Defoliation Update – Dr. Hand
It’s that time of year again. The smell of Folex is in the air and I am starting to get THE question: “Camp, what’s the recipe for the week??”
In my travels across the state, there are a good many fields that are ready to defoliate. Of course, in the latest rendition of the Cotton Team Newsletter, there is a section on defoliation timing. Also keep in mind Percent Open Boll and Nodes Above Cracked Boll (NACB).
Over the next week we are looking at a different temperature pattern than we normally see. Up to now people have been using 6-8 oz/acre of Folex in the tank, but with it cooling down towards Friday we may need to be looking at up to 10 oz/acre in some cases. In the North part of Georgia (thinking Morgan, Chattooga, Bartow counties), I might be thinking Ginstar + Prep (8 + 42 oz/acre, respectively).
One other thing to keep an eye on is rainfall. On Wednesday and Thursday it looks like there are chances for showers (less than 50%, but could still happen!). Rainfree periods this time of year are a big deal, particularly when one of our most used defoliants (Dropp/Freefall/Klean-pik, active ingredient Thidiazuron) has a rainfree period of 24 hrs. Fortunately it is rarely applied alone, so we can likely operate on a 12 hr rainfree period. Rainfree periods on other common defoliants for GA growers are listed in the PDF attached to this email, which is a good “one pager” for all things defoliation. Looks like by Friday and into the weekend it should be clear.
Temps this week will drop by Friday, meaning higher rates. According to the rate table included in the newsletter, we need to be around 3-4 oz Dropp (Thidiazuron), 8-10 oz Folex (Tribufos), and 32-42 oz Prep (Ethephon) for South Georgia. Use higher rates of Dropp where there is significant regrowth or risk of regrowth. Higher rates of Folex and Prep on cooler days.
If you decide to use a PPO inhibiting herbicide in your defoliant mix (Aim, ET, etc.), please be sure to study the rates beginning on page 143 of the Cotton Production Guide. Generally we like lower rates in higher temperatures. If you decide to use a PPO, take Folex out of the tank.