of applied water depth and quality of irrigation water on crop yield. [ABSTRACT FROM AUTHOR]

In Turkey, the renewable water potential per capita is rapidly decreasing in response to the increasing population. Of the 234 billion m2 renewable water potential of our country, 41 billion m2 consists of groundwater and 193 billion m2 consists of rivers. One of the measures to be taken in order to protect renewable water resources in our country, which is not rich in water, is to try to minimize the damage to ground and surface waters caused by solid and liquid wastes that occur in animal shelters. This damage occurs especially with the washing of negatively charged nitrate in the fertilizer content by factors such as precipitation and the increase in the nitrate level of water resources. For the prevention and reduction of environmental problems arising from the said polycultural enterprises; Ecological evaluation of the transition to sustainable farming methods is one of the elements of urgency for the ecological sustainability of animal husbandry. In this study; the definition, scope and briefly the principles of sustainable agricultural methods for the management of nitrate pollution, which is one of the most important parameters that cause water pollution from agricultural production, are emphasized, the reasons for the transition to sustainable agricultural methods are explained, and the necessity and applicability of closely monitoring these developments in İzmir, which has a great potential in terms of animal existence, has been discussed on a basin basis. In addition, in terms of different animal production branches, the situation of animal manure management infrastructure together with plant production has been evaluated and some suggestions have been made with innovative strategies on the basis of basin that can be an example pilot. [ABSTRACT FROM AUTHOR]

Radiocesium in water, soil, and air represents a severe threat to human health and the environment. It either acts directly on living organisms from external sources, or it becomes incorporated through the food chain, or both. Plants are at the base of the food chain; it is therefore essential to understand the mechanisms of plants for cesium retention and uptake. In this review we summarize investigations about sources of stable and radioactive cesium in the environment and harmful effects caused by internal and external exposure of plants to radiocesium. Uptake of cesium into cells occurs through molecular mechanisms such as potassium and calcium transporters in the plasma membrane. In soil, bioavailability of cesium depends on the chemical composition of the soil and physical factors such as pH, temperature and tilling as well as on environmental factors such as soil microorganisms. Uptake of cesium occurs also from air through interception and absorption on leaves and from water through the whole submerged surface. We reviewed information about reducing cesium in the vegetation by loss processes, and we extracted transfer factors from the available literature and give an overview over the uptake capacities of 72 plants for cesium from the substratum to the biomass. Plants with high uptake potential could be used to remediate soil and water from radiocesium by accumulation and rhizofiltration. Inside plants, cesium distributes fast between the different plant organs and cells, but cesium in soil is extremely stable and remains for decades in the rhizosphere. Monitoring of contaminated soil therefore has to continue for many decades, and edible plants grown on such soil must continuously be monitored. [ABSTRACT FROM AUTHOR]

The primary objective of this review study was to determine the best irrigation and fertilizer scheduling practice in order to achieve maximum yield with maximum water and fertilizer use efficiency and highest nutrient uptake. It is found nutrient use efficiency could be as high as 90 per cent in fertigation as compared to 40 to 60 per cent in conventional methods. The amount of fertilizer lost through leaching can be as low as 10 per cent in fertigation whereas it is 50 per cent in the traditional system. It is observed that irrigation and fertigation scheduled at 75% ET and at 75% RDF, respectively could be a good alternate for saving water and nutrients with enhanced nutrient uptake, growth, yield and quality of crops. In this paper, the literature pertaining to the different aspects of fertigation and irrigation scheduling are reviewed. [ABSTRACT FROM AUTHOR]

We investigated the ability of the aquatic fern Azolla to take up ciprofloxacin (Cipro), as well as the effects of that antibiotic on the N-fixing process in plants grown in medium deprived (-N) or provided (+N) with nitrogen (N). Azolla was seen to accumulate Cipro at concentrations greater than 160 μg g −1 dry weight when cultivated in 3.05 mg Cipro l −1 , indicating it as a candidate for Cipro recovery from water. Although Cipro was not seen to interfere with the heterocyst/vegetative cell ratios, the antibiotic promoted changes with carbon and nitrogen metabolism in plants. Decreased photosynthesis and nitrogenase activity, and altered plant's amino acid profile, with decreases in cell N concentrations, were observed. The removal of N from the growth medium accentuated the deleterious effects of Cipro, resulting in lower photosynthesis, N-fixation, and assimilation rates, and increased hydrogen peroxide accumulation. Our results shown that Cipro may constrain the use of Azolla as a biofertilizer species due to its interference with nitrogen fixation processes. [ABSTRACT FROM AUTHOR]

