2015 Harvest Aid Trial – 19 DAT Data
October 14, 2015
Today I gathered 19 DAT data from our 2015 Harvest Aid Trial. Harvest aids and their uses in cotton have always been more art than science. This season does seem to be shaking up our standards for expected product performance a bit. Both from this trial and what I am seeing in the field indicates the uniqueness of the season.
My first observation is that bolls are maturing well and the majority of fields are either ready for harvest aids or are nearing it, the odd and very late fields aside. I am not concerned, for the most part, about being able to open bolls at this time. My second, and main observation, is that the leaves are very hard to knock off the plant this season, much more so than I have experienced. The results of this trial point to this trend. Straight ethephon, even at higher rates tending into the lower 40 oz. range are not dropping leaves like I would normally expect. Even adding some of our usually very useful and popular PPOs are not returning the defoliation I have come to expect over the years, with a few exceptions (please note data below for performance and/or product exception). I am not noting any major issues with leaf stick, although we do have differences in this trial, the amount is too low to be a major concern. A touch of defoliant added to solid rates of ethephon, something I have shied away from in recent years due to past performance issues, do seem to be working better and much like what I would expect from those higher rates of ethephon in most seasons. I have not seen any one treatment that I can stamp as a one shot treatment this year, even at 21 DAT. We often say that every season, but the stubbornness of the leaves really brings this statement to absolute fact this season. I am also seeing issues with regrowth following the first treatment and under the recent weather pattern we have had.
So, on to the results of this trial. This year the trial is on Mike Goss’ Farm approximately 6 ½ miles southwest of Tulia. For this trial, we selected 7 cotton harvest aid treatments including an untreated check of interest to area producers and Ag industry. The trial is a small plot RBD replicated 4 times. Plots are 4 40-inch rows wide X 38-feet long. Data collected today was % open boll, % defoliated, % green leaves still attached, % stuck leaves, and today’s data includes a 0-10 regrowth rating with 0 representing no regrowth. At the time of treatment on September 25th, this field was only at 20 % open boll and not truly ready for a blanket harvest aid treatment but was one of the most mature in the area. It was selected for the purpose of an early look at harvest aid performance and to be readily available for the Swisher Cotton Day on October 8th.
% Open Boll @ 19 DAT
% Green leaves still on the plant @ 19 DAT
% Defoliation @ 19 DAT
% Stuck Leaves at 19 DAT
Regrowth rating on 0-10 scale with 0=no regrowth @ 19 DAT