Submitted to: North Carolina Weed Science Society Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: March 10, 1999
Publication Date: March 15, 1999
Citation: HANKS, J.E., THOMSON, S.J. ADVANCES IN APPLICATION TECHNOLOGY. NORTH CAROLINA WEED SCIENCE SOCIETY PROCEEDINGS. 1999. Technical Abstract: Sensors that measure unique differences in spectral characteristics of bare soil and green living plants provided the basis for development of a sensor-controlled spray system that applies herbicide only where weeds are detected. This technology was evaluated in the Mississippi Delta Management Systems Evaluation Area (MDMSEA) as a best management practice (BMP) for reduction of herbicide usage in conservation tillage production of cotton and soybeans. The three-year, season-long evaluation indicated an average reduction in herbicide usage of 73 and 49%, respectively for cotton and soybeans. Other studies conducted in cotton, soybeans, and corn indicated an average reduction in herbicide usage of 67% for the 2500 acres treated. Geo-referenced maps of weedy areas were also generated for fields in the MDMSEA. Drift potential of a spray application can be changed significantly by the formulation and nozzle selection. Spray droplet data collected with a Malvern laser particle analyzer indicated little change in spray droplet size for some herbicides, as concentration increases. The percent spray volume in droplets less than 105 microns increased with other herbicides and decreased with some as the concentration increased. Spray adjuvants produced similar results with some of the drift reducing adjuvants providing significant reductions in the percent spray volume in droplets less than 105 microns. Data indicated the percent spray volume in droplets less than 105 microns was reduced approximately 35% with a TurboTeeJet nozzle and a drift reducing adjuvant when compared to an Exteneded Range TeeJet nozzle without adjuvant. These techniques combined with shielded boom applicators provide opportunity for significant reduction in drift potential.