Agriculture

  2009 JUN 4 - (VerticalNews.com) -- "Farming activities are major drivers of the landscape-related ecological patterning because of their multiple influences oil both non-arable and arable landscape elements and mosaics. Uncertainties still remain about the way individual farmer decisions and the aggregation of their activities in space contribute to these mosaics at local landscape scales, therefore about possible levers of action in farms for ensuring sustainable landscapes," scientists writing in the journal Agriculture Ecosystems & Environment report ...read more

  2009 JUN 4 - (VerticalNews.com) -- According to recent research published in the journal Agriculture Ecosystems & Environment, "The present study investigated whether case-specific Monitoring (CSM) Would be an appropriate option to detect possible effects Oil butterflies during commercial cultivation of Bt-maize (Cry1Ab), The analysis of all existing dataset on butterfly communities in Switzerland allowed quantifying the variability in species richness and abundance of nine ecological groups Of butterflies resulting from habitat features, agricultural field management, landscape features, regional farming characteristics, spatial variability and temporal fluctuations. The data set also enabled to estimate the sample size needed to detect potential effects of Bt-maize in a CSM programme within the determined variability. ...read more

  2009 MAY 14 - (VerticalNews.com) -- According to a study from the United States, "An underlying assumption of weed biological control asserts that laboratory-based host specificity testing accurately predicts the realized host range of herbivorous arthropods. We tested this assumption by comparing predicted host specificity with the realized host range of the introduced weevil Oxyops vitiosa (Pascoe)."

  "Laboratory host specificity tests showed that the weevil can complete its development on only a small group of species in the Melaleuca genus, including the target host Melaleuca quinquenervia (Cav.) Blake. Three years after its release, adult weevils readily emigrated from the surrounding M. quinquenervia trees into replicated common gardens but only a small proportion occurred within the canopies of non-Melaleuca species. Adults remained within the canopies of Melaleuca congeners longer than non-Melaleuca and the former recruited 98% of all individuals dispersing from neighboring test plant species. Oviposition was predicted to occur on seven of the 19 species planted in the common gardens but was realized on only four exotic species. Consistent with the prerelease assessments, larvae were observed on four plant species but larval development was limited to Melaleuca congeners. These results lend support to the premise that risk assessments based on physiological host ranges, as characterized by laboratory testing, are conservative when compared to the realized ecological host ranges that occur under field conditions. We conclude that the ecological host range of O. vitiosa is highly restricted and there will be no colonization of species other than the target weed in the adventive range," wrote P.D. Pratt and colleagues, Department of Agriculture ...read more