The "burn streak pattern " is a classic large-sprayer signature. It is caused by reloading with a new chemical but not flushing the boom of the previous mixture. The "V" shows theflushing of theold chemical, first in the center (shortest path from the tank) and progressing on out to the boom tips. This photo suggests the old chemical was toxic to the new crop.Usually the "V" is made up of weeds because the previous "chemical" was rinse water. It often takes a quarter mile to get the entire boom spraying the correct material. Direct injection, recirculating booms and a very smart operator can reduce this issue. Custom sprayers who are constantly changing crops and chemicals throughout the day are very familiar with this pattern.
Photo courtesy of Bob Recker, Cedar Valley Innovation, Waterloo, Iowa
Pattern diagnosis by a reader from Fairbank, Iowa