Another spraying season is upon us and it's already happened – someone has not cleaned out a sprayer properly and damaged a sensitive crop with glyphosate, active ingredient in Roundup.
In this case, a wheat field was sprayed for disease control with a fungicide. Apparently there was still glyphosate in the system. The first couple of acres sprayed were clearly damaged and may not recover.
One person who works with sprayers says the problem could be that the tank wasn't rinsed properly. There is a procedure recommended for rinsing spray tanks when switching from one pesticide to another pesticide, and it should be followed thoroughly.
However, the other problem could be that the booms weren't flushed out. In 90 or 120 foot booms, a significant amount of spray can still remain in the booms.
Manufacturers today are working on systems that cause nozzles to stop dripping and leaking material exactly when the sprayer is shut off.
However, in this situation that wouldn't necessarily help. If the nozzles quit dripping after the last use and the line remained full of spray, it could actually add to the problem the next time the person took the sprayer to the field to spray fungicide without cleaning lines first.
Instead, the lines need to be flushed in a safe location in a responsible manner so they are empty and clear of glyphosate or whatever else is being sprayed. The system that prevents drip on the end rows and on point rows while spraying is good, but it doesn't solve the problem of making sure booms don't contain spray products that would ham the crop in the next use of the sprayer.