Weekly Cotton Defoliation Update from Cotton Specialist, Camp Hand:
Temps are going down, meaning we may have to switch some things up this week.
For the most part, temps go from low 90s to high 80s through Wednesday to the high 70s, with even some reported lows in the 50s by Friday. Don’t let it fool you – looks like it will pick back up a little next week.
Defoliating cotton is much easier and cheaper when it is warm outside. Once it cools off, higher rates, and potentially longer wait times from application to harvest are necessary. So, here’s the strategy I would use.
If I had some cotton that was ready and I was ready to go get it, I would defoliate today (Monday) or tomorrow (Tuesday). If I couldn’t get to it by then, I would probably wait until next week.
Some of you may ask why – largely because if I were going to spray on Monday/Tuesday, it would be a different recipe than what I would use Thursday or Friday, and then I will probably go back to the original recipe at the beginning of next week if the forecast holds. Also keep in mind there’s a little chance of rain on Wednesday in many places – just something to keep an eye on.
Recipe for the week:
3.2 – 4 oz/acre thidiazuron
8-12 oz/acre tribufos (higher towards end of week)
32-42 oz/acre ethephon (higher towards end of week)
If I were trying to decide what to do, I may even look at a ginstar type product for spraying on Thursday or Friday if I decided to go down that road. I’d be looking at 6-8 oz/acre plus the ethephon. Doesn’t hurt to add a little thidiazuron to that mix either, particularly in high regrowth areas.
Higher water volumes are always better. 10 GPA is better than 7, 15 better than 10, and 20 better than 15. Since many folks already have the setup for 15, I figure that is the best one to shoot for. You are more likely to have issues with defoliation if you use larger droplets (i.e. dicamba tips), but that can be overcome by increasing water volume. Whatever you decide to do, don’t forget the lessons from UPW when defoliating cotton. These chemistries need to stay on target just like everything else – finish strong.
