This research can help improve our knowledge and understanding on how to make dicamba applications with the required nozzles to reduce drift potential while maximizing deposition onto Palmer amaranth, waterhemp, and grass species. By having this information, we will be able emphasize the situations, such as high weed densities, in which failures of herbicide applications are more likely to occur with the required low drift nozzles. Information will be extended to soybean producers, crop consultants, extension agents, agricultural retailers, and industry representatives through various mechanisms including newsletters, meetings and field days.

*1. State of the Project Objective(s):

The objective was to determine the influence of nozzle design, droplet size, and weed density on the disposition and efficacy of glyphosate plus dicamba. The primary target species were goosegrass, Palmer amaranth, and waterhemp. Evaluations of goosegrass and Palmer amaranth have been completed.

*ii. Statement of quantifiable progress toward project objective(s) achieved during this reporting period.

Field trials and greenhouse trials evaluating goosegrass and Palmer amaranth density and nozzle design were conducted and completed in the summer and Fall of 2018. Data analysis completed for experiments.

Results have been presented at county, state, national, and international conferences.

*iii. Activities planned between now and the next reporting period.

All research activities completed and final reports are being finalized for submission.

iv. Problems and/or obstacles that may impact the completion date, cost or scope of the project.

Waterhemp and Palmer populations at non-UK sites were not sufficient to conduct a proper density experiment. A complementary Palmer amaranth density trial was conducted in the greenhouse.