We’ve been inundated with calls this week regarding product selection for harvest aids moving forward. Several fields have been defoliated over the past couple of weeks, with widespread defoliation occuring now. Product performance can be largely dependent on weather at the time of application and for several days thereafter, which is why we wanted to provide this update.

Regrowth and Temperatures:

Several folks have been using the tried and true tankmixtures that have performed very well in the past. Such tankmixtures include Folex/Prep/Freefall, Folex(low rate)/Finish/Prep/Freefall etc. In most years, these mixtures work great. For the past couple of weeks, we have been right on the line regarding temperatures required for decent performance with TDZ materials (Dropp, FreeFall, several other generics). Such temperatures includes highs in high 70’s – low 80’s and lows ranging from 55-60 degrees. TDZ will provide some activity in these temperatures, although it’ll be slower and probably not ideal. Given the amount of regrowth that we are dealing with, we have recently been encouraging folks to switch to a Ginstar-type product (Ginstar, Adios, CutOut, other tradenames) in their tankmixtures. Such tankmixtures would include Ginstar/Prep or Ginstar/Finish. According to the weather forecast that we can see right now, it appears that we will have another cool-down beginning this weekend, with highs ranging from the mid 60’s to mid 70’s, and lows ranging from the mid 40’s to the mid 50’s. Now is a clear-cut time to make the switch to Ginstar-type tankmixtures, as the activity of TDZ is expected to diminish rather rapidly. This has been a bad year for regrowth thus far. Cooler weather will likely slow the development of regrowth, but regrowth is already present in most fields and will continue to progress, albeit at a slower rate. We will still have to contend with it for a while.

Boll Opening:

Several folks have been using Finish-type tankmixtures, simply because it has performed well in the past. Finish-type products offer decent defoliation (when tankmixed properly with other materials), more rapid boll opening in both warm and cool weather, and better boll opening during cooler weather, especially for bolls of questionable maturity. The advantages of using a Finish-type product is harvesting sooner when used in warmer weather, and better overall boll opening and potentially higher yields when we have a strong top crop, especially when Fall temperatures are cooler. When there isnt much of a top crop, or when all but 1-2 very mature bolls are already open, there isnt alot of advantage to using these products. Regular ethephon, when used at correct rates, can effectively open very mature bolls, especially when there is only 1-2 bolls per plant yet to open naturally. Therefore growers are encouraged to evaluate their top crop thoroughly to determine if there is even a top crop present, and also slice open any closed bolls that are harvestable to determine if they are mature or may need more encouragement to open. Riding by fields might suggest we have a normal crop with decent stalk height etc. However, upon closer evaluation, the top 1/3 or so of the plant may be barren, due to drought that occurred in August. This may vary from field to field and even within fields. The only way to know is to thoroughly evaluate it.

Standing recommendations:

• defoliate on a sunny day, preferably warm. Avoid defoliating in overcast conditions or when rain is expected within a few hours.
• use no less than 15 gallons per acre, preferably 20 GPA
• avoid using large-droplet nozzles (TTI, AI, others) unless your plants are short and you have a very open canopy. Flat-fans or Twin-fan nozzles provide a good mixture of large/medium/fine droplets for better coverage. This is more important in years like this when we are trying to remove very dense basal regrowth at the bottom of the canopy.