W8 PM Ecotoxicology of Agrochemicals and Pharmaceuticals
Wednesday, 16 November 2005: 1:50 PM - 5:30 PM in 337-338

(SOL-1117-854962) Environmental risk assessment of the use of glyphosate for the control of illicit crops in Colombia.

Solomon, K¹, Anadón, A², Cerdeira, A³, Marshall, J⁴, Sanin, L-H⁵, ¹ University of Guelph, Guelph, ON, Canada² Universidad Complutense de Madrid, Madrid, Spain³ EMBRAPA, Jaguariuna, SP, Brazil⁴ Marshall Agroecology, Barton Winscombe, UK⁵ Autonomous University of Chihuahua, Chihuahua, Mexico

ABSTRACT- Glyphosate has been used for the control of illicit crops in Colombia for several years. In practice, areas of production are identified by multispectral imagery from satellites. Once located, areas of production are mapped with the aid of lower-altitude images and direct aerial observation. GPS coordinates are used to identify locations for application of herbicide by application from fixed-wing aircraft at low altitude. The herbicide, glyphosate, and additional surfactants are applied using raindrop nozzles at rates of 4.8 and 1.2 kg AI/ha. The areas treated represent a fractional percentage of the total area of the country and they may receive applications from 1- 4 times per year. The herbicide and its formulants were tested for toxicity in the standard Tier-1 suite of terrestrial and aquatic organisms. These toxicity values were used to assess potential risk to terrestrial invertebrates and aquatic organisms resulting from a direct overspray of fields and surface waters. Recovery of treated plants was assessed on the basis or recolonization of sprayed areas and the success of replanted areas. Recovery began in less than 21 days and newly planted crops showed successful establishment within 56 days of application. Ecological risk assessment suggested low risk to terrestrial animals and low risks to aquatic organisms, except in shallow static water that may be accidentally over-sprayed. This work was supported by the Organization of American States.

Key words: glyphosate, risk assessment, illicit crops