Can’t spray canola regrowing under swaths

September 23, 2015 - Issue 27

Cut canola plants (see red arrow for cut) are starting to regrow (see area in circle). Credit: Justine Cornelsen

Cut canola plants (see red arrow for cut) are starting to regrow (see area in circle). Credit: Justine Cornelsen


Regrowth in swaths cannot be sprayed. Credit: Justine Cornelsen

Regrowth in swaths cannot be sprayed. Credit: Justine Cornelsen

Rain and delayed harvest have caused some cut canola plants to regrow. This regrowth coming up through swaths can make for increased green matter going through the combine.

This regrowth cannot be sprayed. Once canola is cut, no product can be applied. Pre-harvest intervals are closed for all products, and spraying swaths mean residues will end up in or on the seed resulting in an increase risk of exceeding allowable test levels.

Spraying regrowth in the windrow wouldn’t work that well anyway. Herbicides need to make contact with what they are to control. With most of the target area buried in the swath, there would be an insufficient dose to control regrowing plants.

The only canola fields that can be sprayed are standing crops. Yet because they’re still standing, regrowth from cut stems will not happen. This could be seen as another factor in favour of straight cutting.

Further reading:

Sprouting seeds and cut plant regrowth

Canola Watch