Design of a Seed-Specific Application System for in-Furrow Chemicals

In-furrow chemical inputs such as fungicides, insecticides, and nematicides are generally applied at planting asa continuous band of material. Focusing these applications at the seed and minimizing the amount of chemical appliedbetween seeds has potential to significantly reduce in-furrow inputs. An in-furrow seed-specific application system wasdeveloped to apply discrete bands of liquid chemical to individual seeds during planting. Each seed was detected in the seedtube, seed arrival time at the furrow was estimated, and a chemical band was applied as the seed landed in the furrow. Theseed-specific applicator was evaluated at three field speeds and four spray band lengths during corn and cotton plantings.Accuracy of spray band placement, measured as percent of seeds observed within a sprayed band of soil, ranged from 63%to 97% in corn and from 56% to 98% in cotton, depending on field speed and spray band length. As spray band lengthincreased from 3.8 to 7.6 cm, accuracy (averaged across speeds) increased from 76% to 91% in corn and from 72% to 95%in cotton. Accuracy and field speed were inversely related, with highest accuracies observed at the slowest speed. While theapplicator performed well, further improvements may be possible, especially when operating at high field speeds. Substantialin-furrow material savings are feasible and depend on desired seeding rates and spray band lengths.