Water stress in plants is a complex physiological response to the limited availability of water to a plant. To address the variability in crop water status in different production systems, precision irrigation has been developed and implemented. Reliable measurements or predictions of plant water stress are desirable for numerous agricultural, forestry, conservation, and land rehabilitation applications. However, in order to implement precision irrigation, this method requires accurate information about the crop water status, soil moisture content, and weather (e.g., wind speed and vapor pressure deficit). Various technologies, including remote- and ground-based sensors, were developed, and some of them are available for the measurement of plant water stress. The objective of this article is to review the use of near-infrared (NIR) sensors to measure water potential in different crops and plants. [ABSTRACT FROM AUTHOR]

Non-structural carbohydrates ( NSC) play a crucial role in tree resistance and resilience to drought. Stem sapwood parenchyma is among the largest storage tissue for NSC in mature trees. However, there is a limited mechanistic understanding of how NSC reserves, stem parenchyma abundance and growth rates are interrelated, and how they respond to changing water availability., We quantified NSC, ray parenchyma abundance and ring width along four successive 5-year radial sapwood segments of the stem of 40 mature Pinus sylvestris trees from a 10-year irrigation experiment conducted at a xeric site in Switzerland., Percentage of ray volume ( PERPAR) varied from 3·75 to 8·94% among trees, but showed low intra-individual variability. PERPAR responded positively to irrigation with a lag of several years, but was unrelated to % NSC. % NSC was lower in wider rings. However, wider rings still contained a larger NSC pool that was positively related to next year's ring growth., Our results suggest that stem ray parenchyma does not limit NSC storage capacity, but responds to long-term environmental drivers with years of delay. The observed carbon allocation patterns indicate a prioritization of storage over growth independent of growth conditions, likely as a mechanism to ensure long-term survival. Furthermore, NSC pool size proved to be a determinant for the inter-annual autocorrelation in tree-ring growth. Our study highlights the importance of long-term multi-parameter studies to better understand tree responses to environmental variability at different time-scales., A is available for this article. [ABSTRACT FROM AUTHOR]

Globally, it is estimated that 20 million hectares of arable land are irrigated with water that contains residual contributions from domestic liquids. This potentially poses risks to public health and ecosystems, especially due to heavy metals, which are considered dangerous because of their potential toxicity and persistence in the environment. The Villavicencio region (Colombia) is an equatorial area where rainfall (near 3000 mm/year) and temperature (average 25.6 ◦C) are high. Soil processes in tropical conditions are fast and react quickly to changing conditions. Soil properties from agricultural fields irrigated with river water polluted by a variety of sources were analysed and compared to non-irrigated control soils. In this study, no physico-chemical alterations were found that gave evidence of a change due to the constant use of river water that contained wastes. This fact may be associated with the climatic factors (temperature and precipitation), which contribute to fast degradation of organic matter and nutrient and contaminants (such as heavy metals) leaching, or to dilution of wastes by the river. [ABSTRACT FROM AUTHOR]

Field experiments were conducted at the Tamil Nadu Agricultural University, Coimbatore, Tamilnadu, India during kharif and rabi season of 2014 with maize crop (TNAU maize hybrid Co 6). To ensure the stressed environment, the crop was subjected to two irrigation levels (IW/CPE: 0.80 and 0.50) and five staggered nitrogen levels (0, 50, 75, 100 and 125 per cent of recommended dose of nitrogen (RDN). The experiment was laid out in randomized blocks design RBD (Factorial) with three replications. A higher value of spectral vegetation indices viz., NDVI, GNDVI, RVI, LCI, IR-RED and SR were recorded with irrigation at IW/CPE ratio 0.80 either with 100 or 125 per cent RDN (unstressed) applied to maize crop. Maize under stressed environment recorded reduced values of spectral vegetation indices when the crop was irrigated at 0.50 IW/CPE ratio with no nitrogen. All the spectral vegetation indices expressed positive correlation (highly significant at 1 per cent probability level) with crop parameters. The overall best fit was linear with a regression coefficient between vegetation indices (GNDVI, NDVI) and with crop parameters, and actual grain yield and predicted yield (0.81 to 0.85) of maize. The ability of spectral vegetation indices to quantify the combined effect of nitrogen and water stress on maize too early through remote sensing paves the way for large scale application of satellite remote sensing. [ABSTRACT FROM AUTHOR]

