Simulated Summertime Regional Ground-Level Ozone Concentrations over Greece

Ground-level ozone concentrations were estimated for Greece during a summer period of the year 2000 using the regional air quality model UAM-V off-line coupled with the mesoscale meteorological model MM5. An anthropogenic NOx, NMVOCs and CO emission inventory and biogenic NMVOCs emission data were used to support model simulations. The evaluation analysis indicates a quite satisfactory model performance in reproducing ozone levels. The simulated mean ozone concentrations are above the 32-ppb EU phytotoxicity limit over almost all continental and maritime areas of Greece. Over the greater part of the country, the background mean ozone levels range from 40 to 55 ppb. Ozone values higher than the 55-ppb EU human health protection limit reaching 60 ppb dominate part of the southern Aegean Sea that is influenced by the Athens urban plume. In the areas where anthropogenic emission densities are high, the mean ozone levels vary between 20 and 40 ppb. Over the greater part of Greece, the simulated mean daily maximum ozone concentrations range from 50 to 65 ppb. More enhanced maximum ozone concentrations up to 95 ppb mainly dominate over the greater areas of the two largest Greek urban centres (Athens and Thessaloniki) and over the continental and maritime areas south of Athens which are under the influence of the urban plume.     

Efficacy of grain protectants against four psocid species on maize,rice and wheat

BACKGROUND: Psocids are emerging pests in stored products, particularly in amylaceous commodities such as grains. Currently, their control is based on the use of fumigants and contact insecticides; however, newer data indicate that psocids are tolerant to insecticides used to control other stored‐grain species. This study evaluated the insecticides registered in the USA for use on stored maize, rice and wheat for control of the psocid species Lepinotus reticulatus, Liposcelis entomophila, L. bostrychophila and L. paeta. Mortality of exposed adult females was recorded after 7 and 14 days of exposure, while progeny production was assessed after 30 days of exposure. RESULTS: On wheat and rice, chlorpyriphos‐methyl + deltamethrin was generally more effective against exposed parental adults than spinosad or pyrethrin, while pirimiphos‐methyl was more effective on maize than spinosad or pyrethrin. In most cases, progeny production was suppressed in the treated grains. Progeny production was consistently lowest on wheat and rice treated with chlorpyriphos‐methyl + deltamethrin and maize treated with pirimiphos‐methyl. CONCLUSIONS: Chlorpyriphos‐methyl + deltamethrin and pirimiphos‐methyl were the most effective insecticides for all species and commodities. Conversely, efficacy of spinosad or pyrethrum was highly dependent on the psocid species and commodity. Published in 2009 by John Wiley & Sons, Ltd.     

The effect of genetic variation and nitrogen fertilization on productive characters of Greek oregano

This study aims to investigate the response of 10 Greek Oregano (Origanum vulgare subsp. hirtum) populations, collected across Greece, under 3 levels of N-fertilization during 2012 and 2013. The populations were differentiated for dry matter (from 32.7 to 63.3?g·pot^?1), for essential oil content (from 2.31 to 5.86?ml·100^?1?g dry weight) and for amount of essential oil (from 1.37 to 2.46?ml·pot^?1), for both years. Those with the highest dry matter (1-“Palaiochori” and 5-“Gliki”) and the highest essential oil content (10-“Gytheio” and 9-“Achladocastro”) were superior by 30%, as compared to the general mean of the experiment. The populations 3-“Litochoro” and 5-“Gliki” had an increased amount of essential oil (24%) as compared to the general mean of the experiment. An additional nitrogen supply (N₀ to N₁ level) increased dry matter production and amount of essential oil per pot, while decreased essential oil content for all populations. Further increase of nitrogen supply, favored six populations for dry matter production and two populations for amount of essential oil per pot while had almost no effect on five populations for essential oil content. The superior populations could be used in a breeding program as starting material for the development of new cultivars.     

THE 4C APPROACH AS A WAY TO UNDERSTAND SPECIES INTERACTIONS DETERMINING INTERCROPPING PRODUCTIVITY

● The 4C approach considers intercropping performances as the result of joint 4C effects. ● Partial land equivalent ratios indicate which effect(s) are the major one(s). ● A major effect of complementarity is related to a better capture of abiotic resources. Modern agriculture needs to develop transition pathways toward agroecological, resilient and sustainable farming systems. One key pathway for such agroecological intensification is the diversification of cropping systems using intercropping and notably cereal-grain legume mixtures. Such mixtures or intercrops have the potential to increase and stabilize yields and improve cereal grain protein concentration in comparison to sole crops. Species mixtures are complex and the 4C approach is both a pedagogical and scientific way to represent the combination of four joint effects of Competition, Complementarity, Cooperation, and Compensation as processes or effects occurring simultaneously and dynamically between species over the whole cropping cycle. Competition is when plants have fairly similar requirements for abiotic resources in space and time, the result of all processes that occur when one species has a greater ability to use limiting resources (e.g., nutrients, water, space, light) than others. Complementarity is when plants grown together have different requirements for abiotic resources in space, time or form. Cooperation is when the modification of the environment by one species is beneficial to the other(s). Compensation is when the failure of one species is compensated by the other(s) because they differ in their sensitivity to abiotic stress. The 4C approach allows to assess the performance of arable intercropping versus classical sole cropping through understanding the use of abiotic resources.     

Environmental parameters affecting the species diversity along the Aliakmon River, North Greece

The annual distribution of aquatic and coastal macrophytes in five selected sites along the Aliakmon River was studied from January 2005 to December 2005 in Northern Greece. Soil and water chemical parameters in these sites were also evaluated. A total of 75 taxa were recorded belonging to 37 families and 53 genera. The majority of the macrophytes belonged to coastal plants (76%), whereas the rest of the macrophytes belonged to aquatic plants (24%). Species of the family Asteraceae were dominant among coastal plants, whereas species of the family Potamogetonaceae were dominant among aquatic plants. Soil samples from the site of Dam of Veria had higher pH and electric conductivity (80-100 cm depth), whereas CaCO3 contents were significantly higher in soil samples from the area of P. Prodromos (60-80 cm depth). Most physicochemical water parameters as well as selected soil nutrients and major ionic components showed an increase during the low charge period (fall) compared to with the high charge period (spring), especially in parameters associated with agricultural activity. Furthermore, there was an increase in most examined values moving towards the delta of the river.     

Mussel farming impacts on trophic status and benthic community structure in Maliakos Gulf (Eastern Mediterranean)

The impact of shellfish farming on the water column nutrient concentration and the benthic community structure was investigated seasonally at a mussel farm (Mytilus galloprovincialis L.) of Maliakos Gulf (Eastern Mediterranean). In most cases concentration of nutrients and chl a at the farm site was lower than those observed at the control sites. Statistical analysis in concentration of all nutrients and chl a indicated significant interactions between sites and seasons, which in all cases were temporal. Furthermore, no significant interactions were found between sites and seasons for all sediment and benthic community parameters, except for Shannon–Wiener diversity index and species richness. The significant interactions detected in the biotic data were temporal. Analysis of similarity and similarity percentages analysis revealed a certain fluctuation of benthic macrofaunal community during the overall sampling year mainly due to temporal rather than spatial effects. Cluster analysis and multidimensional scaling ordination plot indicated the clearly separation of the farm site and the control sites in most of the seasons. K-dominance curves showed small difference in elevation and overlap indicating minimal difference in biological stress between the farm site and the control sites. All the above indicates that probably the farming of mussels was beneficial for the trophic status of Maliakos Gulf and that there was a minimal environmental stress caused by the shellfish farming for the surrounding benthic environment.     

Fisher's preferences and trade‐offs between management options

Failure to understand the potential responses of fishers to management measures creates a significant risk of revisiting the familiar scenario of perverse and unintended consequences of those measures. This paper reports on a choice experiment survey to evaluate fisher's preferences for various management measures proposed under the EU Common Fisheries Policy (CFP) reform process, but the conclusions have wider relevance as similar measures are used by comparable fleets in fisheries globally. The survey was conducted with fishers involved in mixed pelagic and demersal fisheries in Ireland, pelagic fisheries in Denmark and demersal fisheries in Greece. Fisheries management policies were characterized by five attributes designed both to cover the principal CFP reform proposals and to integrate ecological, social, economic and institutional factors affecting fisher's decisions. The study uses a random utility modelling framework to reveal the preferences of the fishers across the alternative policy attributes. Results show that while there are generally preferences both for healthy stocks and for maintaining the importance of fishing to the local community, strong interfishery preference differences exist. These differences are most notable in relation to a discard ban and to the use of individual transferable fishing rights, favoured in Denmark, but not in Ireland for instance. The strength of these interfishery differences supports the assertion that there are no panaceas in fisheries management and that solutions should be tailored within the context of specific fisheries. Not doing so could create a significant risk of inappropriately managed fisheries that may lead to unsustainable outcomes.     

Pyrithiobac reduces control of green foxtail (Setaria viridis) and bristly foxtail (Setaria verticillata) by propaquizafop

Experiments were conducted to evaluate potential interactions between propaquizafop and pyrithiobac applied in mixture or in sequential applications on green foxtail (Setaria viridis) and bristly foxtail (Setaria verticillata). The effect of propaquizafop application rate and the effect of ammonium sulphate were also evaluated. Propaquizafop (75–150 g ai/ha) applied alone at the five- to six-leaf growth stage provided 86–99% control of green foxtail and 92–100% control of bristly foxtail. Mixtures of propaquizafop with pyrithiobac applied at the same growth stage provided lower control of green foxtail and bristly foxtail by 27–33% and 17–22%, respectively, compared with propaquizafop applied alone. Increased rates of propaquizafop in the mixtures or the addition of ammonium sulphate did not eliminate the observed reduced control of both species with the mixture of pyrithiobac. Sequential applications where pyrithiobac was applied three days or one day before the application of propaquizafop also showed lower control of both species compared with propaquizafop applied alone. However, sequential applications where pyrithiobac was applied three days or one day after the application of propaquizafop showed more effective control of both species compared with the mixture and equal control to that achieved with propaquizafop applied alone.     

Effects of High Boron Concentration and Scion-Rootstock Combination on Growth and Nutritional Status of Olive Plants

Own rooted olive plants (Olea europaea L.) of the cvs. ‘Megaritiki’ (M), ‘Chondrolia Chalkidikis’ (C), ‘Amfissis’ (A), ‘Kalamon’, ‘Koroneiki’, ‘Agiou Orous’, and wild olives, as well as the scion x rootstock combinations CxC, MxC, MxM, AxM, CxM, AxA, and CxA were irrigated with a nutrient solution containing 10 mg boron (B)/L for two months. In all the own rooted plants and in the rootstock—scion combinations of the same cultivar stem growth rate was decreased due to high B. The lowest B concentration in leaves and roots was found in ‘Kalamon’ and wild olives, respectively. ‘Megaritiki’ had higher leaf B concentration when grafted on ‘Megaritiki’ or ‘Chondrolia Chalkidikis’ compared to own rooted plants. The same cultivar as own rooted plant had higher root B concentration than as rootstock of the other tested cultivars.