ABSTRACT

Agricultural engineers at The University of Tennessee have developed a seed-specific chemical delivery system that applies discrete bands of liquid chemical to individual seeds at planting. This system allows farmers to minimize the amount of in-furrow chemical applied between seeds, thus generating cost savings and more efficient production. During 2003, improvements were incorporated into the system, and an updated prototype was field tested. Tests were conducted to evaluate applicator performance in terms of numbers of seeds covered with spray material. Tests included three ground speeds (3.0, 4.5, and 6.0 mph), four spray band lengths (1.5, 2.0, 2.5, and 3.0 in.), and two seed types (cotton and corn). While planting at 3.0 and 4.5 mph, over 84% of seeds were covered using band lengths of at least 2.0 in. Accuracy was reduced, however, when planting at 6.0 mph, with only about 75% of seeds being covered by 2.0-in. bands at that speed. Field observations suggested that seeds often bounce forward in the furrow when the planter is operated at 6.0 mph, so the control system was modified to compensate. An additional test was conducted to allow evaluation of the design change. Substantial performance improvement was demonstrated at 6.0 mph, with at least 85% of corn and cotton seeds covered by 2.0-in. bands. In addition to system performance tests, a two-year field study designed to evaluate the effectiveness seed-specific fungicide application in cotton was completed in 2003. This test included in-furrow treatment with Terraclor Super X 2.5 EC, which was applied both conventionally and seed-specifically. Seed-specific application reduced overall application amounts by about 50%. Plots were inoculated with Pythium spp. and Rhizoctonia solani fungi, and stand counts were used to quantify disease severity. Significant differences (α = 0.05) were not detected between stand count means from plots receiving conventional and those receiving seed-specific treatment in either year. Results suggested that fungicide applied between cottonseeds contributed little to seedling disease control in the study.