In a climate change scenario, successful modeling of the relationships between plant-soil-meteorology is crucial for a sustainable agricultural production, especially for perennial crops. Grapevines (Vitis vinifera L. cv Chardonnay) located in eight experimental plots (Burgundy, France) along a hillslope were monitored weekly for 3 years for leaf water potentials, both at predawn (ψpd) and at midday (ψstem). The water stress experienced by grapevine was modeled as a function of meteorological data (minimum and maximum temperature, rainfall) and soil characteristics (soil texture, gravel content, slope) by a gradient boosting machine. Model performance was assessed by comparison with carbon isotope discrimination (δ13C) of grape sugars at harvest and by the use of a test-set. The developed models reached outstanding prediction performance (RMSE < 0.08 MPa for ψstem and < 0.06 MPa for ψpd), comparable to measurement accuracy. Model predictions at a daily time step improved correlation with d13C data, respect to the observed trend at a weekly time scale. The role of each predictor in these models was described in order to understand how temperature, rainfall, soil texture, gravel content and slope affect the grapevine water status in the studied context. This work proposes a straight-forward strategy to simulate plant water stress in field condition, at a local scale; to investigate ecological relationships in the vineyard and adapt cultural practices to future conditions. [ABSTRACT FROM AUTHOR]

Ammonia volatilization is an important nitrogen (N) loss pathway in agricultural production and consequent significant atmospheric pollutant. The primary objective of this study was to (1) examine effects of environmental factors such as temperature and soil water capacity, as well as crop residue (CR) addition as fertilizer, on ammonia (NH3) volatilization, and (2) search for a comprehensive management strategy to reduce accumulative ammonia volatilization (AAV). A bench-scale cultivated experiment was conducted at two environment temperatures (15 or 25 °C), three forms of soil water capacity (30%, 50%, or 70% soil field moisture capacity), and two treatments of fertilizers (conventional fertilizer urea and straw returning – 10% of total N application arising from maize straw and remainder from conventional urea). Results showed that AAV was markedly decreased by adjusting soil water capacity, temperature, and CR addition. Significant quantified exponential correlation between AAV and soil moisture was observed. More than 70% AAV was reduced in intermediate 50% and high 70% soil moisture compared to low 30%. AAV was less sensitive to temperature than soil moisture using black soils. Only in low soil moisture, AAV rose with increasing of temperature. Straw restoration addition decreased significantly the AAV loss. [ABSTRACT FROM PUBLISHER]

Tree water uptake relies on well-developed root systems. However, mine wastes can restrict root growth, in particular metalliferous mill tailings, which consist of the finely crushed ore that remains after valuable metals are removed. Thus, water stress could limit plantation success in reclaimed mine lands. This study evaluates the effect of substrates varying in quality (topsoil, overburden, compost and tailings mixture, and tailings alone) and quantity (50- or 20-cm-thick topsoil layer vs. 1-m² plantation holes) on root development and water stress exposure of trees planted in low-sulfide mine tailings under boreal conditions. A field experiment was conducted over 2 yr with two tree species: basket willow (Salix viminalis L.) and hybrid poplar (Populus canadensis Moench × Populus maximowiczii A. Henry). Trees developed roots in the tailings underlying the soil treatments despite tailings' low macroporosity. However, almost no root development occurred in tailings underlying a compost and tailings mixture. Because root development and associated water uptake was not limited to the soil, soil volume influenced neither short-term (water potential and instantaneous transpiration) nor long-term (δ13C) water stress exposure in trees. However, trees were larger and had greater total leaf area when grown in thicker topsoil. Despite a volumetric water content that always remained above permanent wilting point in the tailings colonized by tree roots, measured foliar water potentials at midday were lower than drought thresholds reported for both tested tree species. [ABSTRACT FROM AUTHOR]

