CHEMIGATION APPLICATION EFFICIENCY OF OIL-BASED PESTICIDE

Chemical application efficiency of foliar insecticides was evaluated d uring chemigation of field corn by a linear move irrigation machine. C hemical application efficiency, as defined for this study, included ch emical discharge uniformity along a linear move system, chemical depos ition uniformity with height on foliage, and the partition between che mical on soil and foliage and atmospheric drift. Foliar deposition was monitored for both height and distance along the system, and drift vo lume and concentration with distance downwind were measured. Foliage a nd soil deposition along with air drift were compared with injected vo lume. Several chemical injection systems were evaluated: single inject ion port, a multiorifice injector port, and a multiport injection syst em. 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. Ch emical discharge uniformity along the linear move system improved for both multiport and multiorifice injector systems, for increased turbul ence of irrigation water at the single injection port, and for the emu lsifiable formulation.