Benchmark study on glyphosate-resistant crop systems in the United States. Part 2: Perspectives

A six-state, 5 year field project was initiated in 2006 to study weed management methods that foster the sustainability of genetically engineered (GE) glyphosate-resistant (GR) crop systems. The benchmark study field-scale experiments were initiated following a survey, conducted in the winter of 2005-2006, of farmer opinions on weed management practices and their views on GR weeds and management tactics. The main survey findings supported the premise that growers were generally less aware of the significance of evolved herbicide resistance and did not have a high recognition of the strong selection pressure from herbicides on the evolution of herbicide-resistant (HR) weeds. The results of the benchmark study survey indicated that there are educational challenges to implement sustainable GR-based crop systems and helped guide the development of the field-scale benchmark study. Paramount is the need to develop consistent and clearly articulated science-based management recommendations that enable farmers to reduce the potential for HR weeds. This paper provides background perspectives about the use of GR crops, the impact of these crops and an overview of different opinions about the use of GR crops on agriculture and society, as well as defining how the benchmark study will address these issues.     

Effect of solid residues from the cellulose industry on plant growth

An alternative use of solid organic and inorganic residues as fertilizers from a Kraft pulp industry was studied. Residues of inorganic nature, such as ashes, fly‐ashes, dregs, grits, as well those rich in organic matter, primary sludge and brown stock rejects, were examined for plant growth enhancement. These residues, all alkaline in nature, used in different concentrations together with soil, bark, organic soil or mixed with a nutrient solution, were tested on the growth of Monterey pine (Pinus radiata), Eucalyptus globulus, rice (Oryza sativa. cv. ‘Diamante’), and duckweed (Lemna minor) under greenhouse and in‐vitro conditions, respectively. Responses varied according to plant species, type, and waste content in combination with substrate. For Monterey pine, substrates including ash, fly‐ash, and dregs promoted growth; in Eucalyptus seedlings dregs and fly‐ash were also beneficial. Primary sludge and ash were favorable for rice growth. Duckweed increased frond number and plant biomass when grown in water containing fly‐ash and primary sludge extracts, combined with nutrient salts.     

Survey of field outbreaks of avian infectious laryngotracheitis in England and Wales.

Field outbreaks of infectious laryngotracheitis in commercial chicken flocks in England and Wales between 1985 and 1988 were investigated. Material from 49 outbreaks was submitted to Liverpool University, and virus was isolated from 17 of them. The results of a questionnaire on each outbreak are described. Generally, the disease was of moderate severity, and mainly affected laying flocks; it occurred in birds of a wide age range but most of the outbreaks were in birds between 10 and 20 weeks of age. The disease was not seen more frequently at any particular time of the year, and there was no evidence of a common source of infection. Three of the affected flocks had recently been moved and were beginning to lay; these stresses may have caused the re-excretion of latent virus.     

Effect of ammonia on the quantitative clearance of Escherichia coli from lungs, air sacs, and livers of turkeys aerosol vaccinated against Escherichia coli

Turkeys were given an aerosol vaccine to determine their ability to clear a virulent inhaled pathogenic strain of Escherichia coli, while they were being maintained in the presence of atmospheric NH3. Turkeys were exposed to 2 concentrations of NH3 (10 and 40 microliters/L of air). More E coli was found in lungs, air sacs, and livers of turkeys exposed to NH3. Turkeys not exposed to NH3 had better clearance of E coli. Vaccination against E coli improved the rate of clearance of E coli in birds not exposed to NH3.     

Penetration and metabolism of topically applied permethrin and cypermethrin in pyrethroid-tolerant Wiseana cervinata larvae

The penetration, excretion, and metabolism of topically applied [¹⁴C]permethrin and [¹⁴C]cypermethrin have been examined in larvae of the porina moth Wiseana cervinata to determine the factors which affect body levels of unchanged pyrethroids. Metabolism was by hydrolysis and to a lesser extent oxidation and the primary metabolites were quickly conjugated to water-soluble products. Little excretion occurred and body levels of unchanged pyrethroids were dependent on the interaction of penetration and metabolism. cis-Cypermethrin was more resistant to metabolism than trans-cypermethrin and cis- and trans-permethrin. trans-Permethrin most readily penetrated into larvae. The body levels of unchanged permethrin were enhanced by pretreatment of larvae with the metabolic inhibitors carbaryl or piperonyl butoxide. Tolerance of the pasture pest porina to the synthetic pyrethroids is discussed in relation to these findings.