Plants are often subjected to periods of water stress. There are little data examining the effect of water stress on the forage species Plantago lanceolata and Cichorium intybus. In two pot experiments with P. lanceolata and C. intybus, morphological responses under optimum, dry, and very-dry water treatments with weekly, fortnightly and 3-weekly defoliation intervals and physiological responses under optimum and very-dry water treatments were measured. A third experiment compared the rooting depths of P. lanceolata and C. intybus under field conditions. These findings suggest that both P. lanceolata and C. intybus can survive and continue to grow under water stress conditions with the main differences between the two species being attributable to morphological characteristics (root mass, taproot diameter and shoot mass fraction) rather than differences at a physiological level. Overall, the results suggest plantain may be more productive under moderate drought due to its greater shoot mass fraction, whereas chicory may be more productive and persistent under severe drought due to its greater root mass, taproot diameter and root depth under field conditions. [ABSTRACT FROM AUTHOR]

The environment is the largest component of the phenotypic variance of crop yield, hence the importance of its quantitative characterisation. Many studies focussed on the patterns of water deficit for specific crops and regions, but concurrent water and thermal characterisations have not been reported. To quantify the types, spatial patterns, frequency and distribution of both water stress and thermal regimes for chickpea in Australia, we combined trial and modelled data. Data from National Variety Trials including sowing time, yield and weather from 295 production environments were entered into simulations. Associations between actual yield, in a range from 0.2 to 5.2 t/ha, actual temperature and modelled crop water stress were explored. Yield correlated positively with minimum temperature in the 800 degree-days window bracketing flowering and the correlation shifted to negative after flowering. A negative correlation between maximum temperature over 30°C and yield was found from flowering through to 1000 degree-days after flowering. Yield was negatively correlated with simulated water stress from flowering until 800 degree-days after flowering. Cluster analysis from 3905 environments (71 locations×55 years between 1958 and 2013) identified three dominant patterns for both maximum and minimum temperature accounting for 77% and 61% of the overall variation, and four dominant patterns for water stress accounting for 87% of total variation. The most frequent environments for minimum and maximum temperature were associated with low actual yield (1.5-1.8 t/ha) whereas the most frequent water-stress environment was associated with the second lowest actual yield (1.75 t/ha). For all temperature and water-stress types, we found significant spatial variation that is relevant to the allocation of effort in breeding programs. [ABSTRACT FROM AUTHOR]

Thermal imaging can detect variation in stomatal conductance and therefore spatial variation in the water status of grapevine. Temporal variation can also be assessed, using indices that relate canopy temperature to reference temperatures, but, as yet, there is no standard approach to obtain these reference values. Also, the potential of above-canopy imaging is uncertain for vine rows with mainly vertically oriented leaves. Thermal images of the side (vertical leaves) and top (horizontal leaves) of 'Tempranillo' (Vitis vinifera L.) grapevine rows were captured on different dates and in different plots in a vineyard in the Rioja, Spain. Reference temperatures were determined separately (i) as the temperature of artificial leaves placed in the grapevine canopy, or (ii) by calculation from the leaf energy budget. With respect to imaging the side of grapevine rows, the two approaches exhibited similar potential to indicate variation in stomatal conductance or stem water potential within a single date and time of day. Over different dates (implying temporal as well as spatial variability) and both sides of the grapevines, the use of the artificial surfaces resulted in stronger correlations between thermal indices and physiological variables than the application of energy budget models. The use of such reference surfaces would allow a standardised approach to thermography. Imaging the top of rows produced some highly significant correlations between thermal indices and physiological variables. Modified artificial leaves could be developed to standardise the determination of reference temperatures, at the same spatial resolution as the leaves of interest. That imaging the top of grapevine canopies provides useful information on water status suggests that aerial imaging could be used to assess spatial variation in water status across entire vineyards. [ABSTRACT FROM AUTHOR]

