Galinsoga parviflora Response to Different Application Rates of the Herbicide Chwastox Turbo 340 SL in Spring Barley

Abstract

The aim of this study was to evaluate the response of <em>Galinsoga parviflora </em>to different doses of the herbicide Chwastox Turbo 340 SL [2-methyl-4- chlorophenoxyacetic acid (MCPA) + dicamba] used alone and with an adjuvant. The study was conducted on the spring barley cultivar ‘Suweren.’ During the tillering stage of spring barley, a weed control treatment was applied using Chwastox Turbo 340 SL at a rate of 100% and at rates reduced by 33% and 50%, and was applied either alone or with an oil adjuvant. Plots without herbicide and adjuvant application were the control treatment. The present study showed that in spring barley the largest plants of <em>G. parviflora</em>, which produced the highest number of branches, flower heads, and achenes, occurred in the control treatment where no herbicide and adjuvant were applied. Morphology, productivity, and biomass were not found to vary greatly between <em>G. parviflora </em>plants occurring in the plots where the reduced rates of Chwastox Turbo 340 SL and in those where the manufacturer’s recommended rate were applied. The number of achenes produced by <em>G. parviflora </em>was positively correlated with plant height and negatively with plant biomass. The germination capacity of <em>G. parviflora </em>diaspores was not significantly different between the herbicide protection treatments.