DEFOLIATION TRIAL COMMENTS
By: Danny
Bennett
Cotton
defoliation trials for GAPAC were applied at four locations across the
state. GAPAC consultants
picked the locations, trying to choose a representative field for their
area. Treatments were chosen
by participating company representatives.
Applications were made by Danny Bennett and Lee Dykes.
Treatments were applied with a CO2 spraying system mounted on a
tractor sprayer. All eighteen
treatments went out within a three-hour period.
A five-row by 50 ft. treatment was our standard plot size.
The first treatments went out on September 17 (Saturday), and all
treatment applications were completed by September 20 (Tuesday).
Weather conditions were unusually warm.
Most of the cotton was in good condition to defoliate.
All treatments were more active than typically expected.
Ratings were made at four days after treatment and again at 10 –
11 days.
Carl Hobbs’ plots in Turner county were an exception.
A 6-day rating was also made because at 4 days, the plots were not
progressing as fast as the others were.
Growers in the area had done very little
defoliation application on their fields prior to our defoliation test
starting.
Bleckley
County
: Spray date --
9-17-05
. Consultant: Michael
Williams. Cotton at this site
was very mature and ready for defoliation.
It was a dryland field, but did receive adequate rainfall and had a
good crop set. Most of the
plots could have been picked within five days after the treatment.
Houston
County
: Spray date –
9-17-05
. Consultant: Paul Brown.
Cotton at this site was irrigated, two-bale, plus potential cotton.
This field was at the right stage for “textbook” defoliation
timing. Treatments performed
well at this site because the cotton was in good condition and ready to
defoliate. This was one of the
better sites for uniformity.
Turner
County
: Spray date –
9-18-05
. Consultant: Carl Hobbs.
This field appeared to have suffered from drought conditions for the
previous two – three weeks. The
cotton was still under drought stress and defoliates were not taken up
(due to plant condition) as well as normal.
We were one week to ten days earlier than when most producers would
have normally defoliated. The
condition of the cotton at this site was typical of dryland conditions
over the past ten years.
Seminole
County
:
Spray date –
9-20-05
. Consultant: Wes Briggs.
This was irrigated, two-bale, plus potential cotton.
We were probably one week to ten days ahead of typical defoliation
timing. This was an excellent
site to evaluate the treatments. The
grower had just irrigated the cotton for the last time on the day before
we made our treatments (treated area was furthest along; irrigation was
mainly for other areas of the field that were not as far along).
The cotton was not under any drought stress, probably helping the
treatments move in faster.
Overall comments:
I am still waiting for a “normal” crop year.
Each year is different. Crop
conditions and weather play a major role in determining how defoliates
perform. Recommendations need
to be tailored for individual situations.
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