* Premise of the study: Temperature and water potential for germination based on the thermal and hydrotime models have been successfully applied in predicting germination requirements of physiologically dormant seeds as well as nondormant seeds. However, comparative studies of the germination requirements of physically dormant seeds from different ecosystems have not been done. * Methods: Germination of scarified seeds of four legume species collected from the Qing-Tibetan Plateau and of four collected in the Alax Desert in China was compared over a range of temperatures and water potentials based on thermal time and hydrotime models. * Key results: Seeds of species from the Qing-Tibetan Plateau had a lower base temperature (Tb) and optimal temperature (To) for germination than those from the Alax Desert. Seeds of the four species from the Qing-Tibetan Plateau germinated to high percentages at 5°C, whereas none of the four desert species did so. Seeds of species from the Alax Desert germinated to a high percentage at 35°C or 40°C, while no seeds of species from the Qing-Tibetan Plateau germinated at 35°C or 40°C. The base median water potential [Ψb(50)] differed among species but not between the two habitats. * Conclusions: The thermal time and hydrotime models accurately predicted the germination time course of scarified seeds of most of the eight species in response to temperature and water potential; thus, they can be useful tools in comparative studies on germination of seeds with physical dormancy. Habitat temperatures but not rainfall is closely related to germination requirements of these species. [ABSTRACT FROM AUTHOR]

Romanian agriculture current realities indicates that organized societies with modern equipment and staffed with specialists represent only 20% of the actors in the production, the remaining of 80% being producers with different levels of equipment and staffing specialist. Therefore there are real risks that the inputs used in agriculture (fertilizers, pesticides, etc.) have negative secondary effects (DUMITRU, 2002) through soil and water pollution (GAVRILESCU, 2011). Increased content of nitrates and nitrites in soil and water has become a major factor affecting the health of the population, both rural and urban, and especially children, but in a broader context the entire population consuming water, vegetables fruit from out of control locations (nitrates vulnerable zones) (NAZARYUK et al., 2002). This paper presents the case of illness in children internees at No. 1 Hospital from Craiova for a period of 5 years. One can observe that most cases come from rural areas, 76%, with children aged less than one year and over five years, by introducing in their diet milk powder, tea, soup of carrots and other vegetables that are high in nitrates. Cases have been reported in some villages that were connected to the water system of the village and which were infested with toxic substances. In urban areas the percentage is 24% of illness, it is strongly recommended for measures to limit the content of toxic substances in groundwater and surface water. [ABSTRACT FROM AUTHOR]

Highlights: [•] Trunk growth rate measurements were similar in the branch than in the trunk locations. [•] Maximum daily shrinkage was similar in branch than in trunk in no water stress trees. [•] The influence of crown volume on indices derived from trunk diameter records was low. [•] Point and band dendrometers measurements did not fit with the expected equation. [Copyright &y& Elsevier]

Chlorophyll a fluorescence is established as a rapid, non-intrusive technique to monitor photosynthetic performance of plants and algae, as well as to analyze their protective responses. Apart from its utility in determining the physiological status of photosynthesizers in the natural environment, chlorophyll a fluorescence-based methods are applied in ecophysiological and toxicological studies to examine the effect of environmental changes and pollutants on plants and algae (microalgae and seaweeds). Pollutants or environmental changes cause alteration of the photosynthetic capacity which could be evaluated by fluorescence kinetics. Hence, evaluating key fluorescence parameters and assessing photosynthetic performances would provide an insight regarding the probable causes of changes in photosynthetic performances. This technique quintessentially provides non-invasive determination of changes in the photosynthetic apparatus prior to the appearance of visible damage. It is reliable, economically feasible, time-saving, highly sensitive, versatile, accurate, non-invasive and portable; thereby comprising an excellent alternative for detecting pollution. The present review demonstrates the applicability of chlorophyll a fluorescence in determining photochemical responses of algae exposed to environmental toxicants (such as toxic metals and herbicides). [Copyright &y& Elsevier]

