U.S. Department of Agriculture: Agricultural Research Service, Lincoln, Nebraska


Document Type


Date of this Version



Pest Manag Sci 2010; 66: 1148–1154


This article is a US Government work and is in the public domain in the USA

DOI 10.1002/ps.1996


BACKGROUND: Glyphosate drift from aerial application onto susceptible crops is inevitable, yet the biological responses to glyphosate drift in crops are not well characterized. The objectives of this research were to determine the effects of glyphosate drift from a single aerial application (18.3m swath, 866 g AE ha−1) on corn injury, chlorophyll content, shikimate level, plant height and shoot dry weight in non-glyphosate-resistant (non-GR) corn.

RESULTS: One week after application (WAA), corn was killed at 3m from the edge of the spray swath, with injury decreasing to 18% at 35.4m downwind. Chlorophyll content decreased from 78% at 6m to 22% at 15.8m, and it was unaffected beyond 25.6m at 1 WAA. Shikimate accumulation in corn decreased from 349% at 0m to 93% at 15.8m, and shikimate levels were unaffected beyond 25.6m downwind. Plant height and shoot dry weight decreased gradually with increasing distance. At a distance of 35.4m, corn height was reduced by 14% and shoot dry weight by 10% at 3WAA.

CONCLUSIONS: Corn injury and other biological responses point to the same conclusion, that is, injury from glyphosate aerial drift is highest at the edge of the spray swath and decreases gradually with distance. The LD50 (the lethal distance that drift must travel to cause a 50% reduction in biological response) ranged from 12 to 26m among the biological parameters when wind speed was 11.2 kmh−1 and using a complement of CP-09 spray nozzles on spray aircraft.