Effect of fungicides on Fusarium ear blight and mycotoxin accumulation in winter wheat (<i>Triticum aestivum</i> L.)

In order to determine the effect of a range of fungicide products, dose rate and time of application on the development of Fusarium head blight (FHB) and mycotoxin contamination of winter wheat, a series of field experiments (1998-2001) were carried out. A mixture of the fungicides metconazole+azoxystrobin provided the most significant reduction of (FHB) severity (63%) in comparison with control treatments followed by mectonazole (39%) and tebuconazole (45%) applied at both full and half the manufacturers recommended dose rate. Quantification of Tri5 DNA and deoxynivalenol (DON) concentration in harvested grain indicated that metconazole and tebuconazole were the most efficacious fungicides at reducing colonisation of grain by trichothecene-producing Fusarium species and DON content. Azoxystrobin had no effect on Tri5 DNA and DON concentration in grain, but significantly reduced the incidence of Microdochium nivale infected wheat grain. Fungicides applied early in the growing season (GS 31 and 39) were less effective at controlling disease than those applied later in the season (GS 39 and 59). Indeed, it was evident that the timing of fungicides was critical for the effective control of FHB and DON with the best control achieved when fungicides were applied either two days before or two days after the artificial inoculation of wheat ears with FHB causing pathogens. Regression analysis on field trial data revealed that fungicides were able to influence DON content in harvested wheat grain by affecting the extent of grain colonisation by mycotoxin producing species. Since published literature has suggested that fungicides can directly influence DON contamination by imparting a stress influence on FHB pathogens, glasshouse studies were undertaken to determine the effect of a range of dose rates of the fungicides azoxystrobin and metconazole against FHB and DON in wheat plants inoculated with either Fusarium culmorum or F. graminearum. Results revealed that metconazole was effective at reducing FHB, Tri5 DNA and DON and that a rate response was observed as dose rate was increased from one quarter to double the manufacturer's recommended dose rate. Although azoxystrobin reduced FHB, Tri5 DNA and DON content compared to untreated controls, no dose rate response was observed. Regression analysis of glasshouse data supported those obtained from field studies, suggesting that fungicides are able to influence DON content indirectly by affecting the extent of grain colonisation by F. culmorum and F. graminearum. Further glasshouse studies were conducted to determine the interactions between Alternaria tenuissima, Cladosporium herbarum, M. nivale and F. culmorum and the effect of fungicides on these interactions. Introducing C. herbarum or M. nivale to wheat ears at GS 57, before inoculation with F. culmorum at GS 65, resulted in a significant increase in FHB severity, Tri5 DNA and DON concentration in grain. Applying azoxystrobin to wheat ears after the introduction of M. nivale at GS 57, increased DON concentration in grain by 56%. The significance of interactions between saprophytic fungi, M. nivale and Fusarium species on fungicides efficacy against FHB and DON is discussed

The effect of wheat cultivars on the growth performance and energy retention of broiler chickens

The nutritive values of twelve samples of different UK wheat cultivars from two different growing years were assessedA. serieso f chicken feeding experimentsw ere conducted to examine the relationships between chemical composition, grain quality and energy content of the wheat samples and the growth performance of broiler chickens when fed these wheat samples as part of nutritionally complete diets. The efficiency of utilization of apparent metabolisable energy (AMEn) of wheat samples as a source of net energy (NE) was studied. Step-wisc multiple regression analysis indicated that the content of total starch in the wheat samples and the arnylosea: mylopectin ratio in the starch were the main predictors of growth, feed intake and FCR of the broilers. Increasing starch and arnylose content in the wheat cultivar samples gave increasing weight and feed intakes. The Hagberg falling number was also significantly (P0.05) differences in broiler growth performance. The influence of different amylose: amylopectin ratios on the physical nature of the starch granule may therefore be more important than their effects in changing the total dietary supply of those starch components. Although the net energy concentration of a wheat sample was related (p<0.05, r2=0.42) to its determined AME, there was still unexplained variation (about 60%) in the cilicicncy of utilization of AME as a source of NE. A proportion of this variation was, however, explained (p<0.05, r2=0.40) by differences in the water-extract viscosity of the wheat samples. Different ileal viscosities, due to feeding different wheat cultivars, may result in variation in the amount of intestinal fermentation of nutrients and so altcr the NENE ratio of whcat-based diets

Aquifer thermal energy storage (ATES) system application for district heating and cooling

Aquifer thermal energy storage (ATES) systems in combination with groundwater heat pumps (GWHP) are promising and effective alternatives for integrated heating and cooling energy supply in buildings and district networks. In the present Thesis ATES systems are presented and addressed from different perspectives, such as their technical rationale, economic feasibility and environmental impact. Groundwater flow and thermal models are developed and calibrated, using a variety of available data sources (National Land Survey of Finland, Finnish Environment Institute) and tools (EXCEL, QGIS, MODFLOW, MT3DMS). Heat pump COP estimation analytical model is also implemented and coupled with the groundwater models. The purpose was to study different energy scenarios for ATES integration within the existing Pukkila's district heating network (Nivos Energia) as well as the long-term environmental flow and thermal impact generated to aquifer groundwater areas. Among the different researched scenarios, the most feasible strategy is to introduce a roughly constant cooling demand (proceeding from e.g. data center or industrial waste heat) in combination with the existing local district heating demand. The introduction of variable cooling demand using standard office simulated data is also modeled, having shown promising results. On the other hand, the "only heating" integration scenario has poor economic results, at least for the assumed present level of boiler's fuel price, and is reasonably feasible only in the case when prices increase. ATES systems are an efficient and a sustainable alternative for traditional fossil fuel boilers due to their capacity to annually store and recover cooling & heating energy from the subsurface. Significant technical and economical improvement could be achieved when simultaneous or seasonable cooling and heating loads are dispatched, within integrated district energy (heating & cooling) networks

Maximal integral point sets over Z^2

Geometrical objects with integral side lengths have fascinated mathematicians through the ages. We call a set P = {p1,..., pn} ⊂ Z² a maximal integral point set over Z 2 if all pairwise distances are integral and every additional point pn+1 destroys this property. Here we consider such sets for a given cardinality and with minimum possible diameter. We determine some exact values via exhaustive search and give several constructions for arbitrary cardinalities. Since we cannot guarantee the maximality in these cases we describe an algorithm to prove or disprove the maximality of a given integral point set. We additionally consider restrictions as no three points on a line and no four points on a circle

Los Acuerdos sobre el Estatuto de las Fuerzas Armadas Extranjeras como límite a la actividad jurisdiccional de la Corte Penal Internacional

El presente trabajo examina algunas de las limitaciones jurisdiccionales que impiden a la Corte Penal Internacional ejercer de modo efectivo su competencia sobre los nacionales de Estados terceros, aun cuando el crimen se haya cometido en el territorio de un Estado Parte en el Estatuto de Roma. En su primera parte, el artículo profundiza en la inmunidad de jurisdicción penal de los agentes militares como funcionarios del Estado de la nacionalidad. En segundo lugar, analizamos la conformidad de los acuerdos del artículo 98.2 del Estatuto, también denominados Acuerdos sobre el Estatuto de las Fuerzas Armadas Extranjeras, con las disposiciones de éste, al originarse en estos casos una especie de inmunidad procesal ad hoc que condiciona la operatividad de la Corte

Issues Associated with Genetic Diversity Studies of the Liver Fluke, Fasciola Heptica (Platyhelminthes, Digenea, Fasciolidae)

Space scienc

El ejercicio de la competencia de la Corte Penal Internacional por iniciativa del Consejo de Seguridad de las Naciones Unidas

El reconocimiento explícito del poder de activación de la jurisdicción de la Corte Penal Internacional a un órgano eminentemente político, como el Consejo de Seguridad de las Naciones Unidas, y la consiguiente potestad de remisión de una situación a la Fiscalía, son el resultado natural de la función primaria que le corresponde como órgano principal al que la Carta de las Naciones Unidas confiere la responsabilidad primordial de mantener la paz y la seguridad internacionales. Precisamente la diversa naturaleza de ambas instituciones es la cuestión de mayor envergadura en orden a garantizar la jurisdicción de una Corte libre de manipulaciones políticas. Su eficacia como institución independiente, de carácter permanente, vinculada sustancial, funcional y económicamente a la Organización de las Naciones Unidas, está supeditada a la activa colaboración con el Consejo de Seguridad, con el fin de garantizar el ejercicio de sus funciones y la realización de sus propósitos