The impact of moderate water deficit on the photosynthetic apparatus of three Phaseolus vulgaris L. cultivars, Plovdiv 10 (P10), Dobrudjanski Ran ( DR) and Prelom ( Prel), was investigated. Water shortage had less impact on leaf hydration, RWC (predawn and midday) and predawn water potential in Prel. RWC and Ψp were more reduced in P10, while there was no osmotic adjustment in any cultivar. Although drought drastically reduced stomatal opening in P10 and DR, reduced Amax indicated non-stomatal limitations that contributed to the negligible Pn. These limitations were on potential thylakoid electron transport rates of PSI and II, pointing to photosystem functioning as a major limiting step in photosynthesis. This agrees with decreases in actual photochemical efficiency of PSII (Fv′/Fm′), quantum yield of photosynthetic non-cyclic electron transport (ϕe) and energy-driven photochemical events (qP), although the impact on these parameters would also include down-regulation processes. When compared to DR, Prel retained a higher functional state of the photosynthetic machinery, justifying reduced need for photoprotective mechanisms (non-photochemical quenching, zeaxanthin, lutein, β-carotene) and maintenance of the balance between energy capture and dissipative pigments. The highest increases in fructose, glucose, arabinose and sorbitol in Prel might be related to tolerance to a lower oxidative state. All cultivars had reduced Amax due to daytime stomatal closure in well-watered conditions. Under moderate drought, Prel had highest tolerance, higher leaf hydration and maintenance of important photochemical use of energy. However, water shortage caused appreciable non-stomatal limitations to photosynthesis linked to regulation/imbalance at the metabolic level (and growth) in all cultivars. This included damage, as reflected in decreased potential photosystem functioning, pointing to higher sensitivity of photosynthesis to drought than is commonly assumed. [ABSTRACT FROM AUTHOR]

The aim of the study was to use bioassays to evaluate the toxicity of pore water, sediments and sediments elutriates. Furthermore, a possible relationship between observed toxicity and results of chemical analysis was examined. Sediment (0–10cm) samples were collected from 21 locations in Zeslawice reservoir, Southern Poland using an Ekman sampler. Toxicity assessment of the sediment and pore water samples was performed using direct-contact tests Phytotoxkit/Phytotestkit and Microtox®. Inhibition of seed germination in the test plants was from −25 to 38 percent for sediment and from 0 to 50 percent for pore water, whereas inhibition of root growth was within a range from −42 to 37 percent for sediment and from −49 to 37 percent for pore water. Depending on the sediments, Vibrio fischeri luminescence inhibition was from −18 to 40 percent for sediments elutriates and from −12 to 28 percent for pore water. The toxicity tests showed a positive correlation between metals and the root growth inhibition in Lepidium sativum and Sinapis alba as well as the luminescence inhibition in V. fischeri. No significant correlations were found between the inhibition of luminescence and the phytotoxicity assays, so these analyses do not show a similar sensitivity to toxicants in the sediments. While estimating the sensitivity of the performed biotests, the highest number of toxic responses was recorded in the Microtox® test towards V. fischeri. Among the plant species, Sorghum saccharatum appears to be the most sensitive plant species. Most of the examined sediment samples (67 percent) were classified as class II (low-toxic samples, low acute hazard) and 33 percent of the examined samples were class I (no essential toxic effect, non-toxic sample, no acute hazard) in terms of toxicity. Most of the pore water samples (71 percent) were also classified as class II. [Copyright &y& Elsevier]

Dechloranes (Decs), including Dechlorane Plus (DP) and Dechlorane (Dec) 602, 603, 604, are used as flame retardants. Fifty four samples were collected in a river in northeastern China and analyzed for Decs by gas chromatography/mass spectrometry. The average concentrations of total DP (syn- and anti-) in water, sediment, air, reed (Phragmites australis), and fish (E. elongatus) were 0.30±0.24 (mean±SD) ngL−1, 1.3±0.69ngg−1 dry weight (dw), 0.25±0.18ngm−3, 0.63±0.18ngg−1 wet weight (ww), and 29±20ngg−1 lipid weight (lw), respectively. While Dec 602 and Dec 603 were detected in most of sediment and fish samples, no Dec 604 was found in any of the investigated environmental matrices. The mean ratio of syn-DP to total DP (f syn ) in water, sediment, reed, and fish were 0.28, 0.25, 0.27 and 0.47, suggesting depletion in abiota and enrichment in biota for syn-DP. It was found that biota-sediment accumulation factor (BSAF) was 4.7 for Dec 602, 0.88 for syn-DP, and 0.33 for anti-DP. [Copyright &y& Elsevier]

