Chemigation Application Efficiency of Oil-based Pesticide
Chemical application efficiency of foliar insecticides was evaluated during chemigation of field corn by a linear move irrigation machine. Chemical application efficiency, as defined for this study, included chemical discharge uniformity along a linear move system, chemical deposition uniformity with height on foliage, and the partition between chemical on soil and foliage and atmospheric drift. Foliar deposition was monitored for both height and distance along the system, and drift volume and concentration with distance downwind were measured. Foliage and soil deposition along with air drift were compared with injected volume. Several chemical injection systems were evaluated: single injection port, a multiorifice injector port, and a multiport injection system. Soybean oil and dye tracer were used to simulate a nonemulsifiable pesticide. A formulation of soybean oil and an emulsifiable pesticide, Lorsban-4E, were also injected through the single injection port. Chemical discharge uniformity along the linear move system improved for both multiport and multiorifice injector systems, for increased turbulence of irrigation water at the single injection port, and for the emulsifiable formulation.