Search Results
Batch adsorption experiments were performed to determine the sorption of the nematicide fluensulfone as a technical-grade and a granular formulation (as Nimitz 15G) in six UK arable soils. The Freundlich and equilibrium sorption coefficients and , respectively, were generally low. and correlated positively with soil organic matter in all instances. The sorption kinetics was similar for both forms, but the was about four times lower for Nimitz 15G than the technical-grade, suggesting concentration dependency of fluensulfone sorption. The low sorption of fluensulfone across the soils indicates that partitioning of fluensulfone to the soil liquid phase may be unlimited. Therefore, substantial availability in the soil to be effective is likely. Sorption, therefore, may not limit fluensulfone efficacy. Nonetheless, these results call for cautious use of the nematicide because leaching is possible.
As part of a broader study to evaluate the efficacy of fluensulfone for control of the potato cyst nematode, Globodera pallida, two field experiments in Shropshire (at Woodcote and Howle in 2010 and 2011, respectively) England, were used to monitor the persistence of fluensulfone in potato beds treated with Nimitz 15G® (fluensulfone) at 27 kg ha−1. Fluensulfone dissipated at similar rates in the two fields, with a trend best described by a sigmoidal curve. The time to 50% dissipation (DT50) was 24.3 days at Woodcote, and 23.7 days at Howle. No differences were found between the DT50 for fluensulfone and that observed for fosthiazate. The short DT50 demonstrated for fluensulfone in this study is a positive attribute as this nematicide may pose a negligible hazard to the environment. However, its persistence at an effective dose may be long enough to be effective over the peak hatch period of G. pallida.
The biofumigation potential of leaf and root extracts of Brassica juncea and Raphanus sativus on Globodera pallida were assessed in vitro. In an efficacy study, G. pallida encysted eggs were exposed to six different concentrations of freeze-dried leaf or root extracts for 96 h and assessed for viability using hatching assays in 6-week-old potato root leachates (PRL). For B. juncea extracts an LC50 value of 0.027 mg ml−1 w/v was determined. The LC50 of Raphanus sativus root extracts was 0.032 mg ml−1, whereas leaf extracts were effective only at higher concentrations (⩾0.50 mg ml−1; w/v) and to a lesser extent. Hatching of G. pallida was enhanced in PRL following exposure to lower concentrations (0.063 mg ml−1) of R. sativus leaf extract. An analysis of the types and concentrations of glucosinolate (GSL) present in the freeze-dried tissues revealed that B. juncea leaf tissue was rich in 2-propenyl GSL (≈98%). Root tissue also had a high concentration of 2-propenyl GSL, but the leaf extracts were found to have a higher concentration (⩾90 μmol (g dry weight)−1) when compared with the root extract (⩾10 μmol (g dry weight)−1). Raphanus sativus had two-fold more root GSL, predominantly 2-phenylethyl GSL (⩾50 μmol (g dry weight)−1), when compared with the leaf tissue which was dominated by 4-methylsulfinylbutyl GSL (⩾20 μmol (g dry weight)−1). In summary, the strong suppression of G. pallida encysted eggs exhibited by lower concentrations of B. juncea extracts shows the potential of this species in G. pallida management if effectively incorporated into an integrated potato cyst nematode management scheme. In comparison with B. juncea, the biofumigation potential of R. sativus can be improved by maximising its root biomass production.
This article provides a comparative analysis of the regulation of ammonia emissions, primarily from livestock installations, in Denmark, Germany and the Netherlands. It discusses the challenges of regulating agricultural ammonia emissions in view of the rulings of the Court of Justice of the European Union (cjeu) on Art. 6(3) of the Habitats Directive. It is argued that the need to ensure certainty concerning the absence of significant effects on Natura 2000 sites is challenged by the uncertainties regarding both the state of individual habitat types and the potential impact of individual projects. A more integrated or programmatic approach may provide an alternative approach to individual assessments, but it is necessary to ensure that additional loads from new or enlarged livestock installations are permitted in areas with high ammonia loads only where it is certain that a programmatic approach will ensure that there are no harmful effects. This might be an almost impossible task.