I'm not convinced of the yield hit from off label glyphosate. From what I've seen, the late or high rate of Rup will delay the crop substantially, but it is the rest of the growing season that affects yeild. If you are in an area where moisture is short and heat excessive from here on out, then it would definitely hurt yeild. In my case, we rarely get enough heat to hurt yields, and moisture is rarely limiting. 2 yrs ago I sprayed parts of a field at early flowering. It was hot and dry for a couple of weeks afterwards(unusual), and it fell way behind the unsprayed crop. Then the weather went back to cool and wet as the injured crop was entering full flower, meanwhile, the unsprayed gave up on flowering during the hot weather and was done before the rain came back. Big difference in yield.
Not sure if rr canola is the same over hear in oz but sprayed some canola when it was flowering and had no yield penalty as it was not all the crop and was no difference between what was and wasnt sprayed.
I had a little roundup left over from some late seeded RR canola, and back at the yard sprayed a diagonal strip over where i know there is a bad oat strip on some early canola that was well into bolting and a few blooms and there is no visual indicator yet....(don't mean there won't be a difference when the combine's show up).
Around here lots of spraying going on , put only .25 ltr acre down sprayed later in afternoon.
Not spraying will cost money to, crop just not heavy enough.
Most farmers in NE will struggle to net 25 bu /acre
My guesss tho
" If weeds are bigger than the label indicates as a maximum stage, significant losses from competition have already occurred, and control by herbicides will be reduced, leading to poor or negative return on the herbicide application."