Probably,
Not really sure which one?
Same difference,
It is a chance that we take,
Overlapping residual applications is the solution to the herbicide loss of effectiveness.
The old days practice of, once and done herbicide application, is a distant memory.
The old timers, who started custom applying herbicides in the early 60’s, talked about how they had to convince the farmers that the herbicides really were a good investment.
Seems crazy now to think that, there was a time when herbicides were not available.