The objectives of this experimental study were to examine the interaction between metal contaminated aquatic environments and element uptake by Echinodorus amazinocus and Cryptocoryne undulata. Changes in element concentrations were investigated in three phases in aquatic environments: water, pore water and sediment. Additionally, the amounts of partial elements, relative uptakes, translocation factor and bio-concentration factor were evaluated for each plant. Growth analyses of both plants, as well as physical parameters of the water quality obtained from the reactors, were statistically evaluated by a two-sample t-test. Following the analyses, it was observed that the amount of all of the elements in each of the phases was different for each intermittent sample. Studies with C. undulata and E. amazinocus demonstrated that the concentration of all of the elements in the plants was changing relatively. It was also found that existing environmental conditions did not affect plant life negatively. [Copyright &y& Elsevier]

Few studies have examined the effects of clonal integration (translocation of resources between interconnected ramets) during the expansion of amphibious clonal plants from terrestrial to aquatic habitats. We conducted a greenhouse experiment to simulate the expansion of plants from terrestrial to contaminated aquatic habitats in the amphibious stoloniferous herb Alternanthera philoxeroides (alligator weed). The proximal ramets (i.e. relatively old) of clonal fragments grown in uncontaminated soils were connected to (allowing clonal integration) or disconnected from (preventing clonal integration) distal ramets (i.e. relatively young) grown either in uncontaminated water (control, no CuSO4) or in four copper-contaminated water treatments containing 31.25, 62.5, 125 and 250 mg/L CuSO4, respectively. When a stolon connection was severed, all distal ramets grown in the contaminated water died. When the stolon connection was intact, however, the survival rate of the distal ramets was 85-100% when they were grown at the three lower levels of contamination and 43.75% at the highest level. Moreover, the survival rate and growth of the distal ramets grown in the three lower levels of contamination treatments did not differ from those in the control (uncontaminated water). These results suggest that clonal integration could greatly improve the survival and growth of alligator weed subjected to moderate levels of copper stress. Although clonal integration could also increase the survival rate of the connected distal ramets subjected to the highest level of copper stress (250 mg/L CuSO4) compared with that of disconnected distal ramets, the survival rate and growth measures were still significantly lower than those in the control. This suggests that clonal integration plays a limited role in the survival and growth of alligator weed when it is subjected to severe stress by high levels of copper contamination. [ABSTRACT FROM AUTHOR]

This paper investigates the effects of a finite-size vegetation patch on flow turbulence, variations in drag forces experienced by individual plants within the patch, and flow-drag interrelations. The experiments were conducted in a 32 m long laboratory flume with a 2.8 m long artificial patch. The plants were arranged to form a staggered pattern and three flow scenarios were tested. Velocities were recorded with an acoustic doppler velocimeter, whereas specifically designed devices were used to simultaneously measure the drag forces acting on nine plants within the patch. For all studied cases, the results show zones of increased turbulent energy close to the leading edge and along the patch canopy top, where turbulence shear production is enhanced. Zones of negative Reynolds stresses -u'w' are found inside the patch and they reflect the influence of plant morphology, which affects the shape of the longitudinal velocity profile and associated turbulent fluxes. Modifications to the power spectral densities of velocity by the plants indicate the emergence of two plant-induced mechanisms of energy production, which are most likely related to the wake turbulence and shear layer turbulence. Drag fluctuations appear to be correlated with the velocity field, with this correlation being especially profound at the highest-studied flow rate. The data suggest that the highlighted correlation stems from flow-plant interactions at the top of the vegetation canopy, likely due to the presence of large three-dimensional coherent structures. [ABSTRACT FROM AUTHOR]

The objective of this research was to identify genotypes tolerant to stress caused by NaCl and the mixture of NaCl, CaCl2 and MgCl2 in irrigation water in the early stages of development. The levels of electrical conductivity of saturation extract were 0, 0.25, 5.0 and 7.5dS m-1. The tolerance of cowpea was evaluated by the relative reduction in shoot dry matter of each genotype. The genotype CE-182 had more tolerant levels of 2.5, 5.0 and 7.5dS m-1 in saline water with NaCl. In the solution mixture of salts, the genotypes and CE-9 and CE-551 were the most tolerant. According to the results obtained by clustering using the UPGMA method it can verified that the most promising combinations for crosses which obtained superior progenies in the development of cultivars tolerant to salinity were found between genotypes CE-182 and CE-250 and between CE-551 and CE-9. [ABSTRACT FROM AUTHOR]

Abstract: Egeria densa has ability to grow in heavy metal contaminated and polluted bodies of water. Shoots exposed to Cd at concentrations up to 300μM for 7 days showed a pronounced decrease in chlorophyll a and in total protein concentration. Thiol-containing compounds and low-molecular-weight polypeptides were detected in Cd-treated plant extracts by gel filtration chromatography. Two Cd-binding fractions, a thiol-enriched fraction and a non-thiol fraction with a lower molecular weight were identified in extracts by gel filtration. The main fraction of thiol-containing polypeptide, purified by gel filtration and anion-exchange chromatography had a molecular weight of ∼10kDa. This peptide was characterized by a broad absorption band specific to mercaptide bonds and Cd-sensitive fluorescence emission of aromatic amino acid residues. Our results indicate that cadmium exposure of plants resulted in both a formation of thiol-enriched cadmium complexing peptides and a synthesis of low-molecular-weight metal chelators. The putative role of these compounds in Cd detoxification is discussed. [Copyright &y& Elsevier]

The effect of light and water on aromatic rice remain largely unclear. A pot experiment was conducted to investigate the influences of light-water treatments (CK: natural light and well-watered conditions, WS: natural light and water-stressed conditions, LL: low light and well-watered conditions, LL-WS: low light and water-stressed treatment) on yield and 2-acetyl-1-pyrroline (2AP) formation in aromatic rice. Compared with CK, the light-water treatments decreased grain yield (10.32–39.19%) due to reductions in the filled grain percentage and total dry weight, in the regulation of biomass distribution, and in the attributes of gas exchange and antioxidant response parameters. The 2AP content in grains increased in the LL treatment (5.08–16.32%) but decreased in the WS treatment compared with that in CK. The changes in 2AP were associated with changes in 2AP formation-related traits and element content. Low light and water stress led to yield declines in aromatic rice, but low light alleviated the decrease in 2AP content caused by water stress. [ABSTRACT FROM AUTHOR]

The article discusses the method of growing African violets. Topics discussed include selecting the varieties looking for easy-to-manage foliage, selecting a potting mix which is the use of a 1-1-1 mix, and having the mix and water in the correct pH range and checking the pH of the water that runs through a pot.

Aquatic plants are vital to the life of many species that live in lakes, rivers, ponds, and streams. According to recent studies, aquatic plants such as duckweed take in many pollutants in these water sources faster than bacteria can degrade them. To determine the effect of water pollution on aquatic plants, the growth of aquatic plants in different types of water was studied. Nine groups of duckweed from Maumee Bay State Park were collected and grown in three different types of water at room temperature: Maumee River water, tap water, and chlorinated water (containing eight times the chlorine of tap water). Diameter, area, water, and air temperature were recorded on three different days. Total growth was determined by measuring the diameter of the group then calculating the area. The duckweed did not grow in chlorinated water, but grew equally well in tap water and in Maumee River water. In conclusion, this experiment was designed to discover if aquatic plants can be an indicator for water pollution. The investigation did not show a definite answer to this question. If this experiment was to be revisited, a change in the hypothesis would take place because aquatic plants can adapt to water with varying qualities. The experiment may reveal different and more definite results if it was re-done. The duration of the experiment should be extended for further research. Some pollutants could possibly extend the life of aquatic plants because they have the ability to take in water pollutants faster than bacteria can degrade them. [ABSTRACT FROM AUTHOR]