Spreading and evaporation of glufosinate solution with adjuvants on different weed species

Abstract

The addition of adjuvants to herbicides to improve the effectiveness of spray solutions for weed control has been widely adopted. This research aimed to determine the spread, contact angle, and evaporation time of glufosinate, with and without adjuvants, on the leaf surfaces of four weed species Digitaria insularis (L.) Fedde, Cenchrus echinatus L., Amaranthus viridis L., and Bidens pilosa L.). We used a completely randomized design and a 4 x 4 factorial scheme, with ten replications. The surfaces of four weed species were the first factor and the applied solutions (distilled water, glufosinate herbicide, glufosinate + surfactant, and glufosinate + mineral oil) were the second factor. Concerning droplet deposition, the wide-leaved weeds showed a broader spread and a greater contact angle in contrast to the narrow-leaved ones. The droplet spreading area was negatively correlated with evaporation time and contact angle. We conclude that the spreading area and evaporation time of herbicide droplets depend on the characteristics of each surface area and vary among different weed species. The addition of adjuvants to spray solutions is essential for glufosinate herbicide, particularly on leaf surfaces with higher wax content. © 2025, Federal University of Lavras. All rights reserved.