We re-nozzled the tunnel sprayer to obtain greater flow per nozzle with a lower pressure. Specifically, we changed to TeeJet AITX ConeJet Air-induction Nozzles (AITXA8003VK). At 100 psi, these put out 0.467 gpm, so for 16 nozzles the output was 7.5 gpm or, in our case, 95 gallons per acre.
Results were spectacularly better. Even with a reasonably strong breeze parallel with the row, there was virtually no drift. Further, 21 out of every 95 gallons applied per acre were recaptured, giving a final dilute application of 74 gallons per acre for full coverage.