The effects of herbicides Garlon 3A, Garlon 4, and Tordon 101 on grasses.

Abstract

Herbicides Garlon 3A, Garlon 4, and Tordon 101 are regularly applied over a sixty foot width along the entire route of a pipeline carrying crude oil from Manitoba to Ontario, Canada. The purpose of these chemicals is to prevent dicots, which may damage the pipeline, from growing in the area. The manufacturers claim that these herbicides do not harm grasses. Our purpose was to analyze the effects, if any, that the herbicides may have had on the non-targeted grasses. Four transects were set, two on the pipeline and two on the UMBS ballfield, for a comparison between sites with and without herbicide application. Each transect consisted of six two-by-three meter quadrats, in which we identified and counted all species of grasses present. Distinct trends in the diversity and abundances of grasses were found, although none were statistically significant. More biomass was present on the central quadrats of the pipeline versus that of the ballfield. The Shannon-Weiner diversity index showed that there was a higher level of diversity on the pipeline. Our results lack sufficient evidence, so we are not able to accept or reject our hypothesis. Our observations and tests have led us to believe that there are differences between the past species on the pipeline, the present species on the pipeline, and the species on the ballfield. Although there are a number of environmental variables that may have some effect, we have not ruled out the possibility that herbicides have had an effect on the non